MC68HC11E9BCFU2 [NXP]

8-BIT, MROM, 2MHz, MICROCONTROLLER, PQFP64, QFP-64;
MC68HC11E9BCFU2
型号: MC68HC11E9BCFU2
厂家: NXP    NXP
描述:

8-BIT, MROM, 2MHz, MICROCONTROLLER, PQFP64, QFP-64

时钟 微控制器 外围集成电路
文件: 总242页 (文件大小:1675K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
M68HC11E Family  
Data Sheet  
HC11  
Microcontrollers  
M68HC11E  
Rev. 5.1  
07/2005  
freescale.com  
MC68HC11E Family  
Data Sheet  
To provide the most up-to-date information, the revision of our documents on the World Wide Web will be  
the most current. Your printed copy may be an earlier revision. To verify you have the latest information  
available, refer to:  
http://freescale.com/  
The following revision history table summarizes changes contained in this document. For your  
convenience, the page number designators have been linked to the appropriate location.  
Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc.  
© Freescale Semiconductor, Inc., 2005. All rights reserved.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
3
Revision History  
Revision History  
Revision  
Level  
Page  
Number(s)  
Date  
Description  
2.3.3.1 System Configuration Register — Addition to NOCOP bit description  
Added 10.21 EPROM Characteristics  
44  
May, 2001  
June, 2001  
3.1  
175  
10.21 EPROM Characteristics — For clarity, addition to note 2 following the  
table  
3.2  
3.3  
175  
110  
153  
154  
157  
163  
167  
169  
December,  
2001  
7.7.2 Serial Communications Control Register 1 — SCCR1 bit 4 (M)  
description corrected  
10.7 MC68L11E9/E20 DC Electrical Characteristics — Title changed to  
include the MC68L11E20  
10.8 MC68L11E9/E20 Supply Currents and Power Dissipation — Title  
changed to include the MC68L11E20  
10.10 MC68L11E9/E20 Control Timing — Title changed to include the  
MC68L11E20  
10.12 MC68L11E9/E20 Peripheral Port Timing — Title changed to include the  
MC68L11E20  
July, 2002  
4
10.14 MC68L11E9/E20 Analog-to-Digital Converter Characteristics — Title  
changed to include the MC68L11E20  
10.16 MC68L11E9/E20 Expansion Bus Timing Characteristics — Title  
changed to include the MC68L11E20  
10.18 MC68L11E9/E20 Serial Peirpheral Interface Characteristics — Title  
changed to include the MC68L11E20  
172  
175  
— Title changed to include the MC68L11E20  
11.4 Extended Voltage Device Ordering Information (3.0 Vdc to 5.5 Vdc) —  
Updated table to include MC68L1120  
181  
Format updated to current publications standards  
Throughout  
23  
1.4.6 Non-Maskable Interrupt (XIRQ/VPPE) — Added Caution note pertaining  
to EPROM programming of the MC68HC711E9 device only.  
June, 2003  
July, 2005  
5
6.4 Port C — Clarified description of DDRC[7:0] bits  
100  
10.21 EPROM Characteristics — Added note pertaining to EPROM  
programming of the MC68HC711E9 device only.  
175  
5.1  
Updated to meet Freescale identity guidelines.  
Throughout  
M68HC11E Family Data Sheet, Rev. 5.1  
4
Freescale Semiconductor  
List of Chapters  
Chapter 1 General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13  
Chapter 2 Operating Modes and On-Chip Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29  
Chapter 3 Analog-to-Digital (A/D) Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57  
Chapter 4 Central Processor Unit (CPU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65  
Chapter 5 Resets and Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79  
Chapter 6 Parallel Input/Output (I/O) Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97  
Chapter 7 Serial Communications Interface (SCI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105  
Chapter 8 Serial Peripheral Interface (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119  
Chapter 9 Timing Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127  
Chapter 10 Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .149  
Chapter 11 Ordering Information and Mechanical Specifications . . . . . . . . . . . . . . . . . .177  
Appendix A Development Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .187  
Appendix B EVBU Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .191  
AN1060 — M68HC11 Bootstrap Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .193  
EB184 — Enabling the Security Feature on the MC68HC711E9 Devices  
with PCbug11 on the M68HC711E9PGMR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229  
EB188 — Enabling the Security Feature on M68HC811E2 Devices  
with PCbug11 on the M68HC711E9PGMR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .233  
EB296 — Programming MC68HC711E9 Devices with PCbug11  
and the M68HC11EVBU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .237  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
5
List of Chapters  
M68HC11E Family Data Sheet, Rev. 5.1  
6
Freescale Semiconductor  
Table of Contents  
Chapter 1  
General Description  
1.1  
1.2  
1.3  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
Pin Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
1.4  
1.4.1  
VDD and VSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
1.4.2  
1.4.3  
1.4.4  
1.4.5  
1.4.6  
1.4.7  
1.4.7.1  
1.4.8  
1.4.9  
1.4.10  
1.4.10.1  
1.4.10.2  
1.4.10.3  
1.4.10.4  
1.4.10.5  
RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22  
Crystal Driver and External Clock Input (XTAL and EXTAL) . . . . . . . . . . . . . . . . . . . . . . . . 22  
E-Clock Output (E). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23  
Interrupt Request (IRQ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23  
Non-Maskable Interrupt (XIRQ/VPPE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23  
MODA and MODB (MODA/LIR and MODB/VSTBY). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
VRL and VRH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
STRA/AS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25  
STRB/R/W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25  
Port Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25  
Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25  
Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27  
Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27  
Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28  
Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28  
Chapter 2  
Operating Modes and On-Chip Memory  
2.1  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  
2.2  
Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  
Single-Chip Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  
Expanded Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  
Test Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  
Bootstrap Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  
2.2.1  
2.2.2  
2.2.3  
2.2.4  
2.3  
2.3.1  
2.3.2  
2.3.3  
2.3.3.1  
2.3.3.2  
2.3.3.3  
Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31  
RAM and Input/Output Mapping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39  
Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40  
System Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42  
System Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43  
RAM and I/O Mapping Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45  
System Configuration Options Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46  
2.4  
2.4.1  
2.4.2  
EPROM/OTPROM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47  
Programming an Individual EPROM Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48  
Programming the EPROM with Downloaded Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
7
Table of Contents  
2.4.3  
EPROM and EEPROM Programming Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . 49  
2.5  
2.5.1  
EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51  
EEPROM and CONFIG Programming and Erasure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51  
Block Protect Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51  
EPROM and EEPROM Programming Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . 53  
EEPROM Bulk Erase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54  
EEPROM Row Erase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54  
EEPROM Byte Erase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55  
CONFIG Register Programming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55  
EEPROM Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55  
2.5.1.1  
2.5.1.2  
2.5.1.3  
2.5.1.4  
2.5.1.5  
2.5.1.6  
2.5.2  
Chapter 3  
Analog-to-Digital (A/D) Converter  
3.1  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57  
3.2  
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57  
Multiplexer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57  
Analog Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57  
Digital Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59  
Result Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59  
A/D Converter Clocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59  
Conversion Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59  
A/D Converter Power-Up and Clock Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60  
Conversion Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61  
Channel Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61  
Single-Channel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61  
Multiple-Channel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62  
Operation in Stop and Wait Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62  
A/D Control/Status Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62  
3.2.1  
3.2.2  
3.2.3  
3.2.4  
3.2.5  
3.2.6  
3.3  
3.4  
3.5  
3.6  
3.7  
3.8  
3.9  
3.10 A/D Converter Result Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64  
Chapter 4  
Central Processor Unit (CPU)  
4.1  
4.2  
4.2.1  
4.2.2  
4.2.3  
4.2.4  
4.2.5  
4.2.6  
4.2.6.1  
4.2.6.2  
4.2.6.3  
4.2.6.4  
4.2.6.5  
4.2.6.6  
4.2.6.7  
4.2.6.8  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65  
CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65  
Accumulators A, B, and D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66  
Index Register X (IX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66  
Index Register Y (IY) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66  
Stack Pointer (SP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66  
Program Counter (PC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68  
Condition Code Register (CCR). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68  
Carry/Borrow (C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68  
Overflow (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68  
Zero (Z). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68  
Negative (N) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68  
Interrupt Mask (I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69  
Half Carry (H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69  
X Interrupt Mask (X) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69  
STOP Disable (S). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69  
M68HC11E Family Data Sheet, Rev. 5.1  
8
Freescale Semiconductor  
4.3  
4.4  
Data Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69  
Opcodes and Operands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70  
4.5  
Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70  
Immediate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70  
Direct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70  
Extended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71  
Indexed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71  
Inherent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71  
Relative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71  
4.5.1  
4.5.2  
4.5.3  
4.5.4  
4.5.5  
4.5.6  
4.6  
Instruction Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71  
Chapter 5  
Resets and Interrupts  
5.1  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79  
5.2  
Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79  
Power-On Reset (POR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79  
External Reset (RESET) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80  
Computer Operating Properly (COP) Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80  
Clock Monitor Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81  
System Configuration Options Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82  
Configuration Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83  
5.2.1  
5.2.2  
5.2.3  
5.2.4  
5.2.5  
5.2.6  
5.3  
Effects of Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83  
Central Processor Unit (CPU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83  
Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84  
Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84  
Real-Time Interrupt (RTI). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84  
Pulse Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84  
Computer Operating Properly (COP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84  
Serial Communications Interface (SCI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84  
Serial Peripheral Interface (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84  
Analog-to-Digital (A/D) Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85  
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85  
5.3.1  
5.3.2  
5.3.3  
5.3.4  
5.3.5  
5.3.6  
5.3.7  
5.3.8  
5.3.9  
5.3.10  
5.4  
5.4.1  
Reset and Interrupt Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85  
Highest Priority Interrupt and Miscellaneous Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86  
5.5  
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87  
Interrupt Recognition and Register Stacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88  
Non-Maskable Interrupt Request (XIRQ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89  
Illegal Opcode Trap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89  
Software Interrupt (SWI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
Maskable Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
Reset and Interrupt Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
5.5.1  
5.5.2  
5.5.3  
5.5.4  
5.5.5  
5.5.6  
5.6  
5.6.1  
5.6.2  
Low-Power Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
9
Table of Contents  
Chapter 6  
Parallel Input/Output (I/O) Ports  
6.1  
6.2  
6.3  
6.4  
6.5  
6.6  
6.7  
6.8  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97  
Port A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98  
Port B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99  
Port C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99  
Port D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100  
Port E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101  
Handshake Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101  
Parallel I/O Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102  
Chapter 7  
Serial Communications Interface (SCI)  
7.1  
7.2  
7.3  
7.4  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105  
Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105  
Transmit Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105  
Receive Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107  
Wakeup Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107  
Idle-Line Wakeup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107  
Address-Mark Wakeup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109  
SCI Error Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109  
SCI Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109  
Serial Communications Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110  
Serial Communications Control Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110  
Serial Communications Control Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111  
Serial Communication Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112  
Baud Rate Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113  
7.5  
7.5.1  
7.5.2  
7.6  
7.7  
7.7.1  
7.7.2  
7.7.3  
7.7.4  
7.7.5  
7.8  
7.9  
Status Flags and Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116  
Receiver Flags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117  
Chapter 8  
Serial Peripheral Interface (SPI)  
8.1  
8.2  
8.3  
8.4  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119  
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119  
SPI Transfer Formats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119  
Clock Phase and Polarity Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120  
8.5  
SPI Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121  
Master In/Slave Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121  
Master Out/Slave In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121  
Serial Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122  
Slave Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122  
8.5.1  
8.5.2  
8.5.3  
8.5.4  
8.6  
SPI System Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122  
8.7  
SPI Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123  
Serial Peripheral Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123  
Serial Peripheral Status Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124  
Serial Peripheral Data I/O Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125  
8.7.1  
8.7.2  
8.7.3  
M68HC11E Family Data Sheet, Rev. 5.1  
10  
Freescale Semiconductor  
Chapter 9  
Timing Systems  
9.1  
9.2  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127  
Timer Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129  
9.3  
Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129  
Timer Control Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131  
Timer Input Capture Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131  
Timer Input Capture 4/Output Compare 5 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133  
9.3.1  
9.3.2  
9.3.3  
9.4  
Output Compare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133  
Timer Output Compare Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134  
Timer Compare Force Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135  
Output Compare Mask Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136  
Output Compare Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136  
Timer Counter Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137  
Timer Control Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137  
Timer Interrupt Mask 1 Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138  
Timer Interrupt Flag 1 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138  
Timer Interrupt Mask 2 Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139  
Timer Interrupt Flag Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140  
9.4.1  
9.4.2  
9.4.3  
9.4.4  
9.4.5  
9.4.6  
9.4.7  
9.4.8  
9.4.9  
9.4.10  
9.5  
Real-Time Interrupt (RTI). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140  
Timer Interrupt Mask Register 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141  
Timer Interrupt Flag Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142  
Pulse Accumulator Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142  
9.5.1  
9.5.2  
9.5.3  
9.6  
Computer Operating Properly (COP) Watchdog Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . 143  
9.7  
Pulse Accumulator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143  
Pulse Accumulator Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145  
Pulse Accumulator Count Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146  
Pulse Accumulator Status and Interrupt Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146  
9.7.1  
9.7.2  
9.7.3  
Chapter 10  
Electrical Characteristics  
10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149  
10.2 Maximum Ratings for Standard and Extended Voltage Devices . . . . . . . . . . . . . . . . . . . . . . . 149  
10.3 Functional Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150  
10.4 Thermal Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150  
10.5 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151  
10.6 Supply Currents and Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152  
10.7 MC68L11E9/E20 DC Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153  
10.8 MC68L11E9/E20 Supply Currents and Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . 154  
10.9 Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156  
10.10 MC68L11E9/E20 Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157  
10.11 Peripheral Port Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162  
10.12 MC68L11E9/E20 Peripheral Port Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163  
10.13 Analog-to-Digital Converter Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166  
10.14 MC68L11E9/E20 Analog-to-Digital Converter Characteristics . . . . . . . . . . . . . . . . . . . . . . . . 167  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
11  
Table of Contents  
10.15 Expansion Bus Timing Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168  
10.16 MC68L11E9/E20 Expansion Bus Timing Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169  
10.17 Serial Peripheral Interface Timing Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171  
10.18 MC68L11E9/E20 Serial Peirpheral Interface Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 172  
10.19 EEPROM Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175  
10.20 MC68L11E9/E20 EEPROM Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175  
10.21 EPROM Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175  
Chapter 11  
Ordering Information and Mechanical Specifications  
11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177  
11.2 Standard Device Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177  
11.3 Custom ROM Device Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179  
11.4 Extended Voltage Device Ordering Information (3.0 Vdc to 5.5 Vdc) . . . . . . . . . . . . . . . . . . . 181  
11.5 52-Pin Plastic-Leaded Chip Carrier (Case 778). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182  
11.6 52-Pin Windowed Ceramic-Leaded Chip Carrier (Case 778B) . . . . . . . . . . . . . . . . . . . . . . . . 183  
11.7 64-Pin Quad Flat Pack (Case 840C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184  
11.8 52-Pin Thin Quad Flat Pack (Case 848D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185  
11.9 56-Pin Dual in-Line Package (Case 859). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186  
11.10 48-Pin Plastic DIP (Case 767) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186  
Appendix A  
Development Support  
A.1  
A.2  
A.3  
A.4  
A.5  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187  
M68HC11 E-Series Development Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187  
EVS — Evaluation System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187  
Modular Development System (MMDS11) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188  
SPGMR11 — Serial Programmer for M68HC11 MCUs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189  
Appendix B  
EVBU Schematic  
AN1060 — M68HC11 Bootstrap Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193  
EB184 — Enabling the Security Feature on the MC68HC711E9 Devices with PCbug11 on the  
M68HC711E9PGMR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229  
EB188 — Enabling the Security Feature on M68HC811E2 Devices  
with PCbug11 on the M68HC711E9PGMR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233  
EB296 — Programming MC68HC711E9 Devices with PCbug11  
and the M68HC11EVBU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237  
M68HC11E Family Data Sheet, Rev. 5.1  
12  
Freescale Semiconductor  
Chapter 1  
General Description  
1.1 Introduction  
This document contains a detailed description of the M68HC11 E series of 8-bit microcontroller units  
(MCUs). These MCUs all combine the M68HC11 central processor unit (CPU) with high-performance,  
on-chip peripherals.  
The E series is comprised of many devices with various configurations of:  
Random-access memory (RAM)  
Read-only memory (ROM)  
Erasable programmable read-only memory (EPROM)  
Electrically erasable programmable read-only memory (EEPROM)  
Several low-voltage devices are also available.  
With the exception of a few minor differences, the operation of all E-series MCUs is identical. A fully static  
design and high-density complementary metal-oxide semiconductor (HCMOS) fabrication process allow  
the E-series devices to operate at frequencies from 3 MHz to dc with very low power consumption.  
1.2 Features  
Features of the E-series devices include:  
M68HC11 CPU  
Power-saving stop and wait modes  
Low-voltage devices available (3.0–5.5 Vdc)  
0, 256, 512, or 768 bytes of on-chip RAM, data retained during standby  
0, 12, or 20 Kbytes of on-chip ROM or EPROM  
0, 512, or 2048 bytes of on-chip EEPROM with block protect for security  
2048 bytes of EEPROM with selectable base address in the MC68HC811E2  
Asynchronous non-return-to-zero (NRZ) serial communications interface (SCI)  
Additional baud rates available on MC68HC(7)11E20  
Synchronous serial peripheral interface (SPI)  
8-channel, 8-bit analog-to-digital (A/D) converter  
16-bit timer system:  
Three input capture (IC) channels  
Four output compare (OC) channels  
One additional channel, selectable as fourth IC or fifth OC  
8-bit pulse accumulator  
Real-time interrupt circuit  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
13  
General Description  
Computer operating properly (COP) watchdog system  
38 general-purpose input/output (I/O) pins:  
16 bidirectional I/O pins  
11 input-only pins  
11 output-only pins  
Several packaging options:  
52-pin plastic-leaded chip carrier (PLCC)  
52-pin windowed ceramic leaded chip carrier (CLCC)  
52-pin plastic thin quad flat pack, 10 mm x 10 mm (TQFP)  
64-pin quad flat pack (QFP)  
48-pin plastic dual in-line package (DIP), MC68HC811E2 only  
56-pin plastic shrink dual in-line package, .070-inch lead spacing (SDIP)  
1.3 Structure  
See Figure 1-1 for a functional diagram of the E-series MCUs. Differences among devices are noted in  
the table accompanying Figure 1-1.  
1.4 Pin Descriptions  
M68HC11 E-series MCUs are available packaged in:  
52-pin plastic-leaded chip carrier (PLCC)  
52-pin windowed ceramic leaded chip carrier (CLCC)  
52-pin plastic thin quad flat pack, 10 mm x 10 mm (TQFP)  
64-pin quad flat pack (QFP)  
48-pin plastic dual in-line package (DIP), MC68HC811E2 only  
56-pin plastic shrink dual in-line package, .070-inch lead spacing (SDIP)  
Most pins on these MCUs serve two or more functions, as described in the following paragraphs. Refer  
to Figure 1-2, Figure 1-3, Figure 1-4, Figure 1-5, and Figure 1-6 which show the M68HC11 E-series pin  
assignments for the PLCC/CLCC, QFP, TQFP, SDIP, and DIP packages.  
M68HC11E Family Data Sheet, Rev. 5.1  
14  
Freescale Semiconductor  
Pin Descriptions  
MODA/ MODB/  
LIR VSTBY  
XTAL EXTAL  
E
IRQ XIRQ/VPPE* RESET  
OSC  
INTERRUPT  
LOGIC  
MODE CONTROL  
ROM OR EPROM  
(SEE TABLE)  
CLOCK LOGIC  
TIMER  
SYSTEM  
EEPROM  
(SEE TABLE)  
M68HC11 CPU  
RAM  
(SEE TABLE)  
SERIAL  
COMMUNICATION  
SERIAL  
PERIPHERAL  
INTERFACE  
SPI  
BUS EXPANSION  
ADDRESS  
ADDRESS/DATA  
VDD  
VSS  
INTERFACE  
SCI  
VRH  
VRL  
STROBE AND HANDSHAKE  
PARALLEL I/O  
A/D CONVERTER  
CONTROL  
CONTROL  
PORT A  
PORT B  
PORT C  
PORT D  
PORT E  
DEVICE  
RAM  
ROM  
EPROM EEPROM  
MC68HC11E0  
MC68HC11E1  
MC68HC11E9  
MC68HC711E9  
MC68HC11E20  
MC68HC711E20  
MC68HC811E2  
512  
512  
512  
512  
768  
768  
256  
12 K  
20 K  
12 K  
20 K  
512  
512  
512  
512  
512  
2048  
* VPPE applies only to devices with EPROM/OTPROM.  
Figure 1-1. M68HC11 E-Series Block Diagram  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
15  
General Description  
46 PE5/AN5  
PE1/AN1  
45  
XTAL  
8
9
PC0/ADDR0/DATA0  
PC1/ADDR1/DATA1 10  
44 PE4/AN4  
43 PE0/AN0  
42 PB0/ADDR8  
11  
12  
13  
14  
15  
16  
PC2/ADDR2/DATA2  
PC3/ADDR3/DATA3  
PC4/ADDR4/DATA4  
PC5/ADDR5/DATA5  
PC6/ADDR6/DATA6  
PC7/ADDR7/DATA7  
PB1/ADDR9  
40 PB2/ADDR10  
41  
M68HC11 E SERIES  
PB3/ADDR11  
PB4/ADDR12  
39  
38  
37 PB5/ADDR13  
36 PB6/ADDR14  
RESET 17  
18  
19  
20  
* XIRQ/VPPE  
IRQ  
PB7/ADDR15  
35  
34 PA0/IC3  
PD0/RxD  
* VPPE applies only to devices with EPROM/OTPROM.  
Figure 1-2. Pin Assignments for 52-Pin PLCC and CLCC  
M68HC11E Family Data Sheet, Rev. 5.1  
16  
Freescale Semiconductor  
Pin Descriptions  
1
2
PA0/IC3  
NC  
NC  
48  
47  
46  
45  
44  
43  
42  
41  
40  
39  
38  
37  
36  
PD0/RxD  
IRQ  
NC  
3
(1)  
NC  
XIRQ/VPPE  
NC  
4
5
6
7
8
PB7/ADDR15  
PB6/ADDR14  
PB5/ADDR13  
PB4/ADDR12  
RESET  
PC7/ADDR7/DATA7  
PC6/ADDR6/DATA6  
PC5/ADDR5/DATA5  
PC4/ADDR4/DATA4  
PC3/ADDR3/DATA3  
PC2/ADDR2/DATA2  
PC1/ADDR1/DATA1  
NC  
M68HC11 E SERIES  
PB3/ADDR11  
PB2/ADDR10  
PB1/ADDR9  
PB0/ADDR8  
PE0/AN0  
9
10  
11  
12  
13  
14  
15  
16  
PE4/AN4  
35  
34  
33  
PE1/AN1  
PC0/ADDR0/DATA0  
XTAL  
PE5/AN5  
1. VPPE applies only to devices with EPROM/OTPROM.  
Figure 1-3. Pin Assignments for 64-Pin QFP  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
17  
General Description  
1
2
PA0/IC3  
PB7/ADDR15  
PB6/ADDR14  
PB5/ADDR13  
PB4/ADDR12  
PB3/ADDR11  
PB2/ADDR10  
PB1/ADDR9  
PB0/ADDR8  
PE0/AN0  
PD0/RxD  
IRQ  
39  
38  
37  
36  
35  
34  
33  
32  
31  
30  
29  
28  
27  
(1)  
3
XIRQ/VPPE  
RESET  
4
5
6
7
8
PC7/ADDR7/DATA7  
PC6/ADDR6/DATA6  
PC5/ADDR5/DATA5  
M68HC11 E SERIES  
PC4/ADDR4/DATA4  
PC3/ADDR3/DATA3  
PC2/ADDR2/DATA2  
PC1/ADDR1/DATA1  
PC0/ADDR0/DATA0  
XTAL  
9
10  
11  
12  
13  
PE4/AN4  
PE1/AN1  
PE5/AN5  
1. VPPE applies only to devices with EPROM/OTPROM.  
Figure 1-4. Pin Assignments for 52-Pin TQFP  
M68HC11E Family Data Sheet, Rev. 5.1  
18  
Freescale Semiconductor  
Pin Descriptions  
VSS  
EVSS  
56  
55  
54  
53  
52  
51  
50  
49  
48  
47  
46  
45  
44  
43  
42  
41  
40  
39  
38  
37  
36  
35  
34  
33  
32  
31  
30  
29  
1
2
3
4
5
6
7
8
MODB/VSTBY  
VRH  
MODA/LIR  
STRA/AS  
VRL  
PE7/AN7  
PE3/AN3  
PE6/AN6  
PE2/AN2  
PE5/AN5  
PE1/AN1  
PE4/AN4  
PE0/AN0  
PB0/ADDR8  
PB1/ADDR9  
PB2/ADDR10  
PB3/ADDR11  
PB4/ADDR12  
PB5/ADDR13  
PB6/ADDR14  
E
STRB/R/W  
EXTAL  
XTAL  
PC0/ADDR0/DATA0  
PC1/ADDR1/DATA1  
PC2/ADDR2/DATA2  
PC3/ADDR3/DATA3  
PC4/ADDR4/DATA4  
PC5/ADDR5/DATA5  
PC6/ADDR6/DATA6  
PC7/ADDR7/DATA7  
RESET  
9
10  
11  
12  
13  
14  
15  
16  
17  
M68HC11 E SERIES  
* XIRQ/VPPE  
18  
19  
20  
21  
IRQ  
PD0/RxD  
EVSS  
PB7/ADDR15  
PA0/IC3  
PA1/IC2  
PA2/IC1  
PD1/TxD  
PD2/MISO  
PD3/MOSI  
PD4/SCK  
PD5/SS  
VDD  
22  
23  
24  
25  
26  
27  
28  
PA3/OC5/IC4/OC1  
PA4/OC4/OC1  
PA5/OC3/OC1  
PA6/OC2/OC1  
PA7/PAI/OC1  
EVDD  
VSS  
* VPPE applies only to devices with EPROM/OTPROM.  
Figure 1-5. Pin Assignments for 56-Pin SDIP  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
19  
General Description  
PA7/PAI/OC1  
PA6/OC2/OC1  
PA5/OC3/OC1  
PA4/OC4/OC1  
PA3/OC5/IC4/OC1  
PA2/IC1  
48 VDD  
1
PD5/SS  
47  
2
46 PD4/SCK  
3
PD3/MOSI  
44 PD2/MISO  
PD1/TxD  
42 PD0/RxD  
IRQ  
40 XIRQ  
45  
4
5
43  
6
PA1/IC2  
7
PA0/IC3  
41  
8
PB7/ADDR15  
PB6/ADDR14  
PB5/ADDR13  
PB4/ADDR12  
PB3/ADDR11  
PB2/ADDR10  
PB1/ADDR9  
PB0/ADDR8  
PE0/AN0  
9
RESET  
39  
10  
11  
12  
13  
14  
15  
16  
17  
38 PC7/ADDR7/DATA7  
37 PC6/ADDR6/DATA6  
36 PC5/ADDR5/DATA5  
35 PC4/ADDR4/DATA4  
34 PC3/ADDR3/DATA3  
MC68HC811E2  
PC2/ADDR2/DATA2  
PC1/ADDR1/DATA1  
PC0/ADDR0/DATA0  
33  
32  
31  
PE1/AN1  
18  
19  
20  
21  
PE2/AN2  
30 XTAL  
PE3/AN3  
29 EXTAL  
28 STRB/R/W  
VRL  
VRH  
22  
23  
24  
27  
E
VSS  
26 STRA/AS  
25 MODA/LIR  
MODB/VSTBY  
Figure 1-6. Pin Assignments for 48-Pin DIP (MC68HC811E2)  
M68HC11E Family Data Sheet, Rev. 5.1  
20  
Freescale Semiconductor  
Pin Descriptions  
1.4.1 V and V  
DD  
SS  
Power is supplied to the MCU through VDD and VSS. VDD is the power supply, VSS is ground. The MCU  
operates from a single 5-volt (nominal) power supply. Low-voltage devices in the E series operate at  
3.0–5.5 volts.  
Very fast signal transitions occur on the MCU pins. The short rise and fall times place high, short duration  
current demands on the power supply. To prevent noise problems, provide good power supply bypassing  
at the MCU. Also, use bypass capacitors that have good  
high-frequency characteristics and situate them as close to the MCU as possible. Bypass requirements  
vary, depending on how heavily the MCU pins are loaded.  
V
V
DD  
DD  
2
4.7 kΩ  
IN  
1
TO RESET  
OF M68HC11  
RESET  
MC34(0/1)64  
GND  
3
Figure 1-7. External Reset Circuit  
V
V
DD  
DD  
IN  
4.7 kΩ  
TO RESET  
OF M68HC11  
RESET  
MC34064  
V
DD  
GND  
4.7 kΩ  
1.0 µF  
MANUAL  
RESET SWITCH  
4.7 kΩ  
IN  
RESET  
MC34164  
GND  
OPTIONAL POWER-ON DELAY AND MANUAL RESET SWITCH  
Figure 1-8. External Reset Circuit with Delay  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
21  
General Description  
1.4.2 RESET  
A bidirectional control signal, RESET, acts as an input to initialize the MCU to a known startup state. It  
also acts as an open-drain output to indicate that an internal failure has been detected in either the clock  
monitor or computer operating properly (COP) watchdog circuit. The CPU distinguishes between internal  
and external reset conditions by sensing whether the reset pin rises to a logic 1 in less than two E-clock  
cycles after a reset has occurred. See Figure 1-7 and Figure 1-8.  
CAUTION  
Do not connect an external resistor capacitor (RC) power-up delay circuit  
to the reset pin of M68HC11 devices because the circuit charge time  
constant can cause the device to misinterpret the type of reset that  
occurred.  
Because the CPU is not able to fetch and execute instructions properly when VDD falls below the minimum  
operating voltage level, reset must be controlled. A low-voltage inhibit (LVI) circuit is required primarily for  
protection of EEPROM contents. However, since the configuration register (CONFIG) value is read from  
the EEPROM, protection is required even if the EEPROM array is not being used.  
Presently, there are several economical ways to solve this problem. For example, two good external  
components for LVI reset are:  
1. The Seiko S0854HN (or other S805 series devices):  
a. Extremely low power (2 µA)  
a. TO-92 package  
a. Limited temperature range, –20°C to +70°C  
a. Available in various trip-point voltage ranges  
2. The Freescale MC34064:  
a. TO-92 or SO-8 package  
a. Draws about 300 µA  
a. Temperature range –40°C to 85°C  
a. Well controlled trip point  
a. Inexpensive  
Refer to Chapter 5 Resets and Interrupts for further information.  
1.4.3 Crystal Driver and External Clock Input (XTAL and EXTAL)  
These two pins provide the interface for either a crystal or a CMOS- compatible clock to control the  
internal clock generator circuitry. The frequency applied to these pins is four times higher than the desired  
E-clock rate.  
The XTAL pin must be left unterminated when an external CMOS- compatible clock input is connected to  
the EXTAL pin. The XTAL output is normally intended to drive only a crystal. Refer to Figure 1-9 and  
Figure 1-10.  
CAUTION  
In all cases, use caution around the oscillator pins. Load capacitances  
shown in the oscillator circuit are specified by the crystal manufacturer and  
should include all stray layout capacitances.  
M68HC11E Family Data Sheet, Rev. 5.1  
22  
Freescale Semiconductor  
Pin Descriptions  
CL  
EXTAL  
10 MΩ  
4 x E  
CRYSTAL  
MCU  
CL  
XTAL  
Figure 1-9. Common Parallel Resonant Crystal Connections  
4 x E  
CMOS-COMPATIBLE  
EXTERNAL OSCILLATOR  
EXTAL  
MCU  
XTAL  
NC  
Figure 1-10. External Oscillator Connections  
1.4.4 E-Clock Output (E)  
E is the output connection for the internally generated E clock. The signal from E is used as a timing  
reference. The frequency of the E-clock output is one fourth that of the input frequency at the XTAL and  
EXTAL pins. When E-clock output is low, an internal process is taking place. When it is high, data is being  
accessed.  
All clocks, including the E clock, are halted when the MCU is in stop mode. To reduce RFI emissions, the  
E-clock output of most E-series devices can be disabled while operating in single-chip modes.  
The E-clock signal is always enabled on the MC68HC811E2.  
1.4.5 Interrupt Request (IRQ)  
The IRQ input provides a means of applying asynchronous interrupt requests to the MCU. Either negative  
edge-sensitive triggering or level-sensitive triggering is program selectable (OPTION register). IRQ is  
always configured to level-sensitive triggering at reset. When using IRQ in a level-sensitive wired-OR  
configuration, connect an external pullup resistor, typically 4.7 k, to VDD  
.
1.4.6 Non-Maskable Interrupt (XIRQ/V  
)
PPE  
The XIRQ input provides a means of requesting a non-maskable interrupt after reset initialization. During  
reset, the X bit in the condition code register (CCR) is set and any interrupt is masked until MCU software  
enables it. Because the XIRQ input is level-sensitive, it can be connected to a multiple-source wired-OR  
network with an external pullup resistor to VDD. XIRQ is often used as a power loss detect interrupt.  
Whenever XIRQ or IRQ is used with multiple interrupt sources each source must drive the interrupt input  
with an open-drain type of driver to avoid contention between outputs.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
23  
General Description  
NOTE  
IRQ must be configured for level-sensitive operation if there is more than  
one source of IRQ interrupt.  
There should be a single pullup resistor near the MCU interrupt input pin (typically 4.7 k). There must  
also be an interlock mechanism at each interrupt source so that the source holds the interrupt line low  
until the MCU recognizes and acknowledges the interrupt request. If one or more interrupt sources are  
still pending after the MCU services a request, the interrupt line will still be held low and the MCU will be  
interrupted again as soon as the interrupt mask bit in the MCU is cleared (normally upon return from an  
interrupt). Refer to Chapter 5 Resets and Interrupts.  
VPPE is the input for the 12-volt nominal programming voltage required for EPROM/OTPROM  
programming. On devices without EPROM/OTPROM, this pin is only an XIRQ input.  
CAUTION  
During EPROM programming of the MC68HC711E9 device, the VPPE pin  
circuitry may latch-up and be damaged if the input current is not limited to  
10 mA. For more information please refer to MC68HC711E9 8-Bit  
Microcontroller Unit Mask Set Errata 3 (Freescale document order number  
68HC711E9MSE3.  
1.4.7 MODA and MODB (MODA/LIR and MODB/V  
)
STBY  
During reset, MODA and MODB select one of the four operating modes:  
Single-chip mode  
Expanded mode  
Test mode  
Bootstrap mode  
Refer to Chapter 2 Operating Modes and On-Chip Memory.  
After the operating mode has been selected, the load instruction register (LIR) pin provides an open-drain  
output to indicate that execution of an instruction has begun. A series of E-clock cycles occurs during  
execution of each instruction. The LIR signal goes low during the first E-clock cycle of each instruction  
(opcode fetch). This output is provided for assistance in program debugging.  
The VSTBY pin is used to input random-access memory (RAM) standby power. When the voltage on this  
pin is more than one MOS threshold (about 0.7 volts) above the VDD voltage, the internal RAM and part  
of the reset logic are powered from this signal rather than the VDD input. This allows RAM contents to be  
retained without VDD power applied to the MCU. Reset must be driven low before VDD is removed and  
must remain low until VDD has been restored to a valid level.  
1.4.8 V and V  
RL  
RH  
These two inputs provide the reference voltages for the analog-to-digital (A/D) converter circuitry:  
V
RL is the low reference, typically 0 Vdc.  
RH is the high reference.  
V
For proper A/D converter operation:  
VRH should be at least 3 Vdc greater than VRL.  
RL and VRH should be between VSS and VDD  
V
.
M68HC11E Family Data Sheet, Rev. 5.1  
24  
Freescale Semiconductor  
Pin Descriptions  
1.4.9 STRA/AS  
The strobe A (STRA) and address strobe (AS) pin performs either of two separate functions, depending  
on the operating mode:  
In single-chip mode, STRA performs an input handshake (strobe input) function.  
In the expanded multiplexed mode, AS provides an address strobe function.  
AS can be used to demultiplex the address and data signals at port C. Refer to Chapter 2 Operating  
Modes and On-Chip Memory.  
1.4.10 STRB/R/W  
The strobe B (STRB) and read/write (R/W) pin act as either an output strobe or as a data bus direction  
indicator, depending on the operating mode.  
In single-chip operating mode, STRB acts as a programmable strobe for handshake with other parallel  
devices. Refer to Chapter 6 Parallel Input/Output (I/O) Ports for further information.  
In expanded multiplexed operating mode, R/W is used to indicate the direction of transfers on the external  
data bus. A low on the R/W pin indicates data is being written to the external data bus. A high on this pin  
indicates that a read cycle is in progress. R/W stays low during consecutive data bus write cycles, such  
as a double-byte store. It is possible for data to be driven out of port C, if internal read visibility (IRV) is  
enabled and an internal address is read, even though R/W is in a high-impedance state. Refer to  
Chapter 2 Operating Modes and On-Chip Memory for more information about IRVNE (internal read  
visibility not E).  
1.4.11 Port Signals  
Port pins have different functions in different operating modes. Pin functions for port A, port D, and port  
E are independent of operating modes. Port B and port C, however, are affected by operating mode. Port  
B provides eight general-purpose output signals in single-chip operating modes. When the microcontroller  
is in expanded multiplexed operating mode, port B pins are the eight high-order address lines.  
Port C provides eight general-purpose input/output signals when the MCU is in the single-chip operating  
mode. When the microcontroller is in the expanded multiplexed operating mode, port C pins are a  
multiplexed address/data bus.  
Refer to Table 1-1 for a functional description of the 40 port signals within different operating modes.  
Terminate unused inputs and input/output (I/O) pins configured as inputs high or low.  
1.4.12 Port A  
In all operating modes, port A can be configured for three timer input capture (IC) functions and four timer  
output compare (OC) functions. An additional pin can be configured as either the fourth IC or the fifth OC.  
Any port A pin that is not currently being used for a timer function can be used as either a general-purpose  
input or output line. Only port A pins PA7 and PA3 have an associated data direction control bit that allows  
the pin to be selectively configured as input or output. Bits DDRA7 and DDRA3 located in PACTL register  
control data direction for PA7 and PA3, respectively. All other port A pins are fixed as either input or  
output.  
PA7 can function as general-purpose I/O or as timer output compare for OC1. PA7 is also the input to the  
pulse accumulator, even while functioning as a general-purpose I/O or an OC1 output.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
25  
General Description  
Table 1-1. Port Signal Functions  
Single-Chip and  
Bootstrap Modes  
Expanded and  
Test Modes  
Port/Bit  
PA0  
PA1  
PA2  
PA3  
PA4  
PA5  
PA6  
PA7  
PB0  
PB1  
PB2  
PB3  
PB4  
PB5  
PB6  
PB7  
PC0  
PC1  
PC2  
PC3  
PC4  
PC5  
PC6  
PC7  
PD0  
PD1  
PD2  
PD3  
PD4  
PD5  
PA0/IC3  
PA1/IC2  
PA2/IC1  
PA3/OC5/IC4/OC1  
PA4/OC4/OC1  
PA5/OC3/OC1  
PA6/OC2/OC1  
PA7/PAI/OC1  
PB0  
ADDR8  
ADDR9  
PB1  
PB2  
ADDR10  
PB3  
ADDR11  
PB4  
ADDR12  
PB5  
ADDR13  
PB6  
ADDR14  
PB7  
ADDR15  
PC0  
ADDR0/DATA0  
ADDR1/DATA1  
ADDR2/DATA2  
ADDR3/DATA3  
ADDR4/DATA4  
ADDR5/DATA5  
ADDR6/DATA6  
ADDR7/DATA7  
PC1  
PC2  
PC3  
PC4  
PC5  
PC6  
PC7  
PD0/RxD  
PD1/TxD  
PD2/MISO  
PD3/MOSI  
PD4/SCK  
PD5/SS  
STRA  
AS  
STRB  
R/W  
PE0  
PE1  
PE2  
PE3  
PE4  
PE5  
PE6  
PE7  
PE0/AN0  
PE1/AN1  
PE3/AN2  
PE3/AN3  
PE4/AN4  
PE5/AN5  
PE6/AN6  
PE7/AN7  
M68HC11E Family Data Sheet, Rev. 5.1  
26  
Freescale Semiconductor  
Pin Descriptions  
PA6–PA4 serve as either general-purpose outputs, timer input captures, or timer output compare 2–4. In  
addition, PA6–PA4 can be controlled by OC1.  
PA3 can be a general-purpose I/O pin or a timer IC/OC pin. Timer functions associated with this pin  
include OC1 and IC4/OC5. IC4/OC5 is software selectable as either a fourth input capture or a fifth output  
compare. PA3 can also be configured to allow OC1 edges to trigger IC4 captures.  
PA2–PA0 serve as general-purpose inputs or as IC1–IC3.  
PORTA can be read at any time. Reads of pins configured as inputs return the logic level present on the  
pin. Pins configured as outputs return the logic level present at the pin driver input. If written, PORTA  
stores the data in an internal latch, bits 7 and 3. It drives the pins only if they are configured as outputs.  
Writes to PORTA do not change the pin state when pins are configured for timer input captures or output  
compares. Refer to Chapter 6 Parallel Input/Output (I/O) Ports.  
1.4.13 Port B  
During single-chip operating modes, all port B pins are general-purpose output pins. During MCU reads  
of this port, the level sensed at the input side of the port B output drivers is read. Port B can also be used  
in simple strobed output mode. In this mode, an output pulse appears at the STRB signal each time data  
is written to port B.  
In expanded multiplexed operating modes, all of the port B pins act as high order address output signals.  
During each MCU cycle, bits 15–8 of the address bus are output on the PB7–PB0 pins. The PORTB  
register is treated as an external address in expanded modes.  
1.4.14 Port C  
While in single-chip operating modes, all port C pins are general-purpose I/O pins. Port C inputs can be  
latched into an alternate PORTCL register by providing an input transition to the STRA signal. Port C can  
also be used in full handshake modes of parallel I/O where the STRA input and STRB output act as  
handshake control lines.  
When in expanded multiplexed modes, all port C pins are configured as multiplexed address/data signals.  
During the address portion of each MCU cycle, bits 7–0 of the address are output on the PC7–PC0 pins.  
During the data portion of each MCU cycle (E high), PC7–PC0 are bidirectional data signals,  
DATA7–DATA0. The direction of data at the port C pins is indicated by the R/W signal.  
The CWOM control bit in the PIOC register disables the port C P-channel output driver. CWOM  
simultaneously affects all eight bits of port C. Because the N-channel driver is not affected by CWOM,  
setting CWOM causes port C to become an open-drain type output port suitable for wired-OR operation.  
In wired-OR mode:  
When a port C bit is at logic level 0, it is driven low by the N-channel driver.  
When a port C bit is at logic level 1, the associated pin has high-impedance, as neither the  
N-channel nor the P-channel devices are active.  
It is customary to have an external pullup resistor on lines that are driven by open-drain devices. Port C  
can only be configured for wired-OR operation when the MCU is in single-chip mode. Refer to Chapter 6  
Parallel Input/Output (I/O) Ports for additional information about port C functions.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
27  
General Description  
1.4.15 Port D  
Pins PD5–PD0 can be used for general-purpose I/O signals. These pins alternately serve as the serial  
communication interface (SCI) and serial peripheral interface (SPI) signals when those subsystems are  
enabled.  
PD0 is the receive data input (RxD) signal for the SCI.  
PD1 is the transmit data output (TxD) signal for the SCI.  
PD5–PD2 are dedicated to the SPI:  
PD2 is the master in/slave out (MISO) signal.  
PD3 is the master out/slave in (MOSI) signal.  
PD4 is the serial clock (SCK) signal.  
PD5 is the slave select (SS) input.  
1.4.16 Port E  
Use port E for general-purpose or analog-to-digital (A/D) inputs.  
CAUTION  
If high accuracy is required for A/D conversions, avoid reading port E during  
sampling, as small disturbances can reduce the accuracy of that result.  
M68HC11E Family Data Sheet, Rev. 5.1  
28  
Freescale Semiconductor  
Chapter 2  
Operating Modes and On-Chip Memory  
2.1 Introduction  
This section contains information about the operating modes and the on-chip memory for M68HC11  
E-series MCUs. Except for a few minor differences, operation is identical for all devices in the E series.  
Differences are noted where necessary.  
2.2 Operating Modes  
The values of the mode select inputs MODB and MODA during reset determine the operating mode.  
Single-chip and expanded multiplexed are the normal modes.  
In single-chip mode only on-chip memory is available.  
Expanded mode, however, allows access to external memory.  
Each of the two normal modes is paired with a special mode:  
Bootstrap, a variation of the single-chip mode, is a special mode that executes a bootloader  
program in an internal bootstrap ROM.  
Test is a special mode that allows privileged access to internal resources.  
2.2.1 Single-Chip Mode  
In single-chip mode, ports B and C and strobe pins A (STRA) and B (STRB) are available for  
general-purpose parallel input/output (I/O). In this mode, all software needed to control the MCU is  
contained in internal resources. If present, read-only memory (ROM) and/or erasable, programmable  
read-only memory (EPROM) will always be enabled out of reset, ensuring that the reset and interrupt  
vectors will be available at locations $FFC0–$FFFF.  
NOTE  
For the MC68HC811E2, the vector locations are the same; however, they  
are contained in the 2048-byte EEPROM array.  
2.2.2 Expanded Mode  
In expanded operating mode, the MCU can access the full 64-Kbyte address space. The space includes:  
The same on-chip memory addresses used for single-chip mode  
Addresses for external peripherals and memory devices  
The expansion bus is made up of ports B and C, and control signals AS (address strobe) and R/W  
(read/write). R/W and AS allow the low-order address and the 8-bit data bus to be multiplexed on the  
same pins. During the first half of each bus cycle address information is present. During the second half  
of each bus cycle the pins become the bidirectional data bus. AS is an active-high latch enable signal for  
an external address latch. Address information is allowed through the transparent latch while AS is high  
and is latched when AS drives low.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
29  
Operating Modes and On-Chip Memory  
The address, R/W, and AS signals are active and valid for all bus cycles, including accesses to internal  
memory locations. The E clock is used to enable external devices to drive data onto the internal data bus  
during the second half of a read bus cycle (E clock high). R/W controls the direction of data transfers. R/W  
drives low when data is being written to the internal data bus. R/W will remain low during consecutive data  
bus write cycles, such as when a double-byte store occurs.  
Refer to Figure 2-1.  
NOTE  
The write enable signal for an external memory is the NAND of the E clock  
and the inverted R/W signal.  
PB7  
PB6  
PB5  
PB4  
PB3  
PB2  
PB1  
PB0  
ADDR15  
ADDR14  
ADDR13  
ADDR12  
ADDR11  
ADDR10  
ADDR9  
ADDR8  
HC373  
Q1  
PC7  
PC6  
PC5  
PC4  
PC3  
PC2  
PC1  
PC0  
D1  
D2  
D3  
D4  
D5  
D6  
D7  
D8  
ADDR7  
ADDR6  
ADDR5  
ADDR4  
ADDR3  
ADDR2  
ADDR1  
ADDR0  
Q2  
Q3  
Q4  
Q5  
Q6  
Q7  
Q8  
LE  
OE  
AS  
R/W  
E
WE  
OE  
DATA7  
DATA6  
DATA5  
DATA4  
DATA3  
DATA2  
DATA1  
DATA0  
MCU  
Figure 2-1. Address/Data Demultiplexing  
2.2.3 Test Mode  
Test mode, a variation of the expanded mode, is primarily used during Freescale’s internal production  
testing; however, it is accessible for programming the configuration (CONFIG) register, programming  
calibration data into electrically erasable, programmable read-only memory (EEPROM), and supporting  
emulation and debugging during development.  
2.2.4 Bootstrap Mode  
When the MCU is reset in special bootstrap mode, a small on-chip read-only memory (ROM) is enabled  
at address $BF00–$BFFF. The ROM contains a bootloader program and a special set of interrupt and  
reset vectors. The MCU fetches the reset vector, then executes the bootloader.  
Bootstrap mode is a special variation of the single-chip mode. Bootstrap mode allows special-purpose  
programs to be entered into internal random-access memory (RAM). When bootstrap mode is selected  
at reset, a small bootstrap ROM becomes present in the memory map. Reset and interrupt vectors are  
M68HC11E Family Data Sheet, Rev. 5.1  
30  
Freescale Semiconductor  
Memory Map  
located in this ROM at $BFC0–$BFFF. The bootstrap ROM contains a small program which initializes the  
serial communications interface (SCI) and allows the user to download a program into on-chip RAM. The  
size of the downloaded program can be as large as the size of the on-chip RAM. After a 4-character delay,  
or after receiving the character for the highest address in RAM, control passes to the loaded program at  
$0000. Refer to Figure 2-2, Figure 2-3, Figure 2-4, Figure 2-5, and Figure 2-6.  
Use of an external pullup resistor is required when using the SCI transmitter pin because port D pins are  
configured for wired-OR operation by the bootloader. In bootstrap mode, the interrupt vectors are directed  
to RAM. This allows the use of interrupts through a jump table. Refer to the application note AN1060  
entitled M68HC11 Bootstrap Mode, that is included in this data book.  
2.3 Memory Map  
The operating mode determines memory mapping and whether external addresses can be accessed.  
Refer to Figure 2-2, Figure 2-3, Figure 2-4, Figure 2-5, and Figure 2-6, which illustrate the memory maps  
for each of the three families comprising the M68HC11 E series of MCUs.  
Memory locations for on-chip resources are the same for both expanded and single-chip modes. Control  
bits in the configuration (CONFIG) register allow EPROM and EEPROM (if present) to be disabled from  
the memory map. The RAM is mapped to $0000 after reset. It can be placed at any 4-Kbyte boundary  
($x000) by writing an appropriate value to the RAM and I/O map register (INIT). The 64-byte register block  
is mapped to $1000 after reset and also can be placed at any 4-Kbyte boundary ($x000) by writing an  
appropriate value to the INIT register. If RAM and registers are mapped to the same boundary, the first  
64 bytes of RAM will be inaccessible.  
Refer to Figure 2-7, which details the MCU register and control bit assignments. Reset states shown are  
for single-chip mode only.  
$0000  
0000  
512 BYTES RAM  
EXT  
EXT  
01FF  
1000  
$1000  
64-BYTE REGISTER BLOCK  
103F  
$B600  
$D000  
$FFFF  
EXT  
EXT  
BOOT  
ROM  
BFC0  
BFFF  
BF00  
BFFF  
SPECIAL MODES  
INTERRUPT  
VECTORS  
NORMAL  
MODES  
INTERRUPT  
VECTORS  
FFC0  
FFFF  
EXPANDED  
BOOTSTRAP  
SPECIAL  
TEST  
Figure 2-2. Memory Map for MC68HC11E0  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
31  
Operating Modes and On-Chip Memory  
0000  
$0000  
512 BYTES RAM  
EXT  
EXT  
EXT  
01FF  
1000  
$1000  
64-BYTE REGISTER BLOCK  
103F  
EXT  
B600  
512 BYTES EEPROM  
$B600  
B7FF  
BF00  
BOOT  
ROM  
BFC0  
BFFF  
SPECIAL MODES  
INTERRUPT  
VECTORS  
EXT  
EXT  
BFFF  
$D000  
NORMAL  
MODES  
INTERRUPT  
VECTORS  
FFC0  
FFFF  
$FFFF  
EXPANDED  
BOOTSTRAP  
SPECIAL  
TEST  
Figure 2-3. Memory Map for MC68HC11E1  
0000  
$0000  
$1000  
512 BYTES RAM  
EXT  
EXT  
EXT  
01FF  
1000  
64-BYTE REGISTER BLOCK  
103F  
EXT  
B600  
512 BYTES EEPROM  
$B600  
$D000  
$FFFF  
B7FF  
BF00  
BOOT  
ROM  
BFC0  
BFFF  
SPECIAL MODES  
INTERRUPT  
VECTORS  
EXT  
EXT  
BFFF  
D000  
12 KBYTES ROM/EPROM  
FFC0  
NORMAL  
MODES  
INTERRUPT  
VECTORS  
FFFF  
FFFF  
SINGLE  
CHIP  
EXPANDED  
BOOTSTRAP  
SPECIAL  
TEST  
Figure 2-4. Memory Map for MC68HC(7)11E9  
M68HC11E Family Data Sheet, Rev. 5.1  
32  
Freescale Semiconductor  
Memory Map  
0000  
$0000  
$1000  
768 BYTES RAM  
EXT  
EXT  
EXT  
EXT  
02FF  
1000  
64-BYTE REGISTER BLOCK  
103F  
9000  
8 KBYTES ROM/EPROM *  
512 BYTES EEPROM  
BOOT  
$9000  
$B600  
AFFF  
B600  
EXT  
EXT  
EXT  
EXT  
B7FF  
BF00  
BFC0  
SPECIAL MODES  
INTERRUPT  
VECTORS  
ROM  
BFFF  
BFFF  
D000  
$D000  
12 KBYTES ROM/EPROM *  
FFC0  
NORMAL  
MODES  
INTERRUPT  
FFFF  
FFFF VECTORS  
$FFFF  
SINGLE  
CHIP  
EXPANDED  
BOOTSTRAP  
SPECIAL  
TEST  
* 20 Kbytes ROM/EPROM are contained in two segments of 8 Kbytes and 12 Kbytes each.  
Figure 2-5. Memory Map for MC68HC(7)11E20  
$0000  
$1000  
0000  
00FF  
256 BYTES RAM  
EXT  
EXT  
1000  
103F  
64-BYTE REGISTER BLOCK  
EXT  
EXT  
BOOT  
ROM  
BFC0  
BFFF  
SPECIAL MODES  
INTERRUPT  
VECTORS  
BF00  
BFFF  
2048 BYTES EEPROM  
$F800  
$FFFF  
F800  
FFFF  
NORMAL  
MODES  
INTERRUPT  
FFC0  
FFFF VECTORS  
SINGLE  
CHIP  
EXPANDED  
BOOTSTRAP  
SPECIAL  
TEST  
Figure 2-6. Memory Map for MC68HC811E2  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
33  
Operating Modes and On-Chip Memory  
Addr.  
$1000  
$1001  
Register Name  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
(PORTA) Write:  
Port A Data Register  
PA7  
PA6  
PA5  
PA4  
PA3  
PA2  
PA1  
PA0  
See page 98.  
Reset:  
I
0
0
0
I
I
I
I
Reserved  
R
R
R
R
R
R
R
R
Read:  
Parallel I/O Control Register  
STAF  
0
STAI  
0
CWOM  
0
HNDS  
0
OIN  
0
PLS  
U
EGA  
1
INVB  
1
$1002  
$1003  
$1004  
(PIOC) Write:  
See page 102.  
Reset:  
Read:  
Port C Data Register  
PC7  
PC6  
PC5  
PC4  
PC3  
PC2  
PC1  
PC0  
(PORTC) Write:  
See page 99.  
Reset:  
Read:  
Indeterminate after reset  
Port B Data Register  
PB7  
0
PB6  
0
PB5  
0
PB4  
0
PB3  
0
PB2  
0
PB1  
0
PB0  
0
(PORTB) Write:  
See page 99.  
Reset:  
Read:  
Port C Latched Register  
PCL7  
PCL6  
PCL5  
PCL4  
PCL3  
PCL2  
PCL1  
PCL0  
$1005  
$1006  
(PORTCL) Write:  
See page 99.  
Reset:  
Indeterminate after reset  
Reserved  
R
R
R
R
R
R
R
R
Read:  
Port C Data Direction Register  
(DDRC) Write:  
DDRC7 DDRC6  
DDRC5  
DDRC4  
DDRC3  
DDRC2  
DDRC1 DDRC0  
$1007  
$1008  
$1009  
$100A  
$100B  
$100C  
See page 100.  
Reset:  
Read:  
0
0
0
0
0
PD5  
I
0
PD4  
I
0
PD3  
I
0
PD2  
I
0
PD1  
I
0
PD0  
I
Port D Data Register  
(PORTD) Write:  
See page 100.  
Reset:  
Read:  
U
U
Port D Data Direction Register  
DDRD5  
0
DDRD4  
0
DDRD3  
0
DDRD2  
0
DDRD1 DDRD0  
(DDRD) Write:  
See page 100.  
Reset:  
Read:  
0
0
0
0
Port E Data Register  
PE7  
PE6  
PE5  
PE4  
PE3  
PE2  
PE1  
PE0  
(PORTE) Write:  
See page 101.  
Reset:  
Read:  
Indeterminate after reset  
Timer Compare Force Register  
FOC1  
0
FOC2  
0
FOC3  
FOC4  
0
FOC5  
0
(CFORC) Write:  
See page 135.  
Reset:  
Read:  
0
OC1M5  
0
0
0
0
0
0
0
Output Compare 1 Mask Register  
OC1M7 OC1M6  
OC1M4  
OC1M3  
(OC1M) Write:  
See page 136.  
Reset:  
0
0
0
0
= Unimplemented  
I = Indeterminate after reset  
R
= Reserved  
U = Unaffected  
Figure 2-7. Register and Control Bit Assignments (Sheet 1 of 6)  
M68HC11E Family Data Sheet, Rev. 5.1  
34  
Freescale Semiconductor  
Memory Map  
Addr.  
Register Name  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Output Compare 1 Data Register  
OC1D7 OC1D6  
OC1D5  
OC1D4  
OC1D3  
$100D  
(OC1D) Write:  
See page 136.  
Reset:  
Read: Bit 15  
(TCNTH) Write:  
0
0
0
0
0
0
0
0
Bit 14  
Bit 13  
Bit 12  
Bit 11  
Bit 10  
Bit 9  
Bit 8  
Timer Counter Register High  
$100E  
$100F  
$1010  
$1011  
$1012  
$1013  
$1014  
$1015  
$1016  
$1017  
$1018  
See page 137.  
Reset:  
0
0
0
0
0
0
0
0
Read: Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
Timer Counter Register Low  
(TCNTL) Write:  
See page 137.  
Reset:  
Read:  
0
0
0
0
0
0
0
0
Timer Input Capture 1 Register  
Bit 15  
Bit 14  
Bit 13  
Bit 12  
Bit 11  
Bit 10  
Bit 9  
Bit 8  
High (TIC1H) Write:  
See page 132.  
Reset:  
Indeterminate after reset  
Bit 4 Bit 3  
Indeterminate after reset  
Bit 12 Bit 11  
Indeterminate after reset  
Bit 4 Bit 3  
Indeterminate after reset  
Bit 12 Bit 11  
Indeterminate after reset  
Bit 4 Bit 3  
Indeterminate after reset  
Read:  
Timer Input Capture 1 Register  
Bit 7  
Bit 15  
Bit 7  
Bit 6  
Bit 14  
Bit 6  
Bit 5  
Bit 13  
Bit 5  
Bit 2  
Bit 10  
Bit 2  
Bit 1  
Bit 9  
Bit 1  
Bit 9  
Bit 1  
Bit 0  
Bit 8  
Bit 0  
Bit 8  
Bit 0  
Low (TIC1L) Write:  
See page 132.  
Reset:  
Read:  
Timer Input Capture 2 Register  
High (TIC2H) Write:  
See page 132.  
Reset:  
Read:  
TImer Input Capture 2 Register  
Low (TIC2L) Write:  
See page 132.  
Reset:  
Read:  
Timer Input Capture 3 Register  
Bit 15  
Bit 7  
Bit 14  
Bit 6  
Bit 13  
Bit 5  
Bit 10  
Bit 2  
High (TIC3H) Write:  
See page 132.  
Reset:  
Read:  
Timer Input Capture 3 Register  
Low (TIC3L) Write:  
See page 132.  
Reset:  
Read:  
Timer Output Compare 1 Register  
Bit 15  
1
Bit 14  
1
Bit 13  
1
Bit 12  
1
Bit 11  
1
Bit 10  
1
Bit 9  
1
Bit 8  
1
High (TOC1H) Write:  
See page 134.  
Reset:  
Read:  
Timer Output Compare 1 Register  
Bit 7  
1
Bit 6  
1
Bit 5  
1
Bit 4  
1
Bit 3  
1
Bit 2  
1
Bit 1  
1
Bit 0  
1
Low (TOC1L) Write:  
See page 134.  
Reset:  
Read:  
Timer Output Compare 2 Register  
Bit 15  
Bit 14  
Bit 13  
Bit 12  
Bit 11  
Bit 10  
Bit 9  
Bit 8  
1
High (TOC2H) Write:  
See page 134.  
Reset:  
1
1
1
1
1
1
1
= Unimplemented  
I = Indeterminate after reset  
R
= Reserved  
U = Unaffected  
Figure 2-7. Register and Control Bit Assignments (Sheet 2 of 6)  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
35  
Operating Modes and On-Chip Memory  
Addr.  
Register Name  
Bit 7  
Bit 7  
1
6
Bit 6  
1
5
Bit 5  
1
4
Bit 4  
1
3
Bit 3  
1
2
Bit 2  
1
1
Bit 1  
1
Bit 0  
Bit 0  
1
Read:  
Timer Output Compare 2 Register  
$1019  
Low (TOC2L) Write:  
See page 134.  
Reset:  
Read:  
Timer Output Compare 3 Register  
Bit 15  
1
Bit 14  
1
Bit 13  
1
Bit 12  
1
Bit 11  
1
Bit 10  
1
Bit 9  
1
Bit 8  
1
$101A  
$101B  
$101C  
$101D  
$101E  
$101F  
$1020  
$1021  
$1022  
$1023  
$1024  
High (TOC3H) Write:  
See page 135.  
Reset:  
Read:  
Timer Output Compare 3 Register  
Bit 7  
1
Bit 6  
1
Bit 5  
1
Bit 4  
1
Bit 3  
1
Bit 2  
1
Bit 1  
1
Bit 0  
1
Low (TOC3L) Write:  
See page 135.  
Reset:  
Read:  
Timer Output Compare 4 Register  
Bit 15  
1
Bit 14  
1
Bit 13  
1
Bit 12  
1
Bit 11  
1
Bit 10  
1
Bit 9  
1
Bit 8  
1
High (TOC4H) Write:  
See page 135.  
Reset:  
Read:  
Timer Output Compare 4 Register  
Bit 7  
1
Bit 6  
1
Bit 5  
1
Bit 4  
1
Bit 3  
1
Bit 2  
1
Bit 1  
1
Bit 0  
1
Low (TOC4L) Write:  
See page 135.  
Reset:  
Read:  
Timer Input Capture 4/Output  
Compare 5 Register High Write:  
Bit 15  
1
Bit 14  
1
Bit 13  
1
Bit 12  
1
Bit 11  
1
Bit 10  
1
Bit 9  
1
Bit 8  
1
(TI4/O5) See page 133.  
Reset:  
Read:  
Timer Input Capture 4/Output  
Compare 5 Register Low Write:  
Bit 7  
1
Bit 6  
1
Bit 5  
1
Bit 4  
1
Bit 3  
1
Bit 2  
1
Bit 1  
1
Bit 0  
1
(TI4/O5) See page 133.  
Reset:  
Read:  
Timer Control Register 1  
OM2  
0
OL2  
0
OM3  
0
OL3  
0
OM4  
0
OL4  
0
OM5  
0
OL5  
0
(TCTL1) Write:  
See page 137.  
Reset:  
Read:  
Timer Control Register 2  
EDG4B EDG4A  
EDG1B  
0
EDG1A  
0
EDG2B  
0
EDG2A  
0
EDG3B EDG3A  
(TCTL2) Write:  
See page 131.  
Reset:  
0
OC1I  
0
0
OC2I  
0
0
IC2I  
0
0
IC3I  
0
Read:  
Timer Interrupt Mask 1 Register  
OC3I  
0
OC4I  
0
I4/O5I  
0
IC1I  
0
(TMSK1) Write:  
See page 138.  
Reset:  
Read:  
Timer Interrupt Flag 1  
OC1F  
0
OC2F  
0
OC3F  
0
OC4F  
0
I4/O5F  
0
IC1F  
0
IC2F  
0
IC3F  
0
(TFLG1) Write:  
See page 138.  
Reset:  
Read:  
Timer Interrupt Mask 2 Register  
TOI  
0
RTII  
0
PAOVI  
0
PAII  
PR1  
0
PR0  
0
(TMSK2) Write:  
See page 139.  
Reset:  
0
0
0
= Unimplemented  
I = Indeterminate after reset  
R
= Reserved  
U = Unaffected  
Figure 2-7. Register and Control Bit Assignments (Sheet 3 of 6)  
M68HC11E Family Data Sheet, Rev. 5.1  
36  
Freescale Semiconductor  
Memory Map  
Addr.  
Register Name  
Bit 7  
TOF  
0
6
RTIF  
0
5
PAOVF  
0
4
PAIF  
0
3
2
1
Bit 0  
Read:  
Timer Interrupt Flag 2  
$1025  
(TFLG2) Write:  
See page 142.  
Reset:  
Read:  
0
DDRA3  
0
0
0
0
Pulse Accumulator Control Regis-  
DDRA7  
0
PAEN  
0
PAMOD  
0
PEDGE  
0
I4/O5  
0
RTR1  
0
RTR0  
0
$1026  
$1027  
$1028  
$1029  
$102A  
$102B  
$102C  
$102D  
$102E  
ter (PACTL) Write:  
See page 142.  
Reset:  
Read:  
Pulse Accumulator Count Regis-  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
ter (PACNT) Write:  
See page 146.  
Reset:  
Indeterminate after reset  
Read:  
Serial Peripheral Control Register  
SPIE  
0
SPE  
0
DWOM  
0
MSTR  
0
CPOL  
0
CPHA  
1
SPR1  
U
SPR0  
U
(SPCR) Write:  
See page 123.  
Reset:  
Read:  
Serial Peripheral Status Register  
SPIF  
0
WCOL  
0
MODF  
0
(SPSR) Write:  
See page 124.  
Reset:  
Read:  
0
0
0
0
0
Serial Peripheral Data I/O Regis-  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
ter (SPDR) Write:  
See page 125.  
Reset:  
Indeterminate after reset  
Read:  
TCLR  
SCP2(1)  
SCP1  
0
SCP0  
RCKB  
SCR2  
U
SCR1  
U
SCR0  
U
Baud Rate Register  
(BAUD) Write:  
See page 113.  
Reset:  
Read:  
0
R8  
I
0
T8  
I
0
M
0
WAKE  
0
Serial Communications Control  
Register 1 (SCCR1) Write:  
See page 110.  
Reset:  
0
RIE  
0
0
0
RE  
0
0
RWU  
0
0
SBK  
0
Read:  
Serial Communications Control  
TIE  
0
TCIE  
0
ILIE  
0
TE  
0
Register 2 (SCCR2) Write:  
See page 111.  
Reset:  
Read:  
Serial Communications Status  
TDRE  
TC  
RDRF  
0
IDLE  
0
OR  
0
NF  
0
FE  
0
Register (SCSR) Write:  
See page 112.  
Reset:  
1
1
0
1. SCP2 adds ÷39 to SCI prescaler and is present only in MC68HC(7)11E20.  
Read:  
Serial Communications Data Reg-  
R7/T7  
R6/T6  
R5/T5  
R4/T4  
R3/T3  
R2/T2  
R1/T1  
R0/T0  
$102F  
$1030  
ister (SCDR) Write:  
See page 110.  
Reset:  
Indeterminate after reset  
Read: CCF  
Register (ADCTL) Write:  
See page 62.  
Analog-to-Digital Control Status  
SCAN  
MULT  
CD  
CC  
CB  
CA  
Reset:  
0
0
= Unimplemented  
I = Indeterminate after reset  
Indeterminate after reset  
= Reserved U = Unaffected  
R
Figure 2-7. Register and Control Bit Assignments (Sheet 4 of 6)  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
37  
Operating Modes and On-Chip Memory  
Addr.  
Register Name  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read: Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
Analog-to-Digital Results  
$1031  
Register 1 (ADR1) Write:  
See page 64.  
Reset:  
Indeterminate after reset  
Bit 4 Bit 3  
Read: Bit 7  
Bit 6  
Bit 6  
Bit 6  
Bit 5  
Bit 5  
Bit 5  
Bit 2  
Bit 2  
Bit 2  
Bit 1  
Bit 1  
Bit 1  
Bit 0  
Bit 0  
Bit 0  
Analog-to-Digital Results  
$1032  
$1033  
$1034  
$1035  
Register 2 (ADR2) Write:  
See page 64.  
Reset:  
Indeterminate after reset  
Bit 4 Bit 3  
Read: Bit 7  
Analog-to-Digital Results  
Register 3 (ADR3) Write:  
See page 64.  
Reset:  
Indeterminate after reset  
Bit 4 Bit 3  
Read: Bit 7  
Analog-to-Digital Results  
Register 4 (ADR4) Write:  
See page 64.  
Reset:  
Read:  
Indeterminate after reset  
Block Protect Register  
PTCON  
1
BPRT3  
1
BPRT2  
BPRT1  
BPRT0  
1
(BPROT) Write:  
See page 52.  
Reset:  
Read:  
0
0
0
1
1
EPROM Programming Control  
MBE  
ELAT  
EXCOL  
EXROW  
T1  
T0  
PGM  
$1036  
$1037  
Register (EPROG)(1) Write:  
See page 53.  
Reset:  
0
0
0
0
0
0
0
0
Reserved  
R
R
R
R
R
R
R
R
1. MC68HC711E20 only  
$1038  
Reserved  
R
R
R
R
R
R
R
R
Read:  
System Configuration Options  
ADPU  
CSEL  
IRQE(1)  
DLY(1)  
CME  
0
CR1(1)  
CR0(1)  
$1039  
$103A  
Register (OPTION) Write:  
See page 46.  
Reset:  
0
Bit 7  
0
0
Bit 6  
0
0
1
Bit 4  
0
0
Bit 2  
0
0
Bit 1  
0
0
Bit 0  
0
Read:  
Arm/Reset COP Timer Circuitry  
Bit 5  
Bit 3  
0
Register (COPRST) Write:  
See page 81.  
Reset:  
0
Read:  
EPROM and EEPROM Program-  
$103B ming Control Register (PPROG) Write:  
ODD  
0
EVEN  
0
ELAT(2)  
BYTE  
0
ROW  
0
ERASE  
0
EELAT  
0
EPGM  
0
See page 49.  
Reset:  
0
MDA  
0
Read:  
Highest Priority I Bit Interrupt and  
$103C Miscellaneous Register (HPRIO) Write:  
RBOOT  
0
SMOD  
0
IRV(NE)  
0
PSEL3  
0
PSEL2  
1
PSEL1  
1
PSEL0  
0
See page 41.  
Reset:  
Read:  
RAM and I/O Mapping Register  
RAM3  
RAM2  
RAM1  
RAM0  
REG3  
REG2  
REG1  
REG0  
1
$103D  
(INIT) Write:  
See page 45.  
Reset:  
0
0
0
0
0
0
0
= Unimplemented  
I = Indeterminate after reset  
R
= Reserved  
U = Unaffected  
Figure 2-7. Register and Control Bit Assignments (Sheet 5 of 6)  
M68HC11E Family Data Sheet, Rev. 5.1  
38  
Freescale Semiconductor  
Memory Map  
Addr.  
Register Name  
Reserved  
Bit 7  
6
5
4
3
2
1
Bit 0  
$103E  
R
R
R
R
R
R
R
R
Read:  
System Configuration Register  
NOSEC  
NOCOP ROMON  
EEON  
U
$103F  
$103F  
(CONFIG) Write:  
See page 43.  
Reset:  
0
EE3  
1
0
EE2  
1
0
EE1  
1
0
EE0  
1
U
NOSEC  
U
U
NOCOP  
U
1
Read:  
System Configuration Register  
EEON  
1
(CONFIG)(3) Write:  
See page 43.  
Reset:  
1
1. Can be written only once in first 64 cycles out of reset in normal modes or at any time during special modes.  
2. MC68HC711E9 only  
3. MC68HC811E2 only  
= Unimplemented  
R
= Reserved  
U = Unaffected  
I = Indeterminate after reset  
Figure 2-7. Register and Control Bit Assignments (Sheet 6 of 6)  
2.3.1 RAM and Input/Output Mapping  
Hardware priority is built into RAM and I/O mapping. Registers have priority over RAM and RAM has  
priority over ROM. When a lower priority resource is mapped at the same location as a higher priority  
resource, a read/write of a location results in a read/write of the higher priority resource only. For example,  
if both the register block and the RAM are mapped to the same location, only the register block will be  
accessed. If RAM and ROM are located at the same position, RAM has priority.  
The fully static RAM can be used to store instructions, variables, and temporary data. The direct  
addressing mode can access RAM locations using a 1-byte address operand, saving program memory  
space and execution time, depending on the application.  
RAM contents can be preserved during periods of processor inactivity by two methods, both of which  
reduce power consumption. They are:  
1. In the software-based stop mode, the clocks are stopped while VDD powers the MCU. Because  
power supply current is directly related to operating frequency in CMOS integrated circuits, only a  
very small amount of leakage exists when the clocks are stopped.  
2. In the second method, the MODB/VSTBY pin can supply RAM power from a battery backup or from  
a second power supply. Figure 2-8 shows a typical standby voltage circuit for a standard 5-volt  
device. Adjustments to the circuit must be made for devices that operate at lower voltages. Using  
the MODB/VSTBY pin may require external hardware, but can be justified when a significant amount  
of external circuitry is operating from VDD. If VSTBY is used to maintain RAM contents, reset must  
be held low whenever VDD is below normal operating level. Refer to Chapter 5 Resets and  
Interrupts.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
39  
Operating Modes and On-Chip Memory  
VDD  
MAX  
690  
VDD  
4.7 k  
TO MODB/VSTBY  
OF M68HC11  
VOUT  
VBATT  
4.8-V  
NiCd  
+
Figure 2-8. RAM Standby MODB/VSTBY Connections  
The bootloader program is contained in the internal bootstrap ROM. This ROM, which appears as internal  
memory space at locations $BF00–$BFFF, is enabled only if the MCU is reset in special bootstrap mode.  
In expanded modes, the ROM/EPROM/OTPROM (if present) is enabled out of reset and located at the  
top of the memory map if the ROMON bit in the CONFIG register is set. ROM or EPROM is enabled out  
of reset in single-chip and bootstrap modes, regardless of the state of ROMON.  
For devices with 512 bytes of EEPROM, the EEPROM is located at $B600–$B7FF and has the same read  
cycle time as the internal ROM. The 512 bytes of EEPROM cannot be remapped to other locations.  
For the MC68HC811E2, EEPROM is located at $F800–$FFFF and can be remapped to any 4-Kbyte  
boundary. EEPROM mapping control bits (EE[3:0] in CONFIG) determine the location of the 2048 bytes  
of EEPROM and are present only on the MC68HC811E2. Refer to 2.3.3.1 System Configuration Register  
for a description of the MC68HC811E2 CONFIG register.  
EEPROM can be programmed or erased by software and an on-chip charge pump, allowing EEPROM  
changes using the single VDD supply.  
2.3.2 Mode Selection  
The four mode variations are selected by the logic states of the MODA and MODB pins during reset. The  
MODA and MODB logic levels determine the logic state of SMOD and the MDA control bits in the highest  
priority I-bit interrupt and miscellaneous (HPRIO) register.  
After reset is released, the mode select pins no longer influence the MCU operating mode. In single-chip  
operating mode, the MODA pin is connected to a logic level 0. In expanded mode, MODA is normally  
connected to VDD through a pullup resistor of 4.7 k. The MODA pin also functions as the load instruction  
register LIR pin when the MCU is not in reset. The open-drain active low LIR output pin drives low during  
the first E cycle of each instruction. The MODB pin also functions as standby power input (VSTBY), which  
allows RAM contents to be maintained in absence of VDD  
.
Refer to Table 2-1, which is a summary of mode pin operation, the mode control bits, and the four  
operating modes.  
M68HC11E Family Data Sheet, Rev. 5.1  
40  
Freescale Semiconductor  
Memory Map  
Table 2-1. Hardware Mode Select Summary  
Input Levels  
at Reset  
Control Bits in HPRIO  
(Latched at Reset)  
Mode  
MODB  
MODA  
RBOOT  
SMOD  
MDA  
1
1
0
0
0
1
0
1
Single chip  
Expanded  
Bootstrap  
0
0
1
0
0
0
1
1
0
1
0
1
Special test  
A normal mode is selected when MODB is logic 1 during reset. One of three reset vectors is fetched from  
address $FFFA–$FFFF, and program execution begins from the address indicated by this vector. If  
MODB is logic 0 during reset, the special mode reset vector is fetched from addresses $BFFA–$BFFF,  
and software has access to special test features. Refer to Chapter 5 Resets and Interrupts.  
Address:  
Bit 7  
RBOOT(1) SMOD(1)  
$103C  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
MDA(1)  
IRV(NE)(1)  
PSEL3  
PSEL2  
PSEL1  
PSEL0  
Resets:  
Single chip:  
Expanded:  
Bootstrap:  
Test:  
0
0
1
0
0
0
1
1
0
1
0
1
0
0
0
1
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1. The reset values depend on the mode selected at the RESET pin rising edge.  
Figure 2-9. Highest Priority I-Bit Interrupt and Miscellaneous  
Register (HPRIO)  
RBOOT — Read Bootstrap ROM Bit  
Valid only when SMOD is set (bootstrap or special test mode); can be written only in special modes  
0 = Bootloader ROM disabled and not in map  
1 = Bootloader ROM enabled and in map at $BE00–$BFFF  
SMOD and MDA — Special Mode Select and Mode Select A Bits  
The initial value of SMOD is the inverse of the logic level present on the MODB pin at the rising edge  
of reset. The initial value of MDA equals the logic level present on the MODA pin at the rising edge of  
reset. These two bits can be read at any time. They can be written anytime in special modes. MDA can  
be written only once in normal modes. SMOD cannot be set once it has been cleared.  
Input  
Latched at Reset  
Mode  
MODB  
MODA  
SMOD  
MDA  
1
1
0
1
Single chip  
Expanded  
0
0
0
1
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
41  
Operating Modes and On-Chip Memory  
0
0
0
1
Bootstrap  
1
1
0
1
Special test  
IRV(NE) — Internal Read Visibility (Not E) Bit  
IRVNE can be written once in any mode. In expanded modes, IRVNE determines whether IRV is on  
or off. In special test mode, IRVNE is reset to 1. In all other modes, IRVNE is reset to 0. For the  
MC68HC811E2, this bit is IRV and only controls the internal read visibility function.  
0 = No internal read visibility on external bus  
1 = Data from internal reads is driven out the external data bus.  
In single-chip modes this bit determines whether the E clock drives out from the chip. For the  
MC68HC811E2, this bit has no meaning or effect in single-chip and bootstrap modes.  
0 = E is driven out from the chip.  
1 = E pin is driven low. Refer to the following table.  
IRVNE Out  
of Reset  
E Clock Out  
of Reset  
IRV Out  
of Reset  
IRVNE  
Affects Only  
IRVNE Can  
Be Written  
Mode  
Single chip  
Expanded  
Bootstrap  
0
0
0
1
On  
On  
On  
On  
Off  
Off  
Off  
On  
E
Once  
Once  
Once  
Once  
IRV  
E
Special test  
IRV  
PSEL[3:0] — Priority Select Bits  
Refer to Chapter 5 Resets and Interrupts.  
2.3.3 System Initialization  
Registers and bits that control initialization and the basic operation of the MCU are protected against  
writes except under special circumstances. Table 2-2 lists registers that can be written only once after  
reset or that must be written within the first 64 cycles after reset.  
Table 2-2. Write Access Limited Registers  
Operating Register  
Must be Written  
in First 64 Cycles  
Write  
Anytime  
Register Name  
Mode  
Address  
SMOD = 0  
$x024 Timer interrupt mask 2 (TMSK2)  
$x035 Block protect register (BPROT)  
$x039 System configuration options (OPTION)  
Bits [1:0], once only  
Clear bits, once only  
Bits [5:4], bits [2:0], once only Bits [7:6], bit 3  
Bits [7:2]  
Set bits only  
Highest priority I-bit interrupt  
$x03C  
See HPRIO description  
See HPRIO description  
and miscellaneous (HPRIO)  
$x03D RAM and I/O map register (INIT)  
$x024 Timer interrupt mask 2 (TMSK2)  
$x035 Block protect register (BPROT)  
$x039 System configuration options (OPTION)  
Yes, once only  
All, set or clear  
All, set or clear  
All, set or clear  
SMOD = 1  
Highest priority I-bit interrupt and  
$x03C  
See HPRIO description  
See HPRIO description  
All, set or clear  
miscellaneous (HPRIO)  
$x03D RAM and I/O map register (INIT)  
M68HC11E Family Data Sheet, Rev. 5.1  
42  
Freescale Semiconductor  
Memory Map  
2.3.3.1 System Configuration Register  
The system configuration register (CONFIG) consists of an EEPROM byte and static latches that control  
the startup configuration of the MCU. The contents of the EEPROM byte are transferred into static  
working latches during reset sequences. The operation of the MCU is controlled directly by these latches  
and not by CONFIG itself. In normal modes, changes to CONFIG do not affect operation of the MCU until  
after the next reset sequence. When programming, the CONFIG register itself is accessed. When the  
CONFIG register is read, the static latches are accessed. See 2.5.1 EEPROM and CONFIG  
Programming and Erasure for information on modifying CONFIG.  
To take full advantage of the MCU’s functionality, customers can program the CONFIG register in  
bootstrap mode. This can be accomplished by setting the mode pins to logic 0 and downloading a small  
program to internal RAM. For more information, Freescale application note AN1060 entitled M68HC11  
Bootstrap Mode has been included at the back of this document. The downloadable talker will consist of:  
Bulk erase  
Byte programming  
Communication server  
All of this functionality is provided by PCbug11 which can be found on the Freescale Web site at  
http://www.freescale.com. For more information on using PCbug11 to program an E-series device,  
Freescale engineering bulletin EB296 entitled Programming MC68HC711E9 Devices with PCbug11 and  
the M68HC11EVBU has been included at the back of this document.  
NOTE  
The CONFIG register on the 68HC11 is an EEPROM cell and must be  
programmed accordingly.  
Operation of the CONFIG register in the MC68HC811E2 differs from other devices in the M68HC11 E  
series. See Figure 2-10 and Figure 2-11.  
Address: $103F  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
NOSEC  
NOCOP  
ROMON  
EEON  
Resets:  
Single chip:  
Bootstrap:  
Expanded:  
Test:  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U
U
1
U
1
U
U
U
U
U
U
U
U(L)  
U
1
U(L)  
= Unimplemented  
U indicates a previously programmed bit. U(L) indicates that the bit resets to the logic level held in the latch prior to reset,  
but the function of COP is controlled by the DISR bit in TEST1 register.  
Figure 2-10. System Configuration Register (CONFIG)  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
43  
Operating Modes and On-Chip Memory  
Address:  
$103F  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
EE3  
EE2  
EE1  
EE0  
NOSEC  
NOCOP  
EEON  
Resets:  
Single chip:  
Bootstrap:  
Expanded:  
Test:  
1
1
1
1
1
1
1
1
U
U
1
U
1
1
1
1
1
1
U(L)  
U
U
U
U
U
U
U
U
U
U
0
1
U(L)  
= Unimplemented  
U indicates a previously programmed bit. U(L) indicates that the bit resets to the logic level held in the latch prior to reset,  
but the function of COP is controlled by the DISR bit in TEST1 register.  
Figure 2-11. MC68HC811E2 System Configuration Register (CONFIG)  
EE[3:0] — EEPROM Mapping Bits  
EE[3:0] apply only to MC68HC811E2 and allow the 2048 bytes of EEPROM to be remapped to any  
4-Kbyte boundary. See Table 2-3.  
Table 2-3. EEPROM Mapping  
EE[3:0]  
0 0 0 0  
0 0 0 1  
0 0 1 0  
0 0 1 1  
0 1 0 0  
0 1 0 1  
0 1 1 0  
0 1 1 1  
1 0 0 0  
1 0 0 1  
1 0 1 0  
1 0 1 1  
1 1 0 0  
1 1 0 1  
1 1 1 0  
1 1 1 1  
EEPROM Location  
$0800–$0FFF  
$1800–$1FFF  
$2800–$2FFF  
$3800–$3FFF  
$4800–$4FFF  
$5800–$5FFF  
$6800–$6FFF  
$7800–$7FFF  
$8800–$8FFF  
$9800–$9FFF  
$A800–$AFFF  
$B800–$BFFF  
$C800–$CFFF  
$D800–$DFFF  
$E800–$EFFF  
$F800–$FFFF  
M68HC11E Family Data Sheet, Rev. 5.1  
44  
Freescale Semiconductor  
Memory Map  
NOSEC — Security Disable Bit  
NOSEC is invalid unless the security mask option is specified before the MCU is manufactured. If the  
security mask option is omitted NOSEC always reads 1. The enhanced security feature is available in  
the MC68S711E9 MCU. The enhancement to the standard security feature protects the EPROM as  
well as RAM and EEPROM.  
0 = Security enabled  
1 = Security disabled  
NOCOP — COP System Disable Bit  
Refer to Chapter 5 Resets and Interrupts.  
1 = COP disabled  
0 = COP enabled  
ROMON — ROM/EPROM/OTPROM Enable Bit  
When this bit is 0, the ROM or EPROM is disabled and that memory space becomes externally  
addressed. In single-chip mode, ROMON is forced to 1 to enable ROM/EPROM regardless of the state  
of the ROMON bit.  
0 = ROM disabled from the memory map  
1 = ROM present in the memory map  
EEON — EEPROM Enable Bit  
When this bit is 0, the EEPROM is disabled and that memory space becomes externally addressed.  
0 = EEPROM removed from the memory map  
1 = EEPROM present in the memory map  
2.3.3.2 RAM and I/O Mapping Register  
The internal registers used to control the operation of the MCU can be relocated on 4-Kbyte boundaries  
within the memory space with the use of the RAM and I/O mapping register (INIT). This 8-bit  
special-purpose register can change the default locations of the RAM and control registers within the  
MCU memory map. It can be written only once within the first 64 E-clock cycles after a reset in normal  
modes, and then it becomes a read-only register.  
Address: $103D  
Bit 7  
RAM3  
0
6
RAM2  
0
5
RAM1  
0
4
RAM0  
0
3
REG3  
0
2
REG2  
0
1
REG1  
0
Bit 0  
REG0  
1
Read:  
Write:  
Reset:  
Figure 2-12. RAM and I/O Mapping Register (INIT)  
RAM[3:0] — RAM Map Position Bits  
These four bits, which specify the upper hexadecimal digit of the RAM address, control position of RAM  
in the memory map. RAM can be positioned at the beginning of any 4-Kbyte page in the memory map.  
It is initialized to address $0000 out of reset. Refer to Table 2-4.  
REG[3:0] — 64-Byte Register Block Position  
These four bits specify the upper hexadecimal digit of the address for the 64-byte block of internal  
registers. The register block, positioned at the beginning of any 4-Kbyte page in the memory map, is  
initialized to address $1000 out of reset. Refer to Table 2-5.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
45  
Operating Modes and On-Chip Memory  
Table 2-4. RAM Mapping  
Table 2-5. Register Mapping  
RAM[3:0]  
0000  
0001  
0010  
0011  
0100  
0101  
0110  
0111  
1000  
1001  
1010  
1011  
1100  
1101  
1110  
1111  
Address  
REG[3:0]  
0000  
0001  
0010  
0011  
0100  
0101  
0110  
0111  
1000  
1001  
1010  
1011  
1100  
1101  
1110  
1111  
Address  
$0000–$0xFF  
$1000–$1xFF  
$2000–$2xFF  
$3000–$3xFF  
$4000–$4xFF  
$5000–$5xFF  
$6000–$6xFF  
$7000–$7xFF  
$8000–$8xFF  
$9000–$9xFF  
$A000–$AxFF  
$B000–$BxFF  
$C000–$CxFF  
$D000–$DxFF  
$E000–$ExFF  
$F000–$FxFF  
$0000–$003F  
$1000–$103F  
$2000–$203F  
$3000–$303F  
$4000–$403F  
$5000–$503F  
$6000–$603F  
$7000–$703F  
$8000–$803F  
$9000–$903F  
$A000–$A03F  
$B000–$B03F  
$C000–$C03F  
$D000–$D03F  
$E000–$E03F  
$F000–$F03F  
2.3.3.3 System Configuration Options Register  
The 8-bit, special-purpose system configuration options register (OPTION) sets internal system  
configuration options during initialization. The time protected control bits, IRQE, DLY, and CR[1:0], can  
be written only once after a reset and then they become read-only. This minimizes the possibility of any  
accidental changes to the system configuration.  
Address: $1039  
Bit 7  
ADPU  
0
6
CSEL  
0
5
IRQE(1)  
0
4
DLY(1)  
1
3
CME  
0
2
1
CR1(1)  
0
Bit 0  
CR0(1)  
0
Read:  
Write:  
Reset:  
0
1. Can be written only once in first 64 cycles out of reset in normal modes or at any time during  
special modes.  
= Unimplemented  
Figure 2-13. System Configuration Options Register (OPTION)  
ADPU — Analog-to-Digital Converter Power-Up Bit  
Refer to Chapter 3 Analog-to-Digital (A/D) Converter.  
CSEL — Clock Select Bit  
Selects alternate clock source for on-chip EEPROM charge pump. Refer to 2.5.1 EEPROM and  
CONFIG Programming and Erasure for more information on EEPROM use.  
CSEL also selects the clock source for the A/D converter, a function discussed in Chapter 3  
Analog-to-Digital (A/D) Converter.  
M68HC11E Family Data Sheet, Rev. 5.1  
46  
Freescale Semiconductor  
EPROM/OTPROM  
IRQE — Configure IRQ for Edge-Sensitive Only Operation Bit  
Refer to Chapter 5 Resets and Interrupts.  
DLY — Enable Oscillator Startup Delay Bit  
0 = The oscillator startup delay coming out of stop mode is bypassed and the MCU resumes  
processing within about four bus cycles.  
1 = A delay of approximately 4000 E-clock cycles is imposed as the MCU is started up from the stop  
power-saving mode. This delay allows the crystal oscillator to stabilize.  
CME — Clock Monitor Enable Bit  
Refer to Chapter 5 Resets and Interrupts.  
Bit 2 — Not implemented  
Always reads 0  
CR[1:0] — COP Timer Rate Select Bits  
The internal E clock is divided by 215 before it enters the COP watchdog system. These control bits  
determine a scaling factor for the watchdog timer. Refer to Chapter 5 Resets and Interrupts.  
2.4 EPROM/OTPROM  
Certain devices in the M68HC11 E series include on-chip EPROM/OTPROM. For instance:  
The MC68HC711E9 devices contain 12 Kbytes of on-chip EPROM (OTPROM in non-windowed  
package).  
The MC68HC711E20 has 20 Kbytes of EPROM (OTPROM in non-windowed package).  
The MC68HC711E32 has 32 Kbytes of EPROM (OTPROM in non-windowed package).  
Standard MC68HC71E9 and MC68HC711E20 devices are shipped with the EPROM/OTPROM contents  
erased (all 1s). The programming operation programs zeros. Windowed devices must be erased using a  
suitable ultraviolet light source before reprogramming. Depending on the light source, erasing can take  
from 15 to 45 minutes.  
Using the on-chip EPROM/OTPROM programming feature requires an external 12-volt nominal power  
supply (VPPE). Normal programming is accomplished using the EPROM/OTPROM programming register  
(PPROG).  
PPROG is the combined EPROM/OTPROM and EEPROM programming register on all devices with  
EPROM/OTPROM except the MC68HC711E20. For the MC68HC711E20, there is a separate register for  
EPROM/OTPROM programming called the EPROG register.  
As described in the following subsections, these two methods of programming and verifying EPROM are  
possible:  
1. Programming an individual EPROM address  
2. Programming the EPROM with downloaded data  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
47  
Operating Modes and On-Chip Memory  
2.4.1 Programming an Individual EPROM Address  
In this method, the MCU programs its own EPROM by controlling the PPROG register (EPROG in  
MC68HC711E20). Use these procedures to program the EPROM through the MCU with:  
The ROMON bit set in the CONFIG register  
The 12-volt nominal programming voltage present on the XIRQ/VPPE pin  
The IRQ pin must be pulled high.  
NOTE  
Any operating mode can be used.  
This example applies to all devices with EPROM/OTPROM except for the MC68HC711E20.  
EPROG  
LDAB  
STAB  
#$20  
$103B Set ELAT bit in (EPGM = 0) to enable  
EPROM latches.  
STAA  
LDAB  
STAB  
$0,X  
#$21  
Store data to EPROM address  
$103B Set EPGM bit with ELAT = 1 to enable  
EPROM programming voltage  
JSR  
CLR  
DLYEP Delay 2–4 ms  
$103B Turn off programming voltage and set  
to READ mode  
This example applies only to MC68HC711E20.  
EPROG  
LDAB  
STAB  
#$20  
$1036 Set ELAT bit (EPGM = 0) to enable  
EPROM latches.  
STAA  
LDAB  
STAB  
$0,X  
#$21  
Store data to EPROM address  
$1036 Set EPGM bit with ELAT = 1 to enable  
EPROM programming voltage  
JSR  
CLR  
DLYEP Delay 2–4 ms  
$1036 Turn off programming voltage and set  
to READ mode  
2.4.2 Programming the EPROM with Downloaded Data  
When using this method, the EPROM is programmed by software while in the special test or bootstrap  
modes. User-developed software can be uploaded through the SCI or a ROM-resident EPROM  
programming utility can be used. The 12-volt nominal programming voltage must be present on the  
XIRQ/VPPE pin. To use the resident utility, bootload a 3-byte program consisting of a single jump  
instruction to $BF00. $BF00 is the starting address of a resident EPROM programming utility. The utility  
program sets the X and Y index registers to default values, then receives programming data from an  
external host, and puts it in EPROM. The value in IX determines programming delay time. The value in  
IY is a pointer to the first address in EPROM to be programmed (default = $D000).  
When the utility program is ready to receive programming data, it sends the host the $FF character. Then  
it waits. When the host sees the $FF character, the EPROM programming data is sent, starting with the  
first location in the EPROM array. After the last byte to be programmed is sent and the corresponding  
verification data is returned, the programming operation is terminated by resetting the MCU.  
For more information, Freescale application note AN1060 entitled M68HC11 Bootstrap Mode has been  
included at the back of this document.  
M68HC11E Family Data Sheet, Rev. 5.1  
48  
Freescale Semiconductor  
EPROM/OTPROM  
2.4.3 EPROM and EEPROM Programming Control Register  
The EPROM and EEPROM programming control register (PPROG) enables the EPROM programming  
voltage and controls the latching of data to be programmed.  
For MC68HC711E9, PPROG is also the EEPROM programming control register.  
For the MC68HC711E20, EPROM programming is controlled by the EPROG register and  
EEPROM programming is controlled by the PPROG register.  
Address: $103B  
Bit 7  
ODD  
0
6
EVEN  
0
5
ELAT(1)  
0
4
BYTE  
0
3
ROW  
0
2
ERASE  
0
1
EELAT  
0
Bit 0  
EPGM  
0
Read:  
Write:  
Reset:  
1. MC68HC711E9 only  
Figure 2-14. EPROM and EEPROM Programming  
Control Register (PPROG)  
ODD — Program Odd Rows in Half of EEPROM (Test) Bit  
Refer to 2.5 EEPROM.  
EVEN — Program Even Rows in Half of EEPROM (Test) Bit  
Refer to 2.5 EEPROM.  
ELAT — EPROM/OTPROM Latch Control Bit  
When ELAT = 1, writes to EPROM cause address and data to be latched and the EPROM/OTPROM  
cannot be read. ELAT can be read any time. ELAT can be written any time except when EPGM = 1;  
then the write to ELAT is disabled.  
0 = EPROM address and data bus configured for normal reads  
1 = EPROM address and data bus configured for programming  
For the MC68HC711E9:  
a. EPGM enables the high voltage necessary for both EEPROM and EPROM/OTPROM  
programming.  
b. ELAT and EELAT are mutually exclusive and cannot both equal 1.  
BYTE — Byte/Other EEPROM Erase Mode Bit  
Refer to 2.5 EEPROM.  
ROW — Row/All EEPROM Erase Mode Bit  
Refer to 2.5 EEPROM.  
ERASE — Erase Mode Select Bit  
Refer to 2.5 EEPROM.  
EELAT — EEPROM Latch Control Bit  
Refer to 2.5 EEPROM.  
EPGM —EPROM/OTPROM/EEPROM Programming Voltage Enable Bit  
EPGM can be read any time and can be written only when ELAT = 1 (for EPROM/OTPROM  
programming) or when EELAT = 1 (for EEPROM programming).  
0 = Programming voltage to EPROM/OTPROM/EEPROM array disconnected  
1 = Programming voltage to EPROM/OTPROM/EEPROM array connected  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
49  
Operating Modes and On-Chip Memory  
Address: $1036  
Bit 7  
MBE  
0
6
5
ELAT  
0
4
EXCOL  
0
3
EXROW  
0
2
T1  
0
1
T0  
0
Bit 0  
PGM  
0
Read:  
Write:  
Reset:  
0
= Unimplemented  
Figure 2-15. MC68HC711E20 EPROM Programming  
Control Register (EPROG)  
MBE — Multiple-Byte Programming Enable Bit  
When multiple-byte programming is enabled, address bit 5 is considered a don’t care so that bytes with  
address bit 5 = 0 and address bit 5 = 1 both get programmed. MBE can be read in any mode and  
always reads 0 in normal modes. MBE can be written only in special modes.  
0 = EPROM array configured for normal programming  
1 = Program two bytes with the same data  
Bit 6 — Unimplemented  
Always reads 0  
ELAT — EPROM/OTPROM Latch Control Bit  
When ELAT = 1, writes to EPROM cause address and data to be latched and the EPROM/OTPROM  
cannot be read. ELAT can be read any time. ELAT can be written any time except when PGM = 1; then  
the write to ELAT is disabled.  
0 = EPROM/OTPROM address and data bus configured for normal reads  
1 = EPROM/OTPROM address and data bus configured for programming  
EXCOL — Select Extra Columns Bit  
0 = User array selected  
1 = User array is disabled and extra columns are accessed at bits [7:0]. Addresses use bits [13:5]  
and bits [4:0] are don’t care. EXCOL can be read and written only in special modes and always  
returns 0 in normal modes.  
EXROW — Select Extra Rows Bit  
0 = User array selected  
1 = User array is disabled and two extra rows are available. Addresses use bits [7:0] and bits [13:8]  
are don’t care. EXROW can be read and written only in special modes and always returns 0 in  
normal modes.  
T[1:0] — EPROM Test Mode Select Bits  
These bits allow selection of either gate stress or drain stress test modes. They can be read and written  
only in special modes and always read 0 in normal modes.  
T1  
0
T0  
0
Function Selected  
Normal mode  
Reserved  
0
1
1
0
Gate stress  
1
1
Drain stress  
M68HC11E Family Data Sheet, Rev. 5.1  
50  
Freescale Semiconductor  
EEPROM  
PGM — EPROM Programming Voltage Enable Bit  
PGM can be read any time and can be written only when ELAT = 1.  
0 = Programming voltage to EPROM array disconnected  
1 = Programming voltage to EPROM array connected  
2.5 EEPROM  
Some E-series devices contain 512 bytes of on-chip EEPROM. The MC68HC811E2 contains 2048 bytes  
of EEPROM with selectable base address. All E-series devices contain the EEPROM-based CONFIG  
register.  
2.5.1 EEPROM and CONFIG Programming and Erasure  
The erased state of an EEPROM bit is 1. During a read operation, bit lines are precharged to 1. The  
floating gate devices of programmed bits conduct and pull the bit lines to 0. Unprogrammed bits remain  
at the precharged level and are read as ones. Programming a bit to 1 causes no change. Programming  
a bit to 0 changes the bit so that subsequent reads return 0.  
When appropriate bits in the BPROT register are cleared, the PPROG register controls programming and  
erasing the EEPROM. The PPROG register can be read or written at any time, but logic enforces defined  
programming and erasing sequences to prevent unintentional changes to EEPROM data. When the  
EELAT bit in the PPROG register is cleared, the EEPROM can be read as if it were a ROM.  
The on-chip charge pump that generates the EEPROM programming voltage from VDD uses MOS  
capacitors, which are relatively small in value. The efficiency of this charge pump and its drive capability  
are affected by the level of VDD and the frequency of the driving clock. The load depends on the number  
of bits being programmed or erased and capacitances in the EEPROM array.  
The clock source driving the charge pump is software selectable. When the clock select (CSEL) bit in the  
OPTION register is 0, the E clock is used; when CSEL is 1, an on-chip resistor-capacitor (RC) oscillator  
is used.  
The EEPROM programming voltage power supply voltage to the EEPROM array is not enabled until there  
has been a write to PPROG with EELAT set and PGM cleared. This must be followed by a write to a valid  
EEPROM location or to the CONFIG address, and then a write to PPROG with both the EELAT and  
EPGM bits set. Any attempt to set both EELAT and EPGM during the same write operation results in  
neither bit being set.  
2.5.1.1 Block Protect Register  
This register prevents inadvertent writes to both the CONFIG register and EEPROM. The active bits in  
this register are initialized to 1 out of reset and can be cleared only during the first 64 E-clock cycles after  
reset in the normal modes. When these bits are cleared, the associated EEPROM section and the  
CONFIG register can be programmed or erased. EEPROM is only visible if the EEON bit in the CONFIG  
register is set. The bits in the BPROT register can be written to 1 at any time to protect EEPROM and the  
CONFIG register. In test or bootstrap modes, write protection is inhibited and BPROT can be written  
repeatedly. Address ranges for protected areas of EEPROM differ significantly for the MC68HC811E2.  
Refer to Figure 2-16.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
51  
Operating Modes and On-Chip Memory  
Address: $1035  
Bit 7  
6
5
0
4
PTCON  
1
3
BPRT3  
1
2
BPRT2  
1
1
BPRT1  
1
Bit 0  
BPRT0  
1
Read:  
Write:  
Reset:  
0
0
= Unimplemented  
Figure 2-16. Block Protect Register (BPROT)  
Bits [7:5] — Unimplemented  
Always read 0  
PTCON — Protect CONFIG Register Bit  
0 = CONFIG register can be programmed or erased normally.  
1 = CONFIG register cannot be programmed or erased.  
BPRT[3:0] — Block Protect Bits for EEPROM  
When set, these bits protect a block of EEPROM from being programmed or electronically erased.  
Ultraviolet light, however, can erase the entire EEPROM contents regardless of BPRT[3:0] (windowed  
packages only). Refer to Table 2-6 and Table 2-7.  
When cleared, BPRT[3:0] allow programming and erasure of the associated block.  
Table 2-6. EEPROM Block Protect  
Bit Name  
BPRT0  
BPRT1  
BPRT2  
BPRT3  
Block Protected  
$B600–$B61F  
$B620–$B65F  
$B660–$B6DF  
$B6E0–$B7FF  
Block Size  
32 bytes  
64 bytes  
128 bytes  
288 bytes  
Table 2-7. EEPROM Block Protect in MC68HC811E2 MCUs  
Bit Name  
BPRT0  
BPRT1  
BPRT2  
BPRT3  
Block Protected  
$x800–$x9FF(1)  
$xA00–$xBFF(1)  
$xC00–$xDFF(1)  
$xE00–$xFFF(1)  
Block Size  
512 bytes  
512 bytes  
512 bytes  
512 bytes  
1. x is determined by the value of EE[3:0] in CONFIG register. Refer to Figure  
2-13.  
M68HC11E Family Data Sheet, Rev. 5.1  
52  
Freescale Semiconductor  
EEPROM  
2.5.1.2 EPROM and EEPROM Programming Control Register  
The EPROM and EEPROM programming control register (PPROG) selects and controls the EEPROM  
programming function. Bits in PPROG enable the programming voltage, control the latching of data to be  
programmed, and select the method of erasure (for example, byte, row, etc.).  
Address: $103B  
Bit 7  
ODD  
0
6
EVEN  
0
5
ELAT(1)  
0
4
BYTE  
0
3
ROW  
0
2
ERASE  
0
1
EELAT  
0
Bit 0  
EPGM  
0
Read:  
Write:  
Reset:  
1. MC68HC711E9 only  
Figure 2-17. EPROM and EEPROM Programming  
Control Register (PPROG)  
ODD — Program Odd Rows in Half of EEPROM (Test) Bit  
EVEN — Program Even Rows in Half of EEPROM (Test) Bit  
ELAT — EPROM/OTPROM Latch Control Bit  
For the MC68HC711E9, EPGM enables the high voltage necessary for both EPROM/OTPROM and  
EEPROM programming.  
For MC68HC711E9, ELAT and EELAT are mutually exclusive and cannot both equal 1.  
0 = EPROM address and data bus configured for normal reads  
1 = EPROM address and data bus configured for programming  
BYTE — Byte/Other EEPROM Erase Mode Bit  
This bit overrides the ROW bit.  
0 = Row or bulk erase  
1 = Erase only one byte  
ROW — Row/All EEPROM Erase Mode Bit  
If BYTE is 1, ROW has no meaning.  
0 = Bulk erase  
1 = Row erase  
Table 2-8. EEPROM Erase  
BYTE  
ROW  
Action  
Bulk erase (entire array)  
Row erase (16 bytes)  
Byte erase  
0
0
1
1
0
1
0
1
Byte erase  
ERASE — Erase Mode Select Bit  
0 = Normal read or program mode  
1 = Erase mode  
EELAT — EEPROM Latch Control Bit  
0 = EEPROM address and data bus configured for normal reads and cannot be programmed  
1 = EEPROM address and data bus configured for programming or erasing and cannot be read  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
53  
Operating Modes and On-Chip Memory  
EPGM — EPROM/OTPROM/EEPROM Programming Voltage Enable Bit  
0 = Programming voltage to EEPROM array switched off  
1 = Programming voltage to EEPROM array switched on  
During EEPROM programming, the ROW and BYTE bits of PPROG are not used. If the frequency of the  
E clock is 1 MHz or less, set the CSEL bit in the OPTION register. Recall that 0s must be erased by a  
separate erase operation before programming. The following examples of how to program an EEPROM  
byte assume that the appropriate bits in BPROT are cleared.  
PROG  
LDAB  
STAB  
STAA  
#$02  
EELAT = 1  
$103B Set EELAT bit  
$XXXX Store data to EEPROM address  
(for valid EEPROM address see memory  
map for each device)  
LDAB  
STAB  
JSR  
#$03  
EELAT = 1, EPGM = 1  
$103B Turn on programming voltage  
DLY10 Delay 10 ms  
$103B Turn off high voltage and set  
to READ mode  
CLR  
2.5.1.3 EEPROM Bulk Erase  
This is an example of how to bulk erase the entire EEPROM. The CONFIG register is not affected in this  
example.  
BULKE  
LDAB  
STAB  
STAA  
#$06  
EELAT = 1, ERASE = 1  
$103B Set to BULK erase mode  
$XXXX Store data to any EEPROM address (for  
valid EEPROM address see memory map  
for each device)  
LDAB  
STAB  
JSR  
#$07  
EELAT = 1, EPGM = 1, ERASE = 1  
$103B Turn on high voltage  
DLY10 Delay 10 ms  
$103B Turn off high voltage and set  
to READ mode  
CLR  
2.5.1.4 EEPROM Row Erase  
This example shows how to perform a fast erase of large sections of EEPROM.  
ROWE  
LDAB  
STAB  
STAB  
LDAB  
STAB  
JSR  
#$0E  
ROW = 1, ERASE = 1, EELAT = 1  
Write any data to any address in ROW  
$103B Set to ROW erase mode  
0,X  
#$0F  
$103B Turn on high voltage  
DLY10 Delay 10 ms  
ROW = 1, ERASE = 1, EELAT = 1, EPGM = 1  
CLR  
$103B Turn off high voltage and set  
to READ mode  
M68HC11E Family Data Sheet, Rev. 5.1  
54  
Freescale Semiconductor  
EEPROM  
2.5.1.5 EEPROM Byte Erase  
This is an example of how to erase a single byte of EEPROM.  
BYTEE  
LDAB  
STAB  
STAB  
LDAB  
#$16  
BYTE = 1, ERASE = 1, EELAT = 1  
$103B Set to BYTE erase mode  
0,X  
#$17  
Write any data to address to be erased  
BYTE = 1, ERASE = 1, EELAT = 1,  
EPGM = 1  
STAB  
JSR  
CLR  
$103B Turn on high voltage  
DLY10 Delay 10 ms  
$103B Turn off high voltage and set  
to READ mode  
2.5.1.6 CONFIG Register Programming  
Because the CONFIG register is implemented with EEPROM cells, use EEPROM procedures to erase  
and program this register. The procedure for programming is the same as for programming a byte in the  
EEPROM array, except that the CONFIG register address is used. CONFIG can be programmed or  
erased (including byte erase) while the MCU is operating in any mode, provided that PTCON in BPROT  
is clear.  
To change the value in the CONFIG register, complete this procedure.  
1. Erase the CONFIG register.  
2. Program the new value to the CONFIG address.  
3. Initiate reset.  
NOTE  
Do not initiate a reset until the procedure is complete.  
2.5.2 EEPROM Security  
The optional security feature, available only on ROM-based MCUs, protects the EEPROM and RAM  
contents from unauthorized access. A program, or a key portion of a program, can be protected against  
unauthorized duplication. To accomplish this, the protection mechanism restricts operation of protected  
devices to the single-chip modes. This prevents the memory locations from being monitored externally  
because single-chip modes do not allow visibility of the internal address and data buses. Resident  
programs, however, have unlimited access to the internal EEPROM and RAM and can read, write, or  
transfer the contents of these memories.  
An enhanced security feature which protects EPROM contents, RAM, and EEPROM from unauthorized  
accesses is available in MC68S711E9. Refer to Chapter 11 Ordering Information and Mechanical  
Specifications for the exact part number.  
For further information, these engineering bulletins have been included at the back of this data book:  
EB183 — Enabling the Security Feature on the MC68HC711E9 Devices with PCbug11 on the  
M68HC711E9PGMR  
EB188 — Enabling the Security Feature on M68HC811E2 Devices with PCbug11 on the  
M68HC711E9PGMR  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
55  
Operating Modes and On-Chip Memory  
M68HC11E Family Data Sheet, Rev. 5.1  
56  
Freescale Semiconductor  
Chapter 3  
Analog-to-Digital (A/D) Converter  
3.1 Introduction  
The analog-to-digital (A/D) system, a successive approximation converter, uses an all-capacitive charge  
redistribution technique to convert analog signals to digital values.  
3.2 Overview  
The A/D system is an 8-channel, 8-bit, multiplexed-input converter. The converter does not require  
external sample and hold circuits because of the type of charge redistribution technique used. A/D  
converter timing can be synchronized to the system E clock or to an internal resistor capacitor (RC)  
oscillator.  
The A/D converter system consists of four functional blocks: multiplexer, analog converter, digital control,  
and result storage. Refer to Figure 3-1.  
3.2.1 Multiplexer  
The multiplexer selects one of 16 inputs for conversion. Input selection is controlled by the value of bits  
CD:CA in the ADCTL register. The eight port E pins are fixed-direction analog inputs to the multiplexer,  
and additional internal analog signal lines are routed to it.  
Port E pins also can be used as digital inputs. Digital reads of port E pins are not recommended during  
the sample portion of an A/D conversion cycle, when the gate signal to the N-channel input gate is on.  
Because no P-channel devices are directly connected to either input pins or reference voltage pins,  
voltages above VDD do not cause a latchup problem, although current should be limited according to  
maximum ratings. Refer to Figure 3-2, which is a functional diagram of an input pin.  
3.2.2 Analog Converter  
Conversion of an analog input selected by the multiplexer occurs in this block. It contains a  
digital-to-analog capacitor (DAC) array, a comparator, and a successive approximation register (SAR).  
Each conversion is a sequence of eight comparison operations, beginning with the most significant bit  
(MSB). Each comparison determines the value of a bit in the successive approximation register.  
The DAC array performs two functions. It acts as a sample and hold circuit during the entire conversion  
sequence and provides comparison voltage to the comparator during each successive comparison.  
The result of each successive comparison is stored in the SAR. When a conversion sequence is  
complete, the contents of the SAR are transferred to the appropriate result register.  
A charge pump provides switching voltage to the gates of analog switches in the multiplexer. Charge  
pump output must stabilize between 7 and 8 volts within up to 100 µs before the converter can be used.  
The charge pump is enabled by the ADPU bit in the OPTION register.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
57  
Analog-to-Digital (A/D) Converter  
PE0  
AN0  
VRH  
8-BIT CAPACITIVE DAC  
WITH SAMPLE AND HOLD  
VRl  
PE1  
AN1  
PE2  
AN2  
SUCCESSIVE APPROXIMATION  
REGISTER AND CONTROL  
PE3  
AN3  
RESULT  
ANALOG  
MUX  
PE4  
AN4  
PE5  
AN5  
INTERNAL  
DATA BUS  
PE6  
AN6  
PE7  
AN7  
ADCTL A/D CONTROL  
RESULT REGISTER INTERFACE  
ADR1 A/D RESULT 1  
ADR2 A/D RESULT 2  
ADR3 A/D RESULT 3  
ADR4 A/D RESULT 4  
Figure 3-1. A/D Converter Block Diagram  
DIFFUSION/POLY  
COUPLER  
ANALOG  
INPUT  
PIN  
*
~ 20 pF  
+ ~20 V  
– ~0.7 V  
+ ~12V  
– ~0.7V  
ð 4 kΩ  
< 2 pF  
400 nA  
JUNCTION  
LEAKAGE  
DAC  
CAPACITANCE  
DUMMY N-CHANNEL  
OUTPUT DEVICE  
INPUT  
PROTECTION  
DEVICE  
VRL  
* THIS ANALOG SWITCH IS CLOSED ONLY DURING THE 12-CYCLE SAMPLE TIME.  
Figure 3-2. Electrical Model of an A/D Input Pin (Sample Mode)  
M68HC11E Family Data Sheet, Rev. 5.1  
58  
Freescale Semiconductor  
Overview  
3.2.3 Digital Control  
All A/D converter operations are controlled by bits in register ADCTL. In addition to selecting the analog  
input to be converted, ADCTL bits indicate conversion status and control whether single or continuous  
conversions are performed. Finally, the ADCTL bits determine whether conversions are performed on  
single or multiple channels.  
3.2.4 Result Registers  
Four 8-bit registers ADR[4:1] store conversion results. Each of these registers can be accessed by the  
processor in the CPU. The conversion complete flag (CCF) indicates when valid data is present in the  
result registers. The result registers are written during a portion of the system clock cycle when reads do  
not occur, so there is no conflict.  
3.2.5 A/D Converter Clocks  
The CSEL bit in the OPTION register selects whether the A/D converter uses the system E clock or an  
internal RC oscillator for synchronization. When E-clock frequency is below 750 kHz, charge leakage in  
the capacitor array can cause errors, and the internal oscillator should be used. When the RC clock is  
used, additional errors can occur because the comparator is sensitive to the additional system clock  
noise.  
3.2.6 Conversion Sequence  
A/D converter operations are performed in sequences of four conversions each. A conversion sequence  
can repeat continuously or stop after one iteration. The conversion complete flag (CCF) is set after the  
fourth conversion in a sequence to show the availability of data in the result registers. Figure 3-3 shows  
the timing of a typical sequence. Synchronization is referenced to the system E clock.  
E CLOCK  
MSB  
4
CYCLES  
BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 LSB  
2
CYC CYC CYC CYC CYC CYC CYC END  
2
CYC  
2
2
2
2
2
2
12 E CYCLES  
SAMPLE ANALOG INPUT  
SUCCESSIVE APPROXIMATION SEQUENCE  
CONVERT FIRST  
CHANNEL, UPDATE  
ADR1  
CONVERT SECOND  
CHANNEL, UPDATE  
ADR2  
CONVERT THIRD  
CHANNEL, UPDATE  
ADR3  
CONVERT FOURTH  
CHANNEL, UPDATE  
ADR4  
0
32  
64  
96  
128 — E CYCLES  
Figure 3-3. A/D Conversion Sequence  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
59  
Analog-to-Digital (A/D) Converter  
3.3 A/D Converter Power-Up and Clock Select  
Bit 7 of the OPTION register controls A/D converter power-up. Clearing ADPU removes power from and  
disables the A/D converter system. Setting ADPU enables the A/D converter system. Stabilization of the  
analog bias voltages requires a delay of as much as 100 µs after turning on the A/D converter. When the  
A/D converter system is operating with the MCU E clock, all switching and comparator operations are  
inherently synchronized to the main MCU clocks. This allows the comparator output to be sampled at  
relatively quiet times during MCU clock cycles. Since the internal RC oscillator is asynchronous to the  
MCU clock, there is more error attributable to internal system clock noise. A/D converter accuracy is  
reduced slightly while the internal RC oscillator is being used (CSEL = 1).  
Address: $1039  
Bit 7  
ADPU  
0
6
CSEL  
0
5
IRQE(1)  
0
4
DLY(1)  
1
3
CME  
0
2
0
1
CR1(1)  
0
Bit 0  
CR0(1)  
0
Read:  
Write:  
Reset:  
1. Can be written only once in first 64 cycles out of reset in normal modes or at any time in special modes  
= Unimplemented  
Figure 3-4. System Configuration Options Register (OPTION)  
ADPU — A/D Power-Up Bit  
0 = A/D powered down  
1 = A/D powered up  
CSEL — Clock Select Bit  
0 = A/D and EEPROM use system E clock.  
1 = A/D and EEPROM use internal RC clock.  
IRQE — Configure IRQ for Edge-Sensitive Only Operation  
Refer to Chapter 5 Resets and Interrupts.  
DLY — Enable Oscillator Startup Delay Bit  
0 = The oscillator startup delay coming out of stop is bypassed and the MCU resumes processing  
within about four bus cycles.  
1 = A delay of approximately 4000 E-clock cycles is imposed as the MCU is started up from the stop  
power-saving mode. This delay allows the crystal oscillator to stabilize.  
CME — Clock Monitor Enable Bit  
Refer to Chapter 5 Resets and Interrupts.  
Bit 2 — Not implemented  
Always reads 0  
CR[1:0] — COP Timer Rate Select Bits  
Refer to Chapter 5 Resets and Interrupts and Chapter 9 Timing Systems.  
M68HC11E Family Data Sheet, Rev. 5.1  
60  
Freescale Semiconductor  
Conversion Process  
3.4 Conversion Process  
The A/D conversion sequence begins one E-clock cycle after a write to the A/D control/status register,  
ADCTL. The bits in ADCTL select the channel and the mode of conversion.  
An input voltage equal to VRL converts to $00 and an input voltage equal to VRH converts to $FF (full  
scale), with no overflow indication. For ratiometric conversions of this type, the source of each analog  
input should use VRH as the supply voltage and be referenced to VRL.  
3.5 Channel Assignments  
The multiplexer allows the A/D converter to select one of 16 analog signals. Eight of these channels  
correspond to port E input lines to the MCU, four of the channels are internal reference points or test  
functions, and four channels are reserved. Refer to Table 3-1.  
Table 3-1. Converter Channel Assignments  
Channel  
Number  
Channel  
Signal  
Result in ADRx  
if MULT = 1  
1
AN0  
AN1  
ADR1  
ADR2  
ADR3  
ADR4  
ADR1  
ADR2  
ADR3  
ADR4  
2
3
AN2  
4
AN3  
5
AN4  
6
AN5  
7
8
AN6  
AN7  
9 – 12  
Reserved  
(1)  
13  
ADR1  
ADR2  
ADR3  
ADR4  
VRH  
(1)  
14  
VRL  
(VRH)/2(1)  
15  
Reserved(1)  
16  
1. Used for factory testing  
3.6 Single-Channel Operation  
The two types of single-channel operation are:  
1. When SCAN = 0, the single selected channel is converted four consecutive times. The first result  
is stored in A/D result register 1 (ADR1), and the fourth result is stored in ADR4. After the fourth  
conversion is complete, all conversion activity is halted until a new conversion command is written  
to the ADCTL register.  
2. When SCAN = 1, conversions continue to be performed on the selected channel with the fifth  
conversion being stored in register ADR1 (overwriting the first conversion result), the sixth  
conversion overwriting ADR2, and so on.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
61  
Analog-to-Digital (A/D) Converter  
3.7 Multiple-Channel Operation  
The two types of multiple-channel operation are:  
1. When SCAN = 0, a selected group of four channels is converted one time each. The first result is  
stored in A/D result register 1 (ADR1), and the fourth result is stored in ADR4. After the fourth  
conversion is complete, all conversion activity is halted until a new conversion command is written  
to the ADCTL register.  
2. When SCAN = 1, conversions continue to be performed on the selected group of channels with the  
fifth conversion being stored in register ADR1 (replacing the earlier conversion result for the first  
channel in the group), the sixth conversion overwriting ADR2, and so on.  
3.8 Operation in Stop and Wait Modes  
If a conversion sequence is in progress when either the stop or wait mode is entered, the conversion of  
the current channel is suspended. When the MCU resumes normal operation, that channel is resampled  
and the conversion sequence is resumed. As the MCU exits wait mode, the A/D circuits are stable and  
valid results can be obtained on the first conversion. However, in stop mode, all analog bias currents are  
disabled and it is necessary to allow a stabilization period when leaving stop mode. If stop mode is exited  
with a delay (DLY = 1), there is enough time for these circuits to stabilize before the first conversion. If  
stop mode is exited with no delay (DLY bit in OPTION register = 0), allow 10 ms for the A/D circuitry to  
stabilize to avoid invalid results.  
3.9 A/D Control/Status Register  
All bits in this register can be read or written, except bit 7, which is a read-only status indicator, and bit 6,  
which always reads as 0. Write to ADCTL to initiate a conversion. To quit a conversion in progress, write  
to this register and a new conversion sequence begins immediately.  
Address: $1030  
Bit 7  
CCF  
6
5
4
3
2
1
Bit 0  
CA  
Read:  
Write:  
Reset:  
SCAN  
MULT  
CD  
CC  
CB  
0
0
Indeterminate after reset  
= Unimplemented  
Figure 3-5. A/D Control/Status Register (ADCTL)  
CCF — Conversion Complete Flag  
A read-only status indicator, this bit is set when all four A/D result registers contain valid conversion  
results. Each time the ADCTL register is overwritten, this bit is automatically cleared to 0 and a  
conversion sequence is started. In the continuous mode, CCF is set at the end of the first conversion  
sequence.  
Bit 6 — Unimplemented  
Always reads 0  
SCAN — Continuous Scan Control Bit  
M68HC11E Family Data Sheet, Rev. 5.1  
62  
Freescale Semiconductor  
A/D Control/Status Register  
When this control bit is clear, the four requested conversions are performed once to fill the four result  
registers. When this control bit is set, conversions are performed continuously with the result registers  
updated as data becomes available.  
MULT — Multiple Channel/Single Channel Control Bit  
When this bit is clear, the A/D converter system is configured to perform four consecutive conversions  
on the single channel specified by the four channel select bits CD:CA (bits [3:0] of the ADCTL register).  
When this bit is set, the A/D system is configured to perform a conversion on each of four channels  
where each result register corresponds to one channel.  
NOTE  
When the multiple-channel continuous scan mode is used, extra care is  
needed in the design of circuitry driving the A/D inputs. The charge on the  
capacitive DAC array before the sample time is related to the voltage on the  
previously converted channel. A charge share situation exists between the  
internal DAC capacitance and the external circuit capacitance. Although  
the amount of charge involved is small, the rate at which it is repeated is  
every 64 µs for an E clock of 2 MHz. The RC charging rate of the external  
circuit must be balanced against this charge sharing effect to avoid errors  
in accuracy. Refer to M68HC11 Reference Manual, Freescale document  
order number M68HC11RM/AD, for further information.  
CD:CA — Channel Selects D:A Bits  
Refer to Table 3-2. When a multiple channel mode is selected (MULT = 1), the two least significant  
channel select bits (CB and CA) have no meaning and the CD and CC bits specify which group of four  
channels is to be converted.  
Table 3-2. A/D Converter Channel Selection  
Channel Select  
Result in ADRx  
Control Bits  
CD:CC:CB:CA  
0000  
Channel Signal  
if MULT = 1  
AN0  
AN1  
ADR1  
ADR2  
ADR3  
ADR4  
ADR1  
ADR2  
ADR3  
ADR4  
0001  
0010  
AN2  
0011  
AN3  
0100  
AN4  
0101  
AN5  
0110  
AN6  
0111  
AN7  
10XX  
Reserved  
(1)  
1100  
1101  
1110  
1111  
ADR1  
ADR2  
ADR3  
ADR4  
VRH  
(1)  
VRL  
(VRH)/2(1)  
Reserved(1)  
1. Used for factory testing  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
63  
Analog-to-Digital (A/D) Converter  
3.10 A/D Converter Result Registers  
These read-only registers hold an 8-bit conversion result. Writes to these registers have no effect. Data  
in the A/D converter result registers is valid when the CCF flag in the ADCTL register is set, indicating a  
conversion sequence is complete. If conversion results are needed sooner, refer to Figure 3-3, which  
shows the A/D conversion sequence diagram.  
Register name: Analog-to-Digital Converter Result Register 1 Address: $1031  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
Reset:  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
Indeterminate after reset  
Register name: Analog-to-Digital Converter Result Register 2 Address: $1032  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
Reset:  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
Indeterminate after reset  
Register name: Analog-to-Digital Converter Result Register 3 Address: $1033  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
Reset:  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
Indeterminate after reset  
Register name: Analog-to-Digital Converter Result Register 4 Address: $1034  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
Reset:  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
Indeterminate after reset  
= Unimplemented  
Figure 3-6. Analog-to-Digital Converter  
Result Registers (ADR1–ADR4)  
M68HC11E Family Data Sheet, Rev. 5.1  
64  
Freescale Semiconductor  
Chapter 4  
Central Processor Unit (CPU)  
4.1 Introduction  
Features of the M68HC11 Family include:  
Central processor unit (CPU) architecture  
Data types  
Addressing modes  
Instruction set  
Special operations such as subroutine calls and interrupts  
The CPU is designed to treat all peripheral, input/output (I/O), and memory locations identically as  
addresses in the 64-Kbyte memory map. This is referred to as memory-mapped I/O. There are no special  
instructions for I/O that are separate from those used for memory. This architecture also allows accessing  
an operand from an external memory location with no execution time penalty.  
4.2 CPU Registers  
M68HC11 CPU registers are an integral part of the CPU and are not addressed as if they were memory  
locations. The seven registers, discussed in the following paragraphs, are shown in Figure 4-1.  
8-BIT ACCUMULATORS A & B  
7
A
0
7
B
0
0
15  
D
OR 16-BIT DOUBLE ACCUMULATOR D  
IX  
INDEX REGISTER X  
INDEX REGISTER Y  
STACK POINTER  
IY  
SP  
PC  
PROGRAM COUNTER  
CONDITION CODES  
7
0
S
X
H
I
N
Z
V
C
CARRY/BORROW FROM MSB  
OVERFLOW  
ZERO  
NEGATIVE  
I-INTERRUPT MASK  
HALF CARRY (FROM BIT 3)  
X-INTERRUPT MASK  
STOP DISABLE  
Figure 4-1. Programming Model  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
65  
Central Processor Unit (CPU)  
4.2.1 Accumulators A, B, and D  
Accumulators A and B are general-purpose 8-bit registers that hold operands and results of arithmetic  
calculations or data manipulations. For some instructions, these two accumulators are treated as a single  
double-byte (16-bit) accumulator called accumulator D. Although most instructions can use accumulators  
A or B interchangeably, these exceptions apply:  
The ABX and ABY instructions add the contents of 8-bit accumulator B to the contents of 16-bit  
register X or Y, but there are no equivalent instructions that use A instead of B.  
The TAP and TPA instructions transfer data from accumulator A to the condition code register or  
from the condition code register to accumulator A. However, there are no equivalent instructions  
that use B rather than A.  
The decimal adjust accumulator A (DAA) instruction is used after binary-coded decimal (BCD)  
arithmetic operations, but there is no equivalent BCD instruction to adjust accumulator B.  
The add, subtract, and compare instructions associated with both A and B (ABA, SBA, and CBA)  
only operate in one direction, making it important to plan ahead to ensure that the correct operand  
is in the correct accumulator.  
4.2.2 Index Register X (IX)  
The IX register provides a 16-bit indexing value that can be added to the 8-bit offset provided in an  
instruction to create an effective address. The IX register can also be used as a counter or as a temporary  
storage register.  
4.2.3 Index Register Y (IY)  
The 16-bit IY register performs an indexed mode function similar to that of the IX register. However, most  
instructions using the IY register require an extra byte of machine code and an extra cycle of execution  
time because of the way the opcode map is implemented. Refer to 4.4 Opcodes and Operands for further  
information.  
4.2.4 Stack Pointer (SP)  
The M68HC11 CPU has an automatic program stack. This stack can be located anywhere in the address  
space and can be any size up to the amount of memory available in the system. Normally, the SP is  
initialized by one of the first instructions in an application program. The stack is configured as a data  
structure that grows downward from high memory to low memory. Each time a new byte is pushed onto  
the stack, the SP is decremented. Each time a byte is pulled from the stack, the SP is incremented. At  
any given time, the SP holds the 16-bit address of the next free location in the stack. Figure 4-2 is a  
summary of SP operations.  
When a subroutine is called by a jump-to-subroutine (JSR) or branch-to- subroutine (BSR) instruction, the  
address of the instruction after the JSR or BSR is automatically pushed onto the stack, least significant  
byte first. When the subroutine is finished, a return-from-subroutine (RTS) instruction is executed. The  
RTS pulls the previously stacked return address from the stack and loads it into the program counter.  
Execution then continues at this recovered return address.  
When an interrupt is recognized, the current instruction finishes normally, the return address (the current  
value in the program counter) is pushed onto the stack, all of the CPU registers are pushed onto the stack,  
and execution continues at the address specified by the vector for the interrupt.  
M68HC11E Family Data Sheet, Rev. 5.1  
66  
Freescale Semiconductor  
CPU Registers  
At the end of the interrupt service routine, an return-from interrupt (RTI) instruction is executed. The RTI  
instruction causes the saved registers to be pulled off the stack in reverse order. Program execution  
resumes at the return address.  
Certain instructions push and pull the A and B accumulators and the X and Y index registers and are often  
used to preserve program context. For example, pushing accumulator A onto the stack when entering a  
subroutine that uses accumulator A and then pulling accumulator A off the stack just before leaving the  
subroutine ensures that the contents of a register will be the same after returning from the subroutine as  
it was before starting the subroutine.  
JSR, JUMP TO SUBROUTINE  
MAIN PROGRAM  
RTI, RETURN FROM INTERRUPT  
STACK  
7
0
INTERRUPT ROUTINE  
PC  
PC  
SP  
SP+1  
SP+2  
SP+3  
SP+4  
SP+5  
SP+6  
SP+7  
SP+8  
È SP+9  
$9D = JSR  
dd  
$3B = RTI  
DIRECT  
INDEXED, X  
INDEXED, Y  
CCR  
ACCB  
ACCA  
IXH  
RTN  
NEXT MAIN INSTR.  
MAIN PROGRAM  
PC  
$AD = JSR  
IXL  
STACK  
ff  
7
0
IYH  
RTN  
NEXT MAIN INSTR.  
È SP–2  
SP–1  
SP  
IYL  
RTNH  
RTNL  
RTNH  
RTNL  
MAIN PROGRAM  
PC  
$18 = PRE  
$AD = JSR  
ff  
SWI, SOFTWARE INTERRUPT  
RTN  
STACK  
7
0
MAIN PROGRAM  
NEXT MAIN INSTR.  
PC  
È SP–9  
SP–8  
SP–7  
SP–6  
SP–5  
SP–4  
SP–3  
SP–2  
SP–1  
SP  
$3F = SWI  
CCR  
ACCB  
ACCA  
IXH  
MAIN PROGRAM  
PC  
$BD = PRE  
hh  
INDEXED, Y  
RTN  
ll  
WAI, WAIT FOR INTERRUPT  
IXL  
NEXT MAIN INSTR.  
MAIN PROGRAM  
IYH  
PC  
IYL  
$3E = WAI  
RTNH  
RTNL  
BSR, BRANCH TO SUBROUTINE  
STACK  
7
0
MAIN PROGRAM  
PC  
È SP–2  
SP–1  
SP  
$8D = BSR  
LEGEND:  
RTNH  
RTNL  
RTN = ADDRESS OF NEXT INSTRUCTION IN MAIN PROGRAM TO  
BE EXECUTED UPON RETURN FROM SUBROUTINE  
RTN = MOST SIGNIFICANT BYTE OF RETURN ADDRESS  
H
RTN = LEAST SIGNIFICANT BYTE OF RETURN ADDRESS  
L
RTS, RETURN FROM  
SUBROUTINE  
È = STACK POINTER POSITION AFTER OPERATION IS COMPLETE  
dd = 8-BIT DIRECT ADDRESS ($0000–$00FF) (HIGH BYTE ASSUMED  
TO BE $00)  
ff = 8-BIT POSITIVE OFFSET $00 (0) TO $FF (255) IS ADDED TO INDEX  
hh = HIGH-ORDER BYTE OF 16-BIT EXTENDED ADDRESS  
ll = LOW-ORDER BYTE OF 16-BIT EXTENDED ADDRESS  
rr= SIGNED RELATIVE OFFSET $80 (–128) TO $7F (+127) (OFFSET  
RELATIVE TO THE ADDRESS FOLLOWING THE MACHINE CODE  
OFFSET BYTE)  
STACK  
7
0
MAIN PROGRAM  
$39 = RTS  
PC  
SP  
SP+1  
RTNH  
RTNL  
È SP+2  
Figure 4-2. Stacking Operations  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
67  
Central Processor Unit (CPU)  
4.2.5 Program Counter (PC)  
The program counter, a 16-bit register, contains the address of the next instruction to be executed. After  
reset, the program counter is initialized from one of six possible vectors, depending on operating mode  
and the cause of reset. See Table 4-1.  
Table 4-1. Reset Vector Comparison  
Mode  
Normal  
POR or RESET Pin  
$FFFE, F  
Clock Monitor  
$FFFC, D  
COP Watchdog  
$FFFA, B  
Test or Boot  
$BFFE, F  
$BFFC, D  
$BFFA, B  
4.2.6 Condition Code Register (CCR)  
This 8-bit register contains:  
Five condition code indicators (C, V, Z, N, and H),  
Two interrupt masking bits (IRQ and XIRQ)  
A stop disable bit (S)  
In the M68HC11 CPU, condition codes are updated automatically by most instructions. For example, load  
accumulator A (LDAA) and store accumulator A (STAA) instructions automatically set or clear the N, Z,  
and V condition code flags. Pushes, pulls, add B to X (ABX), add B to Y (ABY), and transfer/exchange  
instructions do not affect the condition codes. Refer to Table 4-2, which shows what condition codes are  
affected by a particular instruction.  
4.2.6.1 Carry/Borrow (C)  
The C bit is set if the arithmetic logic unit (ALU) performs a carry or borrow during an arithmetic operation.  
The C bit also acts as an error flag for multiply and divide operations. Shift and rotate instructions operate  
with and through the carry bit to facilitate multiple-word shift operations.  
4.2.6.2 Overflow (V)  
The overflow bit is set if an operation causes an arithmetic overflow. Otherwise, the V bit is cleared.  
4.2.6.3 Zero (Z)  
The Z bit is set if the result of an arithmetic, logic, or data manipulation operation is 0. Otherwise, the Z  
bit is cleared. Compare instructions do an internal implied subtraction and the condition codes, including  
Z, reflect the results of that subtraction. A few operations (INX, DEX, INY, and DEY) affect the Z bit and  
no other condition flags. For these operations, only = and conditions can be determined.  
4.2.6.4 Negative (N)  
The N bit is set if the result of an arithmetic, logic, or data manipulation operation is negative (MSB = 1).  
Otherwise, the N bit is cleared. A result is said to be negative if its most significant bit (MSB) is a 1. A quick  
way to test whether the contents of a memory location has the MSB set is to load it into an accumulator  
and then check the status of the N bit.  
M68HC11E Family Data Sheet, Rev. 5.1  
68  
Freescale Semiconductor  
Data Types  
4.2.6.5 Interrupt Mask (I)  
The interrupt request (IRQ) mask (I bit) is a global mask that disables all maskable interrupt sources.  
While the I bit is set, interrupts can become pending, but the operation of the CPU continues uninterrupted  
until the I bit is cleared. After any reset, the I bit is set by default and can only be cleared by a software  
instruction. When an interrupt is recognized, the I bit is set after the registers are stacked, but before the  
interrupt vector is fetched. After the interrupt has been serviced, a return-from-interrupt instruction is  
normally executed, restoring the registers to the values that were present before the interrupt occurred.  
Normally, the I bit is 0 after a return from interrupt is executed. Although the I bit can be cleared within an  
interrupt service routine, "nesting" interrupts in this way should only be done when there is a clear  
understanding of latency and of the arbitration mechanism. Refer to Chapter 5 Resets and Interrupts.  
4.2.6.6 Half Carry (H)  
The H bit is set when a carry occurs between bits 3 and 4 of the arithmetic logic unit during an ADD, ABA,  
or ADC instruction. Otherwise, the H bit is cleared. Half carry is used during BCD operations.  
4.2.6.7 X Interrupt Mask (X)  
The XIRQ mask (X) bit disables interrupts from the XIRQ pin. After any reset, X is set by default and must  
be cleared by a software instruction. When an XIRQ interrupt is recognized, the X and I bits are set after  
the registers are stacked, but before the interrupt vector is fetched. After the interrupt has been serviced,  
an RTI instruction is normally executed, causing the registers to be restored to the values that were  
present before the interrupt occurred. The X interrupt mask bit is set only by hardware (RESET or XIRQ  
acknowledge). X is cleared only by program instruction (TAP, where the associated bit of A is 0; or RTI,  
where bit 6 of the value loaded into the CCR from the stack has been cleared). There is no hardware  
action for clearing X.  
4.2.6.8 STOP Disable (S)  
Setting the STOP disable (S) bit prevents the STOP instruction from putting the M68HC11 into a  
low-power stop condition. If the STOP instruction is encountered by the CPU while the S bit is set, it is  
treated as a no-operation (NOP) instruction, and processing continues to the next instruction. S is set by  
reset; STOP is disabled by default.  
4.3 Data Types  
The M68HC11 CPU supports four data types:  
1. Bit data  
2. 8-bit and 16-bit signed and unsigned integers  
3. 16-bit unsigned fractions  
4. 16-bit addresses  
A byte is eight bits wide and can be accessed at any byte location. A word is composed of two consecutive  
bytes with the most significant byte at the lower value address. Because the M68HC11 is an 8-bit CPU,  
there are no special requirements for alignment of instructions or operands.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
69  
Central Processor Unit (CPU)  
4.4 Opcodes and Operands  
The M68HC11 Family of microcontrollers uses 8-bit opcodes. Each opcode identifies a particular  
instruction and associated addressing mode to the CPU. Several opcodes are required to provide each  
instruction with a range of addressing capabilities. Only 256 opcodes would be available if the range of  
values were restricted to the number able to be expressed in 8-bit binary numbers.  
A 4-page opcode map has been implemented to expand the number of instructions. An additional byte,  
called a prebyte, directs the processor from page 0 of the opcode map to one of the other three pages.  
As its name implies, the additional byte precedes the opcode.  
A complete instruction consists of a prebyte, if any, an opcode, and zero, one, two, or three operands.  
The operands contain information the CPU needs for executing the instruction. Complete instructions can  
be from one to five bytes long.  
4.5 Addressing Modes  
Six addressing modes can be used to access memory:  
Immediate  
Direct  
Extended  
Indexed  
Inherent  
Relative  
These modes are detailed in the following paragraphs. All modes except inherent mode use an effective  
address. The effective address is the memory address from which the argument is fetched or stored or  
the address from which execution is to proceed. The effective address can be specified within an  
instruction, or it can be calculated.  
4.5.1 Immediate  
In the immediate addressing mode, an argument is contained in the byte(s) immediately following the  
opcode. The number of bytes following the opcode matches the size of the register or memory location  
being operated on. There are 2-, 3-, and 4- (if prebyte is required) byte immediate instructions. The  
effective address is the address of the byte following the instruction.  
4.5.2 Direct  
In the direct addressing mode, the low-order byte of the operand address is contained in a single byte  
following the opcode, and the high-order byte of the address is assumed to be $00. Addresses $00–$FF  
are thus accessed directly, using 2-byte instructions. Execution time is reduced by eliminating the  
additional memory access required for the high-order address byte. In most applications, this  
256-byte area is reserved for frequently referenced data. In M68HC11 MCUs, the memory map can be  
configured for combinations of internal registers, RAM, or external memory to occupy these addresses.  
M68HC11E Family Data Sheet, Rev. 5.1  
70  
Freescale Semiconductor  
Instruction Set  
4.5.3 Extended  
In the extended addressing mode, the effective address of the argument is contained in two bytes  
following the opcode byte. These are 3-byte instructions (or 4-byte instructions if a prebyte is required).  
One or two bytes are needed for the opcode and two for the effective address.  
4.5.4 Indexed  
In the indexed addressing mode, an 8-bit unsigned offset contained in the instruction is added to the value  
contained in an index register (IX or IY). The sum is the effective address. This addressing mode allows  
referencing any memory location in the 64-Kbyte address space. These are 2- to 5-byte instructions,  
depending on whether or not a prebyte is required.  
4.5.5 Inherent  
In the inherent addressing mode, all the information necessary to execute the instruction is contained in  
the opcode. Operations that use only the index registers or accumulators, as well as control instructions  
with no arguments, are included in this addressing mode. These are  
1- or 2-byte instructions.  
4.5.6 Relative  
The relative addressing mode is used only for branch instructions. If the branch condition is true, an 8-bit  
signed offset included in the instruction is added to the contents of the program counter to form the  
effective branch address. Otherwise, control proceeds to the next instruction. These are usually 2-byte  
instructions.  
4.6 Instruction Set  
Refer to Table 4-2, which shows all the M68HC11 instructions in all possible addressing modes. For each  
instruction, the table shows the operand construction, the number of machine code bytes, and execution  
time in CPU E-clock cycles.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
71  
Central Processor Unit (CPU)  
Table 4-2. Instruction Set (Sheet 1 of 7)  
Addressing  
Mode  
Instruction  
Operand Cycles  
Condition Codes  
Mnemonic  
Operation  
Description  
Opcode  
S
X
H
I
N
Z
V
C
ABA  
Add  
Accumulators  
A + B A  
INH  
1B  
2
ABX  
ABY  
ADCA (opr)  
Add B to X  
Add B to Y  
Add with Carry  
to A  
IX + (00 : B) IX  
IY + (00 : B) IY  
A + M + C A  
INH  
INH  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
EXT  
3A  
3A  
89  
99  
3
4
2
3
4
4
5
2
3
4
4
5
2
3
4
4
5
2
3
4
4
5
4
5
6
6
7
2
3
4
4
5
2
3
4
4
5
18  
18  
18  
18  
18  
18  
18  
A
A
A
A
A
B
B
B
B
B
A
A
A
A
A
B
B
B
B
B
ii  
dd  
B9 hh ll  
A9  
A9  
C9 ii  
D9 dd  
F9 hh ll  
E9  
E9  
8B  
9B  
BB hh ll  
AB ff  
AB ff  
CB ii  
DB dd  
FB hh ll  
EB ff  
EB ff  
C3 jj kk  
D3 dd  
F3 hh ll  
ff  
ff  
ADCB (opr)  
ADDA (opr)  
ADDB (opr)  
ADDD (opr)  
ANDA (opr)  
ANDB (opr)  
Add with Carry  
to B  
B + M + C B  
A + M A  
0
0
ff  
ff  
Add Memory to  
A
ii  
dd  
Add Memory to  
B
B + M B  
Add 16-Bit to D D + (M : M + 1) D  
E3  
E3  
84  
94  
ff  
ff  
AND A with  
Memory  
A • M A  
B • M B  
A
A
A
A
A
B
B
B
B
B
ii  
dd  
B4 hh ll  
A4  
A4  
C4 ii  
D4 dd  
F4 hh ll  
E4  
E4  
78  
68  
68  
ff  
ff  
AND B with  
Memory  
ff  
ff  
18  
18  
ASL (opr)  
ASLA  
Arithmetic Shift  
Left  
hh ll  
ff  
6
6
7
IND,X  
IND,Y  
0
ff  
b7  
b0  
C
Arithmetic Shift  
Left A  
A
B
INH  
INH  
INH  
48  
58  
05  
2
2
3
0
0
b7  
b7  
b0  
b0  
C
C
ASLB  
ASLD  
Arithmetic Shift  
Left B  
Arithmetic Shift  
Left D  
0
b7 A b0 b7 B b0  
C
ASR  
Arithmetic Shift  
Right  
EXT  
IND,X  
IND,Y  
INH  
INH  
REL  
77  
67  
67  
hh ll  
ff  
6
6
7
2
2
3
18  
ff  
b7  
b7  
b7  
b0  
b0  
b0  
C
ASRA  
ASRB  
BCC (rel)  
Arithmetic Shift  
Right A  
A
B
47  
C
C
Arithmetic Shift  
Right B  
57  
Branch if Carry  
Clear  
Clear Bit(s)  
? C = 0  
24  
15  
rr  
0
BCLR (opr)  
(msk)  
M • (mm) M  
DIR  
IND,X  
IND,Y  
dd mm  
6
7
8
1D ff mm  
1D ff mm  
18  
BCS (rel)  
Branch if Carry  
Set  
Branch if = Zero  
? C = 1  
REL  
25  
27  
rr  
3
BEQ (rel)  
BGE (rel)  
? Z = 1  
? N V = 0  
REL  
REL  
rr  
3
3
Branch if Zero  
2C rr  
M68HC11E Family Data Sheet, Rev. 5.1  
72  
Freescale Semiconductor  
Instruction Set  
Table 4-2. Instruction Set (Sheet 2 of 7)  
Addressing  
Mode  
Instruction  
Operand Cycles  
Condition Codes  
Mnemonic  
Operation  
Description  
Opcode  
2E  
S
X
H
I
N
Z
V
C
BGT (rel)  
BHI (rel)  
Branch if > Zero  
? Z + (N V) = 0  
? C + Z = 0  
REL  
REL  
rr  
rr  
3
3
Branch if  
Higher  
22  
BHS (rel)  
Branch if  
Higher or Same  
Bit(s) Test A  
with Memory  
? C = 0  
A • M  
REL  
24  
rr  
3
0
BITA (opr)  
A
A
A
A
A
B
B
B
B
B
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
85  
95  
ii  
dd  
2
3
4
4
5
2
3
4
4
5
B5 hh ll  
A5  
A5  
C5 ii  
D5 dd  
F5 hh ll  
E5  
E5  
ff  
ff  
18  
18  
BITB (opr)  
Bit(s) Test B  
with Memory  
B • M  
0
ff  
ff  
BLE (rel)  
BLO (rel)  
BLS (rel)  
Branch if Zero  
Branch if Lower  
Branch if Lower  
or Same  
? Z + (N V) = 1  
? C = 1  
? C + Z = 1  
REL  
REL  
REL  
2F  
25  
23  
rr  
rr  
rr  
3
3
3
BLT (rel)  
BMI (rel)  
BNE (rel)  
Branch if < Zero  
Branch if Minus  
Branch if not =  
Zero  
? N V = 1  
? N = 1  
? Z = 0  
REL  
REL  
REL  
2D rr  
3
3
3
2B  
26  
rr  
rr  
BPL (rel)  
BRA (rel)  
BRCLR(opr)  
(msk)  
Branch if Plus  
Branch Always  
Branch if  
? N = 0  
? 1 = 1  
? M • mm = 0  
REL  
REL  
DIR  
IND,X  
IND,Y  
2A  
20  
13  
1F  
1F  
rr  
rr  
3
3
6
7
8
dd mm  
rr  
ff mm  
rr  
Bit(s) Clear  
(rel)  
18  
ff mm  
rr  
BRN (rel)  
BRSET(opr)  
(msk)  
Branch Never  
Branch if Bit(s)  
Set  
? 1 = 0  
? (M) • mm = 0  
REL  
DIR  
IND,X  
IND,Y  
21  
rr  
3
12  
1E  
1E  
dd mm  
rr  
ff mm  
rr  
ff mm  
rr  
6
7
8
(rel)  
18  
18  
BSET (opr)  
(msk)  
Set Bit(s)  
M + mm M  
DIR  
IND,X  
IND,Y  
14  
dd mm  
6
7
8
0
1C ff mm  
1C ff mm  
BSR (rel)  
BVC (rel)  
BVS (rel)  
Branch to  
Subroutine  
Branch if  
Overflow Clear  
Branch if  
Overflow Set  
See Figure 3–2  
? V = 0  
REL  
REL  
REL  
8D rr  
6
3
3
28  
29  
rr  
rr  
? V = 1  
CBA  
CLC  
CLI  
Compare A to B  
Clear Carry Bit  
Clear Interrupt  
Mask  
A – B  
0 C  
0 I  
INH  
INH  
INH  
11  
0C  
0E  
2
2
2
0
0
CLR (opr)  
Clear Memory  
Byte  
0 M  
EXT  
IND,X  
IND,Y  
7F  
6F  
6F  
hh ll  
ff  
ff  
6
6
7
0
1
0
0
18  
CLRA  
CLRB  
Clear  
Accumulator A  
Clear  
Accumulator B  
Clear Overflow  
Flag  
Compare A to  
Memory  
0 A  
0 B  
0 V  
A – M  
A
B
INH  
INH  
INH  
4F  
5F  
0A  
2
2
2
0
0
1
1
0
0
0
0
0
CLV  
CMPA (opr)  
A
A
A
A
A
IMM  
DIR  
EXT  
IND,X  
IND,Y  
81  
91  
ii  
dd  
2
3
4
4
5
B1 hh ll  
A1  
A1  
ff  
ff  
18  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
73  
Central Processor Unit (CPU)  
Table 4-2. Instruction Set (Sheet 3 of 7)  
Addressing  
Mode  
Instruction  
Operand Cycles  
Condition Codes  
Mnemonic  
Operation  
Description  
Opcode  
C1 ii  
S
X
H
I
N
Z
V
C
CMPB (opr)  
Compare B to  
Memory  
B – M  
B
B
B
B
B
IMM  
DIR  
EXT  
IND,X  
IND,Y  
EXT  
IND,X  
IND,Y  
INH  
INH  
2
3
4
4
5
D1 dd  
F1 hh ll  
E1  
E1  
73  
63  
63  
ff  
ff  
18  
18  
COM (opr)  
COMA  
Ones  
Complement  
Memory Byte  
Ones  
Complement  
A
Ones  
Complement  
B
$FF – M M  
$FF – A A  
$FF – B B  
D – M : M + 1  
hh ll  
ff  
ff  
6
6
7
0
0
0
1
1
1
A
B
43  
2
COMB  
53  
2
CPD (opr)  
Compare D to  
Memory 16-Bit  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
1A  
1A  
1A  
1A  
CD  
83  
93  
B3  
A3  
A3  
jj kk  
dd  
hh ll  
ff  
5
6
7
7
7
ff  
CPX (opr)  
CPY (opr)  
Compare X to  
Memory 16-Bit  
IX – M : M + 1  
IY – M : M + 1  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
8C jj kk  
9C dd  
BC hh ll  
AC ff  
AC ff  
8C jj kk  
9C dd  
BC hh ll  
AC ff  
4
5
6
6
7
5
6
7
7
7
CD  
Compare Y to  
Memory 16-Bit  
18  
18  
18  
1A  
18  
IND,Y  
AC ff  
DAA  
Decimal Adjust Adjust Sum to BCD  
A
INH  
19  
2
DEC (opr)  
Decrement  
M – 1 M  
A – 1 A  
B – 1 B  
EXT  
IND,X  
IND,Y  
INH  
INH  
7A  
6A  
6A  
hh ll  
ff  
6
6
7
Memory Byte  
18  
ff  
DECA  
DECB  
Decrement  
Accumulator  
A
A
B
4A  
2
Decrement  
Accumulator  
B
5A  
2
DES  
DEX  
Decrement  
Stack Pointer  
Decrement  
Index Register  
X
SP – 1 SP  
IX – 1 IX  
INH  
INH  
34  
09  
3
3
DEY  
Decrement  
Index Register  
Y
Exclusive OR A  
with Memory  
IY – 1 IY  
A M A  
INH  
18  
09  
4
0
EORA (opr)  
A
A
A
A
A
B
B
B
B
B
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
88  
98  
ii  
dd  
2
3
4
4
5
2
3
4
4
5
B8 hh ll  
A8  
A8  
C8 ii  
D8 dd  
F8 hh ll  
E8  
E8  
ff  
ff  
18  
18  
EORB (opr)  
Exclusive OR B  
with Memory  
B M B  
0
ff  
ff  
IND,Y  
FDIV  
IDIV  
Fractional  
Divide 16 by 16  
Integer Divide  
16 by 16  
Increment  
D / IX IX; r D  
D / IX IX; r D  
M + 1 M  
INH  
INH  
03  
02  
41  
0
41  
INC (opr)  
EXT  
IND,X  
IND,Y  
7C hh ll  
6C ff  
6C ff  
6
6
7
Memory Byte  
18  
INCA  
Increment  
Accumulator  
A
A + 1 A  
A
INH  
4C  
2
M68HC11E Family Data Sheet, Rev. 5.1  
74  
Freescale Semiconductor  
Instruction Set  
Table 4-2. Instruction Set (Sheet 4 of 7)  
Addressing  
Mode  
Instruction  
Operand Cycles  
Condition Codes  
Mnemonic  
Operation  
Description  
Opcode  
S
X
H
I
N
Z
V
C
INCB  
Increment  
Accumulator  
B
B + 1 B  
B
INH  
5C  
2
INS  
INX  
Increment  
Stack Pointer  
Increment  
Index Register  
X
SP + 1 SP  
IX + 1 IX  
INH  
INH  
31  
08  
3
3
INY  
Increment  
Index Register  
Y
IY + 1 IY  
See Figure 3–2  
See Figure 3–2  
INH  
18  
08  
4
JMP (opr)  
JSR (opr)  
Jump  
EXT  
IND,X  
IND,Y  
DIR  
EXT  
IND,X  
IND,Y  
7E  
6E  
6E  
hh ll  
ff  
3
3
4
5
6
6
7
18  
18  
ff  
Jump to  
Subroutine  
9D dd  
BD hh ll  
AD ff  
AD ff  
LDAA (opr)  
LDAB (opr)  
LDD (opr)  
LDS (opr)  
LDX (opr)  
LDY (opr)  
Load  
Accumulator  
A
M A  
A
A
A
A
A
B
B
B
B
B
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
86  
96  
ii  
dd  
2
3
4
4
5
2
3
4
4
5
3
4
5
5
6
3
4
5
5
6
3
4
5
5
6
4
5
6
6
6
0
0
0
0
0
0
B6 hh ll  
A6  
A6  
C6 ii  
D6 dd  
F6 hh ll  
E6  
E6  
CC jj kk  
DC dd  
FC hh ll  
EC ff  
EC ff  
8E  
9E  
BE hh ll  
AE ff  
AE ff  
CE jj kk  
DE dd  
FE hh ll  
EE ff  
EE ff  
CE jj kk  
DE dd  
FE hh ll  
ff  
ff  
18  
18  
18  
18  
CD  
Load  
Accumulator  
B
M B  
ff  
ff  
Load Double  
Accumulator  
D
M A,M + 1 B  
M : M + 1 SP  
M : M + 1 IX  
M : M + 1 IY  
Load Stack  
Pointer  
jj kk  
dd  
Load Index  
Register  
X
Load Index  
Register  
Y
18  
18  
18  
1A  
18  
EXT  
IND,X  
IND,Y  
EE ff  
EE ff  
LSL (opr)  
LSLA  
Logical Shift  
Left  
EXT  
IND,X  
IND,Y  
INH  
INH  
INH  
78  
68  
68  
48  
58  
05  
hh ll  
ff  
ff  
6
6
7
2
2
3
0
0
0
0
18  
b7  
b7  
b7  
b0  
b0  
b0  
C
C
C
Logical Shift  
Left A  
A
B
0
0
LSLB  
Logical Shift  
Left B  
LSLD  
Logical Shift  
Left Double  
0
b7 A b0 b7 B b0  
C
LSR (opr)  
LSRA  
Logical Shift  
Right  
EXT  
IND,X  
IND,Y  
INH  
INH  
74  
64  
64  
hh ll  
ff  
ff  
6
6
7
0
0
0
18  
b7  
b7  
b7  
b0  
b0  
b0  
C
C
C
Logical Shift  
Right A  
A
B
44  
2
LSRB  
Logical Shift  
Right B  
54  
2
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
75  
Central Processor Unit (CPU)  
Table 4-2. Instruction Set (Sheet 5 of 7)  
Addressing  
Mode  
Instruction  
Operand Cycles  
Condition Codes  
Mnemonic  
Operation  
Description  
Opcode  
S
X
H
I
N
Z
V
C
LSRD  
Logical Shift  
Right Double  
INH  
04  
3
0
0
b7 A b0 b7 B b0  
C
MUL  
NEG (opr)  
Multiply 8 by 8  
A B D  
INH  
EXT  
IND,X  
IND,Y  
INH  
INH  
INH  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
3D  
hh ll  
ff  
10  
Two’s  
Complement  
Memory Byte  
Two’s  
Complement  
A
Two’s  
Complement  
B
0 – M M  
0 – A A  
0 – B B  
70  
60  
60  
40  
50  
01  
6
6
7
2
2
2
2
3
4
4
5
2
3
4
4
5
18  
ff  
NEGA  
NEGB  
A
B
NOP  
ORAA (opr)  
No operation  
No Operation  
A + M A  
0
OR  
Accumulator  
A (Inclusive)  
A
A
A
A
A
B
B
B
B
B
8A  
9A  
ii  
dd  
BA hh ll  
AA ff  
AA ff  
CA ii  
DA dd  
FA hh ll  
EA ff  
18  
18  
ORAB (opr)  
OR  
Accumulator  
B (Inclusive)  
B + M B  
0
IND,Y  
EA ff  
PSHA  
PSHB  
PSHX  
Push A onto  
Stack  
Push B onto  
Stack  
Push X onto IX Stk,SP = SP – 2  
Stack (Lo  
First)  
A Stk,SP = SP – 1  
B Stk,SP = SP – 1  
A
INH  
INH  
INH  
36  
37  
3C  
3
3
4
B
PSHY  
Push Y onto IY Stk,SP = SP – 2  
Stack (Lo  
First)  
INH  
18  
3C  
5
PULA  
PULB  
PULX  
Pull A from  
Stack  
Pull B from  
Stack  
Pull X From SP = SP + 2, IX Stk  
Stack (Hi  
First)  
SP = SP + 1, A Stk A  
SP = SP + 1, B Stk B  
INH  
INH  
INH  
32  
33  
38  
4
4
5
PULY  
ROL (opr)  
ROLA  
Pull Y from  
Stack (Hi  
First)  
SP = SP + 2, IY Stk  
INH  
18  
18  
38  
6
Rotate Left  
Rotate Left A  
Rotate Left B  
Rotate Right  
Rotate Right A  
Rotate Right B  
EXT  
IND,X  
IND,Y  
INH  
INH  
79  
69  
69  
hh ll  
ff  
6
6
7
ff  
b7  
b7  
b7  
b0  
b0  
b0  
C
A
B
49  
2
C
ROLB  
59  
2
C
ROR (opr)  
RORA  
EXT  
IND,X  
IND,Y  
76  
66  
66  
hh ll  
ff  
6
6
7
b7  
b0  
b0  
b0  
C
18  
ff  
A
B
INH  
46  
2
b7  
b7  
C
C
RORB  
INH  
56  
2
RTI  
RTS  
SBA  
Return from  
Interrupt  
Return from  
Subroutine  
Subtract B from  
A
See Figure 3–2  
See Figure 3–2  
A – B A  
INH  
INH  
INH  
3B  
39  
10  
12  
5
2
M68HC11E Family Data Sheet, Rev. 5.1  
76  
Freescale Semiconductor  
Instruction Set  
Table 4-2. Instruction Set (Sheet 6 of 7)  
Addressing  
Mode  
Instruction  
Operand Cycles  
Condition Codes  
Mnemonic  
Operation  
Description  
Opcode  
S
X
H
I
N
Z
V
C
SBCA (opr)  
Subtract with  
Carry from A  
A – M – C A  
A
A
A
A
A
B
B
B
B
B
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
82  
92  
ii  
dd  
2
3
4
4
5
2
3
4
4
5
B2 hh ll  
A2  
A2  
C2 ii  
D2 dd  
F2 hh ll  
E2  
E2  
ff  
ff  
18  
18  
SBCB (opr)  
Subtract with  
Carry from B  
B – M – C B  
IND,X  
IND,Y  
ff  
ff  
SEC  
SEI  
Set Carry  
Set Interrupt  
Mask  
1 C  
1 I  
INH  
INH  
0D  
0F  
2
2
1
1
SEV  
Set Overflow  
Flag  
Store  
Accumulator  
A
1 V  
INH  
0B  
2
1
0
STAA (opr)  
A M  
A
A
A
A
B
B
B
B
DIR  
EXT  
IND,X  
IND,Y  
DIR  
EXT  
IND,X  
IND,Y  
DIR  
97  
B7  
A7 ff  
A7 ff  
D7 dd  
F7  
E7 ff  
E7 ff  
DD dd  
dd  
3
4
4
5
3
4
4
5
4
5
5
6
hh ll  
18  
18  
18  
STAB (opr)  
STD (opr)  
Store  
Accumulator  
B
B M  
0
0
hh ll  
Store  
Accumulator  
D
A M, B M + 1  
EXT  
IND,X  
IND,Y  
FD hh ll  
ED ff  
ED ff  
STOP  
Stop Internal  
Clocks  
Store Stack  
Pointer  
INH  
CF  
2
0
STS (opr)  
SP M : M + 1  
DIR  
EXT  
IND,X  
IND,Y  
9F  
dd  
4
5
5
6
BF hh ll  
AF ff  
AF ff  
18  
STX (opr)  
STY (opr)  
SUBA (opr)  
Store Index  
Register X  
IX M : M + 1  
IY M : M + 1  
A – M A  
DIR  
EXT  
IND,X  
IND,Y  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DIR  
EXT  
IND,X  
IND,Y  
IMM  
DF dd  
4
5
5
6
5
6
6
6
2
3
4
4
5
2
3
4
4
5
0
0
FF  
hh ll  
EF ff  
EF ff  
DF dd  
CD  
Store Index  
Register Y  
18  
18  
1A  
18  
FF  
hh ll  
EF ff  
EF ff  
Subtract  
Memory from  
A
A
A
A
A
A
A
A
A
A
A
80  
90  
ii  
dd  
B0 hh ll  
A0  
A0  
ff  
ff  
18  
18  
18  
SUBB (opr)  
SUBD (opr)  
SWI  
Subtract  
Memory from  
B
B – M B  
C0 ii  
D0 dd  
F0 hh ll  
1
E0  
E0  
ff  
ff  
Subtract  
Memory from  
D
D – M : M + 1 D  
See Figure 3–2  
83  
93  
jj kk  
dd  
4
5
6
6
7
DIR  
EXT  
IND,X  
IND,Y  
INH  
B3 hh ll  
A3  
A3  
ff  
ff  
Software  
Interrupt  
3F  
14  
TAB  
TAP  
Transfer A to B  
Transfer A to  
CC Register  
A B  
A CCR  
INH  
INH  
16  
06  
2
2
0
TBA  
TEST  
Transfer B to A  
TEST (Only in Address Bus Counts  
Test Modes)  
B A  
INH  
INH  
17  
00  
2
*
0
TPA  
Transfer CC  
Register to A  
Test for Zero or  
Minus  
CCR A  
INH  
07  
2
0
0
TST (opr)  
M – 0  
EXT  
IND,X  
IND,Y  
7D hh ll  
6D ff  
6D ff  
6
6
7
18  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
77  
Central Processor Unit (CPU)  
Table 4-2. Instruction Set (Sheet 7 of 7)  
Addressing  
Mode  
Instruction  
Operand Cycles  
Condition Codes  
Mnemonic  
Operation  
Description  
Opcode  
S
X
H
I
N
Z
V
C
TSTA  
Test A for Zero  
or Minus  
Test B for Zero  
or Minus  
Transfer Stack  
Pointer to X  
Transfer Stack  
Pointer to Y  
Transfer X to  
Stack Pointer  
Transfer Y to  
Stack Pointer  
Wait for  
Interrupt  
Exchange D  
with X  
A – 0  
A
B
INH  
4D  
2
2
3
4
3
4
**  
3
4
0
0
TSTB  
TSX  
B – 0  
INH  
INH  
INH  
INH  
INH  
INH  
INH  
INH  
5D  
30  
30  
35  
35  
3E  
8F  
8F  
0
0
SP + 1 IX  
TSY  
SP + 1 IY  
18  
18  
TXS  
IX – 1 SP  
TYS  
IY – 1 SP  
WAI  
Stack Regs & WAIT  
IX D, D IX  
IY D, D IY  
XGDX  
XGDY  
Exchange D  
with Y  
18  
Cycle  
*
Infinity or until reset occurs  
**  
12 cycles are used beginning with the opcode fetch. A wait state is entered which remains in effect for an integer number of MPU E-clock  
cycles (n) until an interrupt is recognized. Finally, two additional cycles are used to fetch the appropriate interrupt vector (14 + n total).  
Operands  
dd  
ff  
hh  
ii  
jj  
kk  
ll  
mm  
rr  
= 8-bit direct address ($0000–$00FF) (high byte assumed to be $00)  
= 8-bit positive offset $00 (0) to $FF (255) (is added to index)  
= High-order byte of 16-bit extended address  
= One byte of immediate data  
= High-order byte of 16-bit immediate data  
= Low-order byte of 16-bit immediate data  
= Low-order byte of 16-bit extended address  
= 8-bit mask (set bits to be affected)  
= Signed relative offset $80 (–128) to $7F (+127)  
(offset relative to address following machine code offset byte))  
Operators  
Condition Codes  
( )  
Contents of register shown inside parentheses  
0
Bit not changed  
Is transferred to  
Bit always cleared  
Is pulled from stack  
Is pushed onto stack  
Boolean AND  
1
Bit always set  
Bit cleared or set, depending on operation  
Bit can be cleared, cannot become set  
+
Arithmetic addition symbol except where used as inclusive-OR symbol  
in Boolean formula  
:
Exclusive-OR  
Multiply  
Concatenation  
Arithmetic subtraction symbol or negation symbol (two’s complement)  
M68HC11E Family Data Sheet, Rev. 5.1  
78  
Freescale Semiconductor  
Chapter 5  
Resets and Interrupts  
5.1 Introduction  
Resets and interrupt operations load the program counter with a vector that points to a new location from  
which instructions are to be fetched. A reset immediately stops execution of the current instruction and  
forces the program counter to a known starting address. Internal registers and control bits are initialized  
so the MCU can resume executing instructions. An interrupt temporarily suspends normal program  
execution while an interrupt service routine is being executed. After an interrupt has been serviced, the  
main program resumes as if there had been no interruption.  
5.2 Resets  
The four possible sources of reset are:  
Power-on reset (POR)  
External reset (RESET)  
Computer operating properly (COP) reset  
Clock monitor reset  
POR and RESET share the normal reset vector. COP reset and the clock monitor reset each has its own  
vector.  
5.2.1 Power-On Reset (POR)  
A positive transition on VDD generates a power-on reset (POR), which is used only for power-up  
conditions. POR cannot be used to detect drops in power supply voltages. A 4064 tCYC (internal clock  
cycle) delay after the oscillator becomes active allows the clock generator to stabilize. If RESET is at  
logical 0 at the end of 4064 tCYC, the CPU remains in the reset condition until RESET goes to logical 1.  
The POR circuit only initializes internal circuitry during cold starts. Refer to  
Figure 1-7. External Reset Circuit.  
NOTE  
It is important to protect the MCU during power transitions. Most M68HC11  
systems need an external circuit that holds the RESET pin low whenever  
VDD is below the minimum operating level. This external voltage level  
detector, or other external reset circuits, are the usual source of reset in a  
system.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
79  
Resets and Interrupts  
5.2.2 External Reset (RESET)  
The CPU distinguishes between internal and external reset conditions by sensing whether the reset pin  
rises to a logic 1 in less than two E-clock cycles after an internal device releases reset. When a reset  
condition is sensed, the RESET pin is driven low by an internal device for four E-clock cycles, then  
released. Two E-clock cycles later it is sampled. If the pin is still held low, the CPU assumes that an  
external reset has occurred. If the pin is high, it indicates that the reset was initiated internally by either  
the COP system or the clock monitor.  
CAUTION  
Do not connect an external resistor capacitor (RC) power-up delay circuit to the reset pin of M68HC11  
devices because the circuit charge time constant can cause the device to misinterpret the type of reset  
that occurred.  
5.2.3 Computer Operating Properly (COP) Reset  
The MCU includes a COP system to help protect against software failures. When the COP is enabled, the  
software is responsible for keeping a free-running watchdog timer from timing out. When the software is  
no longer being executed in the intended sequence, a system reset is initiated.  
The state of the NOCOP bit in the CONFIG register determines whether the COP system is enabled or  
disabled. To change the enable status of the COP system, change the contents of the CONFIG register  
and then perform a system reset. In the special test and bootstrap operating modes, the COP system is  
initially inhibited by the disable resets (DISR) control bit in the TEST1 register. The DISR bit can  
subsequently be written to 0 to enable COP resets.  
The COP timer rate control bits CR[1:0] in the OPTION register determine the COP timeout period. The  
system E clock is divided by 215 and then further scaled by a factor shown in Table 5-1. After reset, these  
bits are 0, which selects the fastest timeout period. In normal operating modes, these bits can be written  
only once within 64 bus cycles after reset.  
Table 5-1. COP Timer Rate Select  
XTAL = 4.0 MHz  
Timeout  
XTAL = 8.0 MHz XTAL = 12.0 MHz XTAL = 16.0 MHz  
Timeout Timeout Timeout  
Divide  
E/215 By  
CR[1:0]  
– 0 ms, + 32.8 ms – 0 ms, + 16.4 ms – 0 ms, + 10.9 ms – 0 ms, + 8.2 ms  
0 0  
0 1  
1 0  
1 1  
1
4
32.768 ms  
131.072 ms  
524.28 ms  
2.098 s  
16.384 ms  
65.536 ms  
262.14 ms  
1.049 s  
10.923 ms  
43.691 ms  
174.76 ms  
699.05 ms  
3.0 MHz  
8.19 ms  
32.8 ms  
131 ms  
524 ms  
4.0 MHz  
16  
64  
E =  
1.0 MHz  
2.0 MHz  
M68HC11E Family Data Sheet, Rev. 5.1  
80  
Freescale Semiconductor  
Resets  
Address  
$103A  
Bit 7  
6
BIT 6  
0
5
BIT 5  
0
4
BIT 4  
0
3
BIT 3  
0
2
BIT 2  
0
1
BIT 1  
0
Bit 0  
BIT 0  
0
Read:  
Write:  
Reset:  
BIT 7  
0
Figure 5-1. Arm/Reset COP Timer Circuitry Register (COPRST)  
Complete this 2-step reset sequence to service the COP timer:  
1. Write $55 to COPRST to arm the COP timer clearing mechanism.  
2. Write $AA to COPRST to clear the COP timer.  
Performing instructions between these two steps is possible as long  
as both steps are completed in the correct sequence before the timer times out.  
5.2.4 Clock Monitor Reset  
The clock monitor circuit is based on an internal resistor capacitor (RC) time delay. If no MCU clock edges  
are detected within this RC time delay, the clock monitor can optionally generate a system reset. The  
clock monitor function is enabled or disabled by the CME control bit in the OPTION register. The presence  
of a timeout is determined by the RC delay, which allows the clock monitor to operate without any MCU  
clocks.  
Clock monitor is used as a backup for the COP system. Because the COP needs a clock to function, it is  
disabled when the clock stops. Therefore, the clock monitor system can detect clock failures not detected  
by the COP system.  
Semiconductor wafer processing causes variations of the RC timeout values between individual devices.  
An E-clock frequency below 10 kHz is detected as a clock monitor error. An E-clock frequency of 200 kHz  
or more prevents clock monitor errors. Using the clock monitor function when the E-clock is below 200  
kHz is not recommended.  
Special considerations are needed when a STOP instruction is executed and the clock monitor is enabled.  
Because the STOP function causes the clocks to be halted, the clock monitor function generates a reset  
sequence if it is enabled at the time the stop mode was initiated. Before executing a STOP instruction,  
clear the CME bit in the OPTION register to 0 to disable the clock monitor. After recovery from STOP, set  
the CME bit to logic 1 to enable the clock monitor. Alternatively, executing a STOP instruction with the  
CME bit set to logic 1 can be used as a software initiated reset.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
81  
Resets and Interrupts  
5.2.5 System Configuration Options Register  
Address:  
$1039  
Bit 7  
6
CSEL  
0
5
IRQE(1)  
0
4
DLY(1)  
1
3
CME  
0
2
1
CR1(1)  
0
Bit 0  
CR0(1)  
0
Read:  
Write:  
Reset:  
ADPU  
0
0
1. Can be written only once in first 64 cycles out of reset in normal mode or at any time in special modes  
= Unimplemented  
Figure 5-2. System Configuration Options Register (OPTION)  
ADPU — Analog-to-Digital Converter Power-Up Bit  
Refer to Chapter 3 Analog-to-Digital (A/D) Converter.  
CSEL — Clock Select Bit  
Refer to Chapter 3 Analog-to-Digital (A/D) Converter.  
IRQE — Configure IRQ for Edge-Sensitive-Only Operation Bit  
0 = IRQ is configured for level-sensitive operation.  
1 = IRQ is configured for edge-sensitive-only operation.  
DLY — Enable Oscillator Startup Delay Bit  
Refer to Chapter 2 Operating Modes and On-Chip Memory and Chapter 3 Analog-to-Digital (A/D)  
Converter.  
CME — Clock Monitor Enable Bit  
This control bit can be read or written at any time and controls whether or not the internal clock monitor  
circuit triggers a reset sequence when the system clock is slow or absent. When it is clear, the clock  
monitor circuit is disabled, and when it is set, the clock monitor circuit is enabled. Reset clears the CME  
bit.  
0 = Clock monitor circuit disabled  
1 = Slow or stopped clocks cause reset  
Bit 2 — Unimplemented  
Always reads 0  
CR[1:0] — COP Timer Rate Select Bit  
The internal E clock is first divided by 215 before it enters the COP watchdog system. These control  
bits determine a scaling factor for the watchdog timer. See Table 5-1 for specific timeout settings.  
M68HC11E Family Data Sheet, Rev. 5.1  
82  
Freescale Semiconductor  
Effects of Reset  
5.2.6 Configuration Control Register  
Address:  
$103F  
Bit 7  
6
EE2  
0
5
EE1  
0
4
EE0  
0
3
NOSEC  
1
2
NOCOP  
1
1
ROMON  
1
Bit 0  
EEON  
1
Read:  
Write:  
Reset:  
EE3  
0
Figure 5-3. Configuration Control Register (CONFIG)  
EE[3:0] — EEPROM Mapping Bits  
EE[3:0] apply only to MC68HC811E2. Refer to Chapter 2 Operating Modes and On-Chip Memory.  
NOSEC — Security Mode Disable Bit  
Refer to Chapter 2 Operating Modes and On-Chip Memory.  
NOCOP — COP System Disable Bit  
0 = COP enabled (forces reset on timeout)  
1 = COP disabled (does not force reset on timeout)  
ROMON — ROM (EPROM) Enable Bit  
Refer to Chapter 2 Operating Modes and On-Chip Memory.  
EEON — EEPROM Enable Bit  
Refer to Chapter 2 Operating Modes and On-Chip Memory.  
5.3 Effects of Reset  
When a reset condition is recognized, the internal registers and control bits are forced to an initial state.  
Depending on the cause of the reset and the operating mode, the reset vector can be fetched from any  
of six possible locations. Refer to Table 5-2.  
Table 5-2. Reset Cause, Reset Vector, and Operating Mode  
Normal Mode  
Vector  
Special Test  
or Bootstrap  
Cause of Reset  
POR or RESET pin  
Clock monitor failure  
COP Watchdog Timeout  
$FFFE, FFFF  
$FFFC, FFFD  
$FFFA, FFFB  
$BFFE, $BFFF  
$BFFC, $BFFD  
$BFFA, $BFFB  
These initial states then control on-chip peripheral systems to force them to known startup states, as  
described in the following subsections.  
5.3.1 Central Processor Unit (CPU)  
After reset, the central processor unit (CPU) fetches the restart vector from the appropriate address during  
the first three cycles and begins executing instructions. The stack pointer and other CPU registers are  
indeterminate immediately after reset; however, the X and I interrupt mask bits in the condition code  
register (CCR) are set to mask any interrupt requests. Also, the S bit in the CCR is set to inhibit stop mode.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
83  
Resets and Interrupts  
5.3.2 Memory Map  
After reset, the INIT register is initialized to $01, mapping the RAM at $00 and the control registers at  
$1000.  
For the MC68HC811E2, the CONFIG register resets to $FF. EEPROM mapping bits (EE[3:0]) place the  
EEPROM at $F800. Refer to the memory map diagram for MC68HC811E2 in Chapter 2 Operating Modes  
and On-Chip Memory.  
5.3.3 Timer  
During reset, the timer system is initialized to a count of $0000. The prescaler bits are cleared, and all  
output compare registers are initialized to $FFFF. All input capture registers are indeterminate after reset.  
The output compare 1 mask (OC1M) register is cleared so that successful OC1 compares do not affect  
any I/O pins. The other four output compares are configured so that they do not affect any I/O pins on  
successful compares. All input capture edge-detector circuits are configured for capture disabled  
operation. The timer overflow interrupt flag and all eight timer function interrupt flags are cleared. All nine  
timer interrupts are disabled because their mask bits have been cleared.  
The I4/O5 bit in the PACTL register is cleared to configure the I4/O5 function as OC5; however, the  
OM5:OL5 control bits in the TCTL1 register are clear so OC5 does not control the PA3 pin.  
5.3.4 Real-Time Interrupt (RTI)  
The real-time interrupt flag (RTIF) is cleared and automatic hardware interrupts are masked. The rate  
control bits are cleared after reset and can be initialized by software before the real-time interrupt (RTI)  
system is used.  
5.3.5 Pulse Accumulator  
The pulse accumulator system is disabled at reset so that the pulse accumulator input (PAI) pin defaults  
to being a general-purpose input pin.  
5.3.6 Computer Operating Properly (COP)  
The COP watchdog system is enabled if the NOCOP control bit in the CONFIG register is cleared and  
disabled if NOCOP is set. The COP rate is set for the shortest duration timeout.  
5.3.7 Serial Communications Interface (SCI)  
The reset condition of the SCI system is independent of the operating mode. At reset, the SCI baud rate  
control register (BAUD) is initialized to $04. All transmit and receive interrupts are masked and both the  
transmitter and receiver are disabled so the port pins default to being general-purpose I/O lines. The SCI  
frame format is initialized to an 8-bit character size. The send break and receiver wakeup functions are  
disabled. The TDRE and TC status bits in the SCI status register (SCSR) are both 1s, indicating that there  
is no transmit data in either the transmit data register or the transmit serial shift register. The RDRF, IDLE,  
OR, NF, FE, PF, and RAF receive-related status bits in the SCI control register 2 (SCCR2) are cleared.  
5.3.8 Serial Peripheral Interface (SPI)  
The SPI system is disabled by reset. The port pins associated with this function default to being  
general-purpose I/O lines.  
M68HC11E Family Data Sheet, Rev. 5.1  
84  
Freescale Semiconductor  
Reset and Interrupt Priority  
5.3.9 Analog-to-Digital (A/D) Converter  
The analog-to-digital (A/D) converter configuration is indeterminate after reset. The ADPU bit is cleared  
by reset, which disables the A/D system. The conversion complete flag is indeterminate.  
5.3.10 System  
The EEPROM programming controls are disabled, so the memory system is configured for normal read  
operation. PSEL[3:0] are initialized with the value %0110, causing the external IRQ pin to have the  
highest I-bit interrupt priority. The IRQ pin is configured for level-sensitive operation (for wired-OR  
systems). The RBOOT, SMOD, and MDA bits in the HPRIO register reflect the status of the MODB and  
MODA inputs at the rising edge of reset. MODA and MODB inputs select one of the four operating modes.  
After reset, writing SMOD and MDA in special modes causes the MCU to change operating modes. Refer  
to the description of HPRIO register in Chapter 2 Operating Modes and On-Chip Memory for a detailed  
description of SMOD and MDA. The DLY control bit is set to specify that an oscillator startup delay is  
imposed upon recovery from stop mode. The clock monitor system is disabled because CME is cleared.  
5.4 Reset and Interrupt Priority  
Resets and interrupts have a hardware priority that determines which reset or interrupt is serviced first  
when simultaneous requests occur. Any maskable interrupt can be given priority over other maskable  
interrupts.  
The first six interrupt sources are not maskable. The priority arrangement for these sources is:  
1. POR or RESET pin  
2. Clock monitor reset  
3. COP watchdog reset  
4. XIRQ interrupt  
5. Illegal opcode interrupt  
6. Software interrupt (SWI)  
The maskable interrupt sources have this priority arrangement:  
1. IRQ  
2. Real-time interrupt  
3. Timer input capture 1  
4. Timer input capture 2  
5. Timer input capture 3  
6. Timer output compare 1  
7. Timer output compare 2  
8. Timer output compare 3  
9. Timer output compare 4  
10. Timer input capture 4/output compare 5  
11. Timer overflow  
12. Pulse accumulator overflow  
13. Pulse accumulator input edge  
14. SPI transfer complete  
15. SCI system (refer to Figure 5-7)  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
85  
Resets and Interrupts  
Any one of these interrupts can be assigned the highest maskable interrupt priority by writing the  
appropriate value to the PSEL bits in the HPRIO register. Otherwise, the priority arrangement remains the  
same. An interrupt that is assigned highest priority is still subject to global masking by the I bit in the CCR,  
or by any associated local bits. Interrupt vectors are not affected by priority assignment. To avoid race  
conditions, HPRIO can be written only while I-bit interrupts are inhibited.  
5.4.1 Highest Priority Interrupt and Miscellaneous Register  
Address:  
$103C  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
RBOOT(1) SMOD(1)  
MDA(1)  
IRVNE  
PSEL2  
PSEL2  
PSEL1  
PSEL0  
Reset:  
Single chip:  
Expanded:  
Bootstrap:  
0
0
1
0
0
0
1
1
0
1
0
1
0
0
0
1
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
Special test:  
1. The values of the RBOOT, SMOD, and MDA reset bits depend on the mode selected at the  
RESET pin rising edge. Refer to Table 2-1. Hardware Mode Select Summary.  
Figure 5-4. Highest Priority I-Bit Interrupt  
and Miscellaneous Register (HPRIO)  
RBOOT — Read Bootstrap ROM Bit  
Has meaning only when the SMOD bit is a 1 (bootstrap mode or special test mode). At all other times  
this bit is clear and cannot be written. Refer to Chapter 2 Operating Modes and On-Chip Memory for  
more information.  
SMOD — Special Mode Select Bit  
This bit reflects the inverse of the MODB input pin at the rising edge of reset. Refer to Chapter 2  
Operating Modes and On-Chip Memory for more information.  
MDA — Mode Select A Bit  
The mode select A bit reflects the status of the MODA input pin at the rising edge of reset. Refer to  
Chapter 2 Operating Modes and On-Chip Memory for more information.  
IRVNE — Internal Read Visibility/Not E Bit  
The IRVNE control bit allows internal read accesses to be available on the external data bus during  
operation in expanded modes. In single-chip and bootstrap modes, IRVNE determines whether the E  
clock is driven out an external pin. For the MC68HC811E2, this bit is IRV and only controls internal  
read visibility. Refer to Chapter 2 Operating Modes and On-Chip Memory for more information.  
PSEL[3:0] — Priority Select Bits  
These bits select one interrupt source to be elevated above all other I-bit-related sources and can be  
written only while the I bit in the CCR is set (interrupts disabled).  
M68HC11E Family Data Sheet, Rev. 5.1  
86  
Freescale Semiconductor  
Interrupts  
Table 5-3. Highest Priority Interrupt Selection  
PSEL[3:0]  
0 0 0 0  
0 0 0 1  
0 0 1 0  
0 0 1 1  
0 1 0 0  
0 1 0 1  
0 1 1 0  
0 1 1 1  
1 0 0 0  
1 0 0 1  
1 0 1 0  
1 0 1 1  
1 1 0 0  
1 1 0 1  
1 1 1 0  
1 1 1 1  
Interrupt Source Promoted  
Timer overflow  
Pulse accumulator overflow  
Pulse accumulator input edge  
SPI serial transfer complete  
SCI serial system  
Reserved (default to IRQ)  
IRQ (external pin or parallel I/O)  
Real-time interrupt  
Timer input capture 1  
Timer input capture 2  
Timer input capture 3  
Timer output compare 1  
Timer output compare 2  
Timer output compare 3  
Timer output compare 4  
Timer input capture 4/output compare 5  
5.5 Interrupts  
The MCU has 18 interrupt vectors that support 22 interrupt sources. The 15 maskable interrupts are  
generated by on-chip peripheral systems. These interrupts are recognized when the global interrupt mask  
bit (I) in the condition code register (CCR) is clear. The three non-maskable interrupt sources are illegal  
opcode trap, software interrupt, and XIRQ pin. Refer to Table 5-4, which shows the interrupt sources and  
vector assignments for each source.  
For some interrupt sources, such as the SCI interrupts, the flags are automatically cleared during the  
normal course of responding to the interrupt requests. For example, the RDRF flag in the SCI system is  
cleared by the automatic clearing mechanism consisting of a read of the SCI status register while RDRF  
is set, followed by a read of the SCI data register. The normal response to an RDRF interrupt request  
would be to read the SCI status register to check for receive errors, then to read the received data from  
the SCI data register. These steps satisfy the automatic clearing mechanism without requiring special  
instructions.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
87  
Resets and Interrupts  
Table 5-4. Interrupt and Reset Vector Assignments  
CCR  
Mask Bit  
Local  
Mask  
Vector Address  
Interrupt Source  
FFC0, C1 – FFD4, D5 Reserved  
SCI serial system  
• SCI receive data register full  
• SCI receiver overrun  
• SCI transmit data register empty  
• SCI transmit complete  
RIE  
RIE  
TIE  
TCIE  
ILIE  
FFD6, D7  
I
• SCI idle line detect  
FFD8, D9  
FFDA, DB  
FFDC, DD  
FFDE, DF  
FFE0, E1  
FFE2, E3  
FFE4, E5  
FFE6, E7  
FFE8, E9  
FFEA, EB  
FFEC, ED  
FFEE, EF  
FFF0, F1  
FFF2, F3  
FFF4, F5  
FFF6, F7  
FFF8, F9  
FFFA, FB  
FFFC, FD  
FFFE, FF  
SPI serial transfer complete  
Pulse accumulator input edge  
Pulse accumulator overflow  
Timer overflow  
I
SPIE  
PAII  
I
I
PAOVI  
TOI  
I
Timer input capture 4/output compare 5  
Timer output compare 4  
Timer output compare 3  
Timer output compare 2  
Timer output compare 1  
Timer input capture 3  
Timer input capture 2  
Timer input capture 1  
Real-time interrupt  
I
I4/O5I  
OC4I  
OC3I  
OC2I  
OC1I  
IC3I  
I
I
I
I
I
I
IC2I  
I
IC1I  
I
RTII  
IRQ (external pin)  
I
None  
None  
None  
None  
NOCOP  
CME  
None  
XIRQ pin  
X
Software interrupt  
None  
None  
None  
None  
None  
Illegal opcode trap  
COP failure  
Clock monitor fail  
RESET  
5.5.1 Interrupt Recognition and Register Stacking  
An interrupt can be recognized at any time after it is enabled by its local mask, if any, and by the global  
mask bit in the CCR. Once an interrupt source is recognized, the CPU responds at the completion of the  
instruction being executed. Interrupt latency varies according to the number of cycles required to  
complete the current instruction. When the CPU begins to service an interrupt, the contents of the CPU  
registers are pushed onto the stack in the order shown in Table 5-5. After the CCR value is stacked, the  
I bit and the X bit, if XIRQ is pending, are set to inhibit further interrupts. The interrupt vector for the highest  
priority pending source is fetched and execution continues at the address specified by the vector. At the  
M68HC11E Family Data Sheet, Rev. 5.1  
88  
Freescale Semiconductor  
Interrupts  
end of the interrupt service routine, the return-from-interrupt instruction is executed and the saved  
registers are pulled from the stack in reverse order so that normal program execution can resume. Refer  
to Chapter 4 Central Processor Unit (CPU).  
Table 5-5. Stacking Order on Entry to Interrupts  
Memory Location  
SP  
CPU Registers  
PCL  
SP–1  
PCH  
SP–2  
IYL  
SP–3  
IYH  
SP–4  
IXL  
SP–5  
IXH  
SP–6  
ACCA  
ACCB  
CCR  
SP–7  
SP–8  
5.5.2 Non-Maskable Interrupt Request (XIRQ)  
Non-maskable interrupts are useful because they can always interrupt CPU operations. The most  
common use for such an interrupt is for serious system problems, such as program runaway or power  
failure. The XIRQ input is an updated version of the NMI (non-maskable interrupt) input of earlier MCUs.  
Upon reset, both the X bit and I bit of the CCR are set to inhibit all maskable interrupts and XIRQ. After  
minimum system initialization, software can clear the X bit by a TAP instruction, enabling XIRQ interrupts.  
Thereafter, software cannot set the X bit. Thus, an XIRQ interrupt is a non-maskable interrupt. Because  
the operation of the I-bit-related interrupt structure has no effect on the X bit, the internal XIRQ pin remains  
unmasked. In the interrupt priority logic, the XIRQ interrupt has a higher priority than any source that is  
maskable by the I bit. All I-bit-related interrupts operate normally with their own priority relationship.  
When an I-bit-related interrupt occurs, the I bit is automatically set by hardware after stacking the CCR  
byte. The X bit is not affected. When an X-bit-related interrupt occurs, both the X and I bits are  
automatically set by hardware after stacking the CCR. A return-from-interrupt instruction restores the X  
and I bits to their pre-interrupt request state.  
5.5.3 Illegal Opcode Trap  
Because not all possible opcodes or opcode sequences are defined, the MCU includes an illegal opcode  
detection circuit, which generates an interrupt request. When an illegal opcode is detected and the  
interrupt is recognized, the current value of the program counter is stacked. After interrupt service is  
complete, reinitialize the stack pointer so repeated execution of illegal opcodes does not cause stack  
underflow. Left uninitialized, the illegal opcode vector can point to a memory location that contains an  
illegal opcode. This condition causes an infinite loop that causes stack underflow. The stack grows until  
the system crashes.  
The illegal opcode trap mechanism works for all unimplemented opcodes on all four opcode map pages.  
The address stacked as the return address for the illegal opcode interrupt is the address of the first byte  
of the illegal opcode. Otherwise, it would be almost impossible to determine whether the illegal opcode  
had been one or two bytes. The stacked return address can be used as a pointer to the illegal opcode so  
the illegal opcode service routine can evaluate the offending opcode.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
89  
Resets and Interrupts  
5.5.4 Software Interrupt (SWI)  
SWI is an instruction, and thus cannot be interrupted until complete. SWI is not inhibited by the global  
mask bits in the CCR. Because execution of SWI sets the I mask bit, once an SWI interrupt begins, other  
interrupts are inhibited until SWI is complete, or until user software clears the I bit in the CCR.  
5.5.5 Maskable Interrupts  
The maskable interrupt structure of the MCU can be extended to include additional external interrupt  
sources through the IRQ pin. The default configuration of this pin is a low-level sensitive wired-OR  
network. When an event triggers an interrupt, a software accessible interrupt flag is set. When enabled,  
this flag causes a constant request for interrupt service. After the flag is cleared, the service request is  
released.  
5.5.6 Reset and Interrupt Processing  
Figure 5-5 and Figure 5-6 illustrate the reset and interrupt process. Figure 5-5 illustrates how the CPU  
begins from a reset and how interrupt detection relates to normal opcode fetches. Figure 5-6 is an  
expansion of a block in Figure 5-5 and illustrates interrupt priorities. Figure 5-7 shows the resolution of  
interrupt sources within the SCI subsystem.  
5.6 Low-Power Operation  
Both stop mode and wait mode suspend CPU operation until a reset or interrupt occurs. Wait mode  
suspends processing and reduces power consumption to an intermediate level. Stop mode turns off all  
on-chip clocks and reduces power consumption to an absolute minimum while retaining the contents of  
the entire RAM array.  
5.6.1 Wait Mode  
The WAI opcode places the MCU in wait mode, during which the CPU registers are stacked and CPU  
processing is suspended until a qualified interrupt is detected. The interrupt can be an external IRQ, an  
XIRQ, or any of the internally generated interrupts, such as the timer or serial interrupts. The on-chip  
crystal oscillator remains active throughout the wait standby period.  
The reduction of power in the wait condition depends on how many internal clock signals driving on-chip  
peripheral functions can be shut down. The CPU is always shut down during wait. While in the wait state,  
the address/data bus repeatedly runs read cycles to the address where the CCR contents were stacked.  
The MCU leaves the wait state when it senses any interrupt that has not been masked.  
The free-running timer system is shut down only if the I bit is set to 1 and the COP system is disabled by  
NOCOP being set to 1. Several other systems also can be in a reduced power-consumption state  
depending on the state of software-controlled configuration control bits. Power consumption by the  
analog-to-digital (A/D) converter is not affected significantly by the wait condition. However, the A/D  
converter current can be eliminated by writing the ADPU bit to 0. The SPI system is enabled or disabled  
by the SPE control bit. The SCI transmitter is enabled or disabled by the TE bit, and the SCI receiver is  
enabled or disabled by the RE bit. Therefore, the power consumption in wait is dependent on the  
particular application.  
M68HC11E Family Data Sheet, Rev. 5.1  
90  
Freescale Semiconductor  
Low-Power Operation  
HIGHEST  
PRIORITY  
POWER-ON RESET  
(POR)  
DELAY 4064 E CYCLES  
EXTERNAL RESET  
CLOCK MONITOR FAIL  
(WITH CME = 1)  
LOWEST  
PRIORITY  
COP WATCHDOG  
TIMEOUT  
(WITH NOCOP = 0)  
LOAD PROGRAM COUNTER  
WITH CONTENTS OF  
$FFFE, $FFFF  
LOAD PROGRAM COUNTER  
WITH CONTENTS OF  
$FFFC, $FFFD  
LOAD PROGRAM COUNTER  
WITH CONTENTS OF  
$FFFA, $FFFB  
(VECTOR FETCH)  
(VECTOR FETCH)  
(VECTOR FETCH)  
SET BITS S, I, AND X  
RESET MCU  
HARDWARE  
BEGIN INSTRUCTION  
SEQUENCE  
1A  
BIT X IN  
CCR = 1?  
Y
N
XIRQ  
PIN LOW?  
Y
STACK CPU  
REGISTERS  
N
SET BITS I AND X  
FETCH VECTOR  
$FFF4, $FFF5  
2A  
Figure 5-5. Processing Flow Out of Reset (Sheet 1 of 2)  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
91  
Resets and Interrupts  
2A  
Y
BIT I IN  
CCR = 1?  
N
ANY I-BIT  
INTERRUPT  
PENDING?  
Y
STACK CPU  
REGISTERS  
N
FETCH OPCODE  
Y
ILLEGAL  
OPCODE?  
STACK CPU  
REGISTERS  
N
SET BIT I IN CCR  
WAI  
INSTRUCTION?  
FETCH VECTOR  
$FFF8, $FFF9  
Y
STACK CPU  
REGISTERS  
N
SWI  
INSTRUCTION?  
Y
Y
ANY  
INTERRUPT  
PENDING?  
STACK CPU  
REGISTERS  
N
N
SET BIT I IN CCR  
Y
FETCH VECTOR  
$FFF6, $FFF7  
SET BIT I IN CCR  
RTI  
INSTRUCTION?  
RESOLVE INTERRUPT  
PRIORITY AND FETCH  
VECTOR FOR HIGHEST  
PENDING SOURCE  
SEE FIGURE 5–2  
N
RESTORE CPU  
REGISTERS  
FROM STACK  
EXECUTE THIS  
INSTRUCTION  
1A  
Figure 5-5. Processing Flow Out of Reset (Sheet 2 of 2)  
M68HC11E Family Data Sheet, Rev. 5.1  
92  
Freescale Semiconductor  
Low-Power Operation  
BEGIN  
X BIT  
IN CCR  
SET ?  
YES  
YES  
YES  
YES  
XIRQ PIN  
LOW ?  
SET X BIT IN CCR  
FETCH VECTOR  
$FFF4, FFF5  
NO  
NO  
HIGHEST  
PRIORITY  
INTERRUPT  
?
FETCH VECTOR  
NO  
FETCH VECTOR  
$FFF2, FFF3  
IRQ ?  
NO  
YES  
YES  
YES  
YES  
YES  
YES  
YES  
YES  
REAL-TIME  
INTERRUPT  
?
FETCH VECTOR  
$FFF0, FFF1  
RTII = 1 ?  
NO  
NO  
FETCH VECTOR  
$FFEE, FFEF  
TIMER  
IC1F ?  
IC1I = 1 ?  
NO  
NO  
FETCH VECTOR  
$FFEC, FFED  
TIMER  
IC2F ?  
IC2I = 1 ?  
NO  
NO  
YES  
YES  
FETCH VECTOR  
$FFEA, FFEB  
TIMER  
IC3F ?  
IC3I = 1 ?  
NO  
NO  
FETCH VECTOR  
$FFE8, FFE9  
TIMER  
OC1F ?  
OC1I = 1 ?  
NO  
NO  
2A  
2B  
Figure 5-6. Interrupt Priority Resolution (Sheet 1 of 2)  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
93  
Resets and Interrupts  
2A  
2B  
Y
Y
FLAG  
OC2F = 1?  
FETCH VECTOR  
$FFE6, $FFE7  
OC2I = 1?  
N
N
Y
Y
Y
Y
FLAG  
OC3F = 1  
FETCH VECTOR  
$FFE4, $FFE5  
OC3I = 1?  
N
N
FLAG  
OC4F = 1?  
FETCH VECTOR  
$FFE2, $FFE3  
OC4I = 1?  
N
N
Y
Y
Y
Y
FLAG  
I4/O5IF = 1?  
FETCH VECTOR  
$FFE0, $FFE1  
I4/O5I = 1?  
N
N
FLAG  
TOF = 1?  
FETCH VECTOR  
$FFDE, $FFDF  
TOI = 1?  
N
N
Y
Y
Y
Y
FLAG  
PAOVF = 1  
FETCH VECTOR  
$FFDC, $FFDD  
PAOVI = 1?  
N
N
FLAG  
PAIF = 1?  
FETCH VECTOR  
$FFDA, $FFDB  
PAII = 1?  
N
N
FLAGS  
SPIF = 1? OR  
MODF = 1?  
Y
Y
Y
FETCH VECTOR  
$FFD8, $FFD9  
SPIE = 1?  
N
N
SCI  
FETCH VECTOR  
$FFD6, $FFD7  
INTERRUPT?  
SEE FIGURE  
5–3  
FETCH VECTOR  
$FFF2, $FFF3  
N
END  
Figure 5-6. Interrupt Priority Resolution (Sheet 2 of 2)  
M68HC11E Family Data Sheet, Rev. 5.1  
94  
Freescale Semiconductor  
Low-Power Operation  
BEGIN  
Y
Y
FLAG  
RDRF = 1?  
N
Y
Y
Y
Y
Y
OR = 1?  
N
RIE = 1?  
N
RE = 1?  
N
Y
Y
Y
Y
TDRE = 1?  
N
TE = 1?  
N
TIE = 1?  
N
TC = 1?  
N
TCIE = 1?  
N
Y
IDLE = 1?  
RE = 1?  
N
ILIE = 1?  
N
N
NO  
VALID SCI REQUEST  
VALID SCI REQUEST  
Figure 5-7. Interrupt Source Resolution Within SCI  
5.6.2 Stop Mode  
Executing the STOP instruction while the S bit in the CCR is equal to 0 places the MCU in stop mode. If  
the S bit is not 0, the stop opcode is treated as a no-op (NOP). Stop mode offers minimum power  
consumption because all clocks, including the crystal oscillator, are stopped while in this mode. To exit  
stop and resume normal processing, a logic low level must be applied to one of the external interrupts  
(IRQ or XIRQ) or to the RESET pin. A pending edge-triggered IRQ can also bring the CPU out of stop.  
Because all clocks are stopped in this mode, all internal peripheral functions also stop. The data in the  
internal RAM is retained as long as VDD power is maintained. The CPU state and I/O pin levels are static  
and are unchanged by stop. Therefore, when an interrupt comes to restart the system, the MCU resumes  
processing as if there were no interruption. If reset is used to restart the system, a normal reset sequence  
results in which all I/O pins and functions are also restored to their initial states.  
To use the IRQ pin as a means of recovering from stop, the I bit in the CCR must be clear (IRQ not  
masked). The XIRQ pin can be used to wake up the MCU from stop regardless of the state of the X bit in  
the CCR, although the recovery sequence depends on the state of the X bit. If X is set to 0 (XIRQ not  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
95  
Resets and Interrupts  
masked), the MCU starts up, beginning with the stacking sequence leading to normal service of the XIRQ  
request. If X is set to 1 (XIRQ masked or inhibited), then processing continues with the instruction that  
immediately follows the STOP instruction, and no XIRQ interrupt service is requested or pending.  
Because the oscillator is stopped in stop mode, a restart delay may be imposed to allow oscillator  
stabilization upon leaving stop. If the internal oscillator is being used, this delay is required; however, if a  
stable external oscillator is being used, the DLY control bit can be used to bypass this startup delay. The  
DLY control bit is set by reset and can be optionally cleared during initialization. If the DLY equal to 0  
option is used to avoid startup delay on recovery from stop, then reset should not be used as the means  
of recovering from stop, as this causes DLY to be set again by reset, imposing the restart delay. This same  
delay also applies to power-on reset, regardless of the state of the DLY control bit, but does not apply to  
a reset while the clocks are running.  
M68HC11E Family Data Sheet, Rev. 5.1  
96  
Freescale Semiconductor  
Chapter 6  
Parallel Input/Output (I/O) Ports  
6.1 Introduction  
All M68HC11 E-series MCUs have five input/output (I/O) ports and up to 38 I/O lines, depending on the  
operating mode. Refer to Table 6-1 for a summary of the ports and their shared functions.  
Table 6-1. Input/Output Ports  
Input  
Pins  
Output  
Pins  
Bidirectional  
Pins  
Port  
Shared Functions  
Port A  
Port B  
Port C  
3
3
8
2
8
Timer  
High-order address  
Low-order address and data bus  
Serial communications interface (SCI)  
and serial peripheral interface (SPI)  
Port D  
Port E  
8
6
Analog-to-digital (A/D) converter  
Port pin function is mode dependent. Do not confuse pin function with the electrical state of the pin at  
reset. Port pins are either driven to a specified logic level or are configured as high-impedance inputs. I/O  
pins configured as high-impedance inputs have port data that is indeterminate.  
In port descriptions, an I indicates this condition. Port pins that are driven to a known logic level during  
reset are shown with a value of either 1 or 0. Some control bits are unaffected by reset. Reset states for  
these bits are indicated with a U.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
97  
Parallel Input/Output (I/O) Ports  
6.2 Port A  
Port A shares functions with the timer system and has:  
Three input-only pins  
Three output-only pins  
Two bidirectional I/O pins  
Address:  
$1000  
Bit 7  
6
5
4
3
2
1
Bit 0  
PA0  
Read:  
Write:  
PA7  
PA6  
PA5  
PA4  
PA3  
PA2  
PA1  
Reset:  
I
0
0
0
I
I
I
I
Alternate function:  
And/or:  
PAI  
OC1  
OC2  
OC1  
OC3  
OC1  
OC4  
OC1  
IC4/OC5  
OC1  
IC1  
IC2  
IC3  
I = Indeterminate after reset  
Figure 6-1. Port A Data Register (PORTA)  
Address:  
$1026  
Bit 7  
DDRA7  
0
6
PAEWN  
0
5
PAMOD  
0
4
PEDGE  
0
3
DDRA3  
0
2
I4/O5  
0
1
RTR1  
0
Bit 0  
RTR0  
0
Read:  
Write:  
Reset:  
Figure 6-2. Pulse Accumulator Control Register (PACTL)  
DDRA7 — Data Direction for Port A Bit 7  
Overridden if an output compare function is configured to control the PA7 pin  
0 = Input  
1 = Output  
The pulse accumulator uses port A bit 7 as the PAI input, but the pin can also be used as  
general-purpose I/O or as an output compare.  
NOTE  
Even when port A bit 7 is configured as an output, the pin still drives the  
input to the pulse accumulator.  
PAEN — Pulse Accumulator System Enable Bit  
Refer to Chapter 9 Timing Systems.  
PAMOD — Pulse Accumulator Mode Bit  
Refer to Chapter 9 Timing Systems.  
PEDGE — Pulse Accumulator Edge Control Bit  
Refer to Chapter 9 Timing Systems.  
DDRA3 — Data Direction for Port A Bit 3  
This bit is overridden if an output compare function is configured to control the PA3 pin.  
0 = Input  
1 = Output  
I4/O5 — Input Capture 4/Output Compare 5 Bit  
Refer to Chapter 9 Timing Systems.  
RTR[1:0] — RTI Interrupt Rate Select Bits  
Refer to Chapter 9 Timing Systems.  
M68HC11E Family Data Sheet, Rev. 5.1  
98  
Freescale Semiconductor  
Port B  
6.3 Port B  
In single-chip or bootstrap modes, port B pins are general-purpose outputs. In expanded or special test  
modes, port B pins are high-order address outputs.  
Address:  
$1004  
Bit 7  
6
5
4
3
2
1
Bit 0  
Single-chip or bootstrap modes:  
Read:  
PB7  
0
PB6  
PB5  
0
PB4  
0
PB3  
0
PB2  
0
PB1  
0
PB0  
0
Write:  
Reset:  
0
Expanded or special test modes:  
Read:  
ADDR15  
0
ADDR14  
ADDR13  
0
ADDR12  
0
ADDR11  
0
ADDR10  
0
ADDR9  
0
ADDR8  
0
Write:  
Reset:  
0
Figure 6-3. Port B Data Register (PORTB)  
6.4 Port C  
In single-chip and bootstrap modes, port C pins reset to high-impedance inputs. (DDRC bits are set to 0.)  
In expanded and special test modes, port C pins are multiplexed address/data bus and the port C register  
address is treated as an external memory location.  
Address:  
$1003  
Bit 7  
6
5
4
3
2
1
Bit 0  
PC0  
Single-chip or bootstrap modes:  
Read:  
PC7  
PC6  
PC5  
PC4  
PC3  
PC2  
PC1  
Write:  
Reset:  
Indeterminate after reset  
Expanded or special test modes:  
Read:  
Write:  
Reset:  
ADDR7  
DATA7  
ADDR6  
DATA6  
ADDR5  
DATA5  
ADDR4  
DATA4  
ADDR3  
DATA3  
ADDR2  
DATA2  
ADDR1  
DATA1  
ADDR0  
DATA0  
Indeterminate after reset  
Figure 6-4. Port C Data Register (PORTC)  
Address:  
$1005  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
Reset:  
PCL7  
PCL6  
PCL5  
PCL4  
PCL3  
PCL2  
PCL1  
PCL0  
Indeterminate after reset  
Figure 6-5. Port C Latched Register (PORTCL)  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
99  
Parallel Input/Output (I/O) Ports  
PORTCL is used in the handshake clearing mechanism. When an active edge occurs on the STRA pin,  
port C data is latched into the PORTCL register. Reads of this register return the last value latched into  
PORTCL and clear STAF flag (following a read of PIOC with STAF set).  
Address:  
$1007  
Bit 7  
6
DDRC6  
0
5
DDRC5  
0
4
DDRC4  
0
3
DDRC3  
0
2
DDRC2  
0
1
DDRC1  
0
Bit 0  
DDRC0  
0
Read:  
Write:  
Reset:  
DDRC7  
0
Figure 6-6. Port C Data Direction Register (DDRC)  
DDRC[7:0] — Port C Data Direction Bits  
In the 3-state variation of output handshake mode, clear the corresponding DDRC bits. Refer to Figure  
10-13. 3-State Variation of Output Handshake Timing Diagram (STRA Enables Output Buffer).  
0 = Input  
1 = Output  
6.5 Port D  
In all modes, port D bits [5:0] can be used either for general-purpose I/O or with the serial communications  
interface (SCI) and serial peripheral interface (SPI) subsystems. During reset, port D pins PD[5:0] are  
configured as high-impedance inputs (DDRD bits cleared).  
Address:  
$1008  
Bit 7  
6
0
5
PD5  
I
4
PD4  
I
3
PD3  
I
2
PD2  
I
1
PD1  
I
Bit 0  
PD0  
I
Read:  
Write:  
Reset:  
0
PD5  
SS  
PD4  
SCK  
PD3  
MOSI  
PD2  
MISO  
PD1  
Tx  
PD0  
RxD  
Alternate Function:  
I = Indeterminate after reset  
Figure 6-7. Port D Data Register (PORTD)  
Address:  
$1009  
Bit 7  
6
5
DDRD5  
0
4
DDRD4  
0
3
DDRD3  
0
2
DDRD2  
0
1
Bit 0  
Read:  
Write:  
Reset:  
DDRD1  
0
DDRD0  
0
0
0
= Unimplemented  
Figure 6-8. Port D Data Direction Register (DDRD)  
Bits [7:6] — Unimplemented  
Always read 0  
DDRD[5:0] — Port D Data Direction Bits  
When DDRD bit 5 is 1 and MSTR = 1 in SPCR, PD5/SS is a general-purpose output and mode fault  
logic is disabled.  
0 = Input  
1 = Output  
M68HC11E Family Data Sheet, Rev. 5.1  
100  
Freescale Semiconductor  
Port E  
6.6 Port E  
Port E is used for general-purpose static inputs or pins that share functions with the analog-to-digital (A/D)  
converter system. When some port E pins are being used for general-purpose input and others are being  
used as A/D inputs, PORTE should not be read during the sample portion of an A/D conversion.  
Address:  
$100A  
Bit 7  
6
5
4
3
2
1
Bit 0  
PE0  
Read:  
Write:  
PE7  
PE6  
PE5  
PE4  
PE3  
PE2  
PE1  
Reset:  
Indeterminate after reset  
AN4 AN3  
Alternate Function:  
AN7  
AN6  
AN5  
AN2  
AN1  
AN0  
Figure 6-9. Port E Data Register (PORTE)  
6.7 Handshake Protocol  
Simple and full handshake input and output functions are available on ports B and C pins in single-chip  
mode. In simple strobed mode, port B is a strobed output port and port C is a latching input port. The two  
activities are available simultaneously.  
The STRB output is pulsed for two E-clock periods each time there is a write to the PORTB register. The  
INVB bit in the PIOC register controls the polarity of STRB pulses. Port C levels are latched into the  
alternate port C latch (PORTCL) register on each assertion of the STRA input. STRA edge select, flag,  
and interrupt enable bits are located in the PIOC register. Any or all of the port C lines can still be used  
as general-purpose I/O while in strobed input mode.  
Full handshake modes use port C pins and the STRA and STRB lines. Input and output handshake  
modes are supported, and output handshake mode has a 3-stated variation. STRA is an edge-detecting  
input and STRB is a handshake output. Control and enable bits are located in the PIOC register.  
In full input handshake mode, the MCU asserts STRB to signal an external system that it is ready to latch  
data. Port C logic levels are latched into PORTCL when the STRA line is asserted by the external system.  
The MCU then negates STRB. The MCU reasserts STRB after the PORTCL register is read. In this mode,  
a mix of latched inputs, static inputs, and static outputs is allowed on port C, differentiated by the data  
direction bits and use of the PORTC and PORTCL registers.  
In full output handshake mode, the MCU writes data to PORTCL which, in turn, asserts the STRB output  
to indicate that data is ready. The external system reads port C data and asserts the STRA input to  
acknowledge that data has been received.  
In the 3-state variation of output handshake mode, lines intended as 3-state handshake outputs are  
configured as inputs by clearing the corresponding DDRC bits. The MCU writes data to PORTCL and  
asserts STRB. The external system responds by activating the STRA input, which forces the MCU to drive  
the data in PORTC out on all of the port C lines. After the trailing edge of the active signal on STRA, the  
MCU negates the STRB signal. The 3-state mode variation does not allow part of port C to be used for  
static inputs while other port C pins are being used for handshake outputs. Refer to the 6.8 Parallel I/O  
Control Register for further information.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
101  
Parallel Input/Output (I/O) Ports  
6.8 Parallel I/O Control Register  
The parallel handshake functions are available only in the single-chip operating mode. PIOC is a  
read/write register except for bit 7, which is read only. Table 6-2 shows a summary of handshake  
operations.  
Table 6-2. Parallel I/O Control  
STAF  
Clearing  
HNDS OIN  
PLS  
EGA  
Port B  
Port C  
Sequence  
Read  
Inputs latched into  
PORTCL on any  
active edge on  
STRA  
Simple  
strobed  
mode  
PIOC with  
STAF = 1  
then read  
PORTCL  
STRB pulses  
on writes  
to PORTB  
0
1
0
1
X
0
X
Read  
Full-input  
hand-  
shake  
0 = STRB  
active level  
1 = STRB  
active pulse  
Inputs latched into Normal output  
PIOC with  
STAF = 1  
then read  
PORTCL  
1
0
PORTCL on any  
active edge on  
STRA  
port, unaffected  
in handshake  
modes  
mode  
Driven as outputs if  
STRA at active  
level; follows  
DDRC  
if STRA not at  
active level  
Full-  
Read  
0 = STRB  
active level  
1 = STRB  
active pulse  
0
Normal output  
port, unaffected  
in handshake  
modes  
output  
hand-  
shake  
mode  
PIOC with  
STAF = 1  
then write  
PORTCL  
Port C  
Driven  
1
1
1
STRA  
Active Edge  
Follow  
DDRC  
Follow  
DDRC  
Address:  
$1002  
Bit 7  
6
5
CWOM  
0
4
HNDS  
0
3
OIN  
0
2
1
EGA  
1
Bit 0  
Read:  
Write:  
Reset:  
STAF  
0
STAI  
0
PLS  
U
INVB  
1
U = Unaffected  
Figure 6-10. Parallel I/O Control Register (PIOC)  
STAF — Strobe A Interrupt Status Flag  
STAF is set when the selected edge occurs on strobe A. This bit can be cleared by a read of PIOC with  
STAF set followed by a read of PORTCL (simple strobed or full input handshake mode) or a write to  
PORTCL (output handshake mode).  
0 = No edge on strobe A  
1 = Selected edge on strobe A  
STAI — Strobe A Interrupt Enable Mask Bit  
0 = STAF does not request interrupt  
1 = STAF requests interrupt  
M68HC11E Family Data Sheet, Rev. 5.1  
102  
Freescale Semiconductor  
Parallel I/O Control Register  
CWOM — Port C Wired-OR Mode Bit (affects all eight port C pins)  
It is customary to have an external pullup resistor on lines that are driven by open-drain devices.  
0 = Port C outputs are normal CMOS outputs.  
1 = Port C outputs are open-drain outputs.  
HNDS — Handshake Mode Bit  
0 = Simple strobe mode  
1 = Full input or output handshake mode  
OIN — Output or Input Handshake Select Bit  
HNDS must be set to 1 for this bit to have meaning.  
0 = Input handshake  
1 = Output handshake  
PLS — Pulsed/Interlocked Handshake Operation Bit  
HNDS must be set to 1 for this bit to have meaning. When interlocked handshake is selected, strobe  
B is active until the selected edge of strobe A is detected.  
0 = Interlocked handshake  
1 = Pulsed handshake (Strobe B pulses high for two E-clock cycles.)  
EGA — Active Edge for Strobe A Bit  
0 = STRA falling edge selected, high level activates port C outputs (output handshake)  
1 = STRA rising edge selected, low level activates port C outputs (output handshake)  
INVB — Invert Strobe B Bit  
0 = Active level is logic 0.  
1 = Active level is logic 1.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
103  
Parallel Input/Output (I/O) Ports  
M68HC11E Family Data Sheet, Rev. 5.1  
104  
Freescale Semiconductor  
Chapter 7  
Serial Communications Interface (SCI)  
7.1 Introduction  
The serial communications interface (SCI) is a universal asynchronous receiver transmitter (UART), one  
of two independent serial input/output (I/O) subsystems in the M68HC11 E series of microcontrollers. It  
has a standard non-return-to-zero (NRZ) format (one start bit , eight or nine data bits, and one stop bit).  
Several baud rates are available. The SCI transmitter and receiver are independent, but use the same  
data format and bit rate.  
All members of the E series contain the same SCI, with one exception. The SCI system in the  
MC68HC11E20 and MC68HC711E20 MCUs have an enhanced SCI baud rate generator. A divide-by-39  
stage has been added that is enabled by an extra bit in the BAUD register. This increases the available  
SCI baud rate selections. Refer to Figure 7-8 and 7.7.5 Baud Rate Register.  
7.2 Data Format  
The serial data format requires these conditions:  
1. An idle line in the high state before transmission or reception of a message  
2. A start bit, logic 0, transmitted or received, that indicates the start of each character  
3. Data that is transmitted and received least significant bit (LSB) first  
4. A stop bit, logic 1, used to indicate the end of a frame. A frame consists of a start bit, a character  
of eight or nine data bits, and a stop bit.  
5. A break, defined as the transmission or reception of a logic 0 for some multiple number of frames  
Selection of the word length is controlled by the M bit of SCI control register (SCCR1).  
7.3 Transmit Operation  
The SCI transmitter includes a parallel transmit data register (SCDR) and a serial shift register. The  
contents of the serial shift register can be written only through the SCDR. This double buffered operation  
allows a character to be shifted out serially while another character is waiting in the SCDR to be  
transferred into the  
serial shift register. The output of the serial shift register is applied to TxD as long as transmission is in  
progress or the transmit enable (TE) bit of serial communication control register 2 (SCCR2) is set. The  
block diagram, Figure 7-1, shows the transmit serial shift register and the buffer logic at the top of the  
figure.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
105  
Serial Communications Interface (SCI)  
WRITE ONLY  
TRANSMITTER  
BAUD RATE  
CLOCK  
SCDR Tx BUFFER  
DDD1  
10 (11) - BIT Tx SHIFT REGISTER  
(8) 7 L  
SEE NOTE  
PD1  
TxD  
PIN BUFFER  
AND CONTROL  
H
6
5
4
3
2
1
0
8
FORCE PIN  
DIRECTION (OUT)  
TRANSMITTER  
CONTROL LOGIC  
8
SCSR  
INTERRUPT STATUS  
SCCR1 SCI CONTROL 1  
8
TDRE  
TIE  
TC  
TCIE  
SCCR2 SCI CONTROL 2  
SCI Rx  
REQUESTS  
SCI INTERRUPT  
REQUEST  
INTERNAL  
DATA BUS  
Note: Refer to Figure B-1. EVBU Schematic Diagram for an example of connecting TxD to a PC.  
Figure 7-1. SCI Transmitter Block Diagram  
M68HC11E Family Data Sheet, Rev. 5.1  
106  
Freescale Semiconductor  
Receive Operation  
7.4 Receive Operation  
During receive operations, the transmit sequence is reversed. The serial shift register receives data and  
transfers it to a parallel receive data register (SCDR) as a complete word. This double buffered operation  
allows a character to be shifted in serially while another character is already in the SCDR. An advanced  
data recovery scheme distinguishes valid data from noise in the serial data stream. The data input is  
selectively sampled to detect receive data, and a majority voting circuit determines the value and integrity  
of each bit. See Figure 7-2.  
7.5 Wakeup Feature  
The wakeup feature reduces SCI service overhead in multiple receiver systems. Software for each  
receiver evaluates the first character of each message. The receiver is placed in wakeup mode by writing  
a 1 to the RWU bit in the SCCR2 register. While RWU is 1, all of the receiver-related status flags (RDRF,  
IDLE, OR, NF, and FE) are inhibited (cannot become set). Although RWU can be cleared by a software  
write to SCCR2, to do so would be unusual. Normally, RWU is set by software and is cleared  
automatically with hardware. Whenever a new message begins, logic alerts the sleeping receivers to  
wake up and evaluate the initial character of the new message.  
Two methods of wakeup are available:  
Idle-line wakeup  
Address-mark wakeup  
During idle-line wakeup, a sleeping receiver awakens as soon as the RxD line becomes idle. In the  
address-mark wakeup, logic 1 in the most significant bit (MSB) of a character wakes up all sleeping  
receivers.  
7.5.1 Idle-Line Wakeup  
To use the receiver wakeup method, establish a software addressing scheme to allow the transmitting  
devices to direct a message to individual receivers or to groups of receivers. This addressing scheme can  
take any form as long as all transmitting and receiving devices are programmed to understand the same  
scheme. Because the addressing information is usually the first frame(s) in a message, receivers that are  
not part of the current task do not become burdened with the entire set of addressing frames. All receivers  
are awake (RWU = 0) when each message begins. As soon as a receiver determines that the message  
is not intended for it, software sets the RWU bit (RWU = 1), which inhibits further flag setting until the RxD  
line goes idle at the end of the message. As soon as an idle line is detected by receiver logic, hardware  
automatically clears the RWU bit so that the first frame of the next message can be received. This type  
of receiver wakeup requires a minimum of one idle-line frame time between messages and no idle time  
between frames in a message.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
107  
Serial Communications Interface (SCI)  
RECEIVER  
BAUD RATE  
CLOCK  
DDD0  
÷16  
10 (11) - BIT  
Rx SHIFT REGISTER  
SEE NOTE  
PIN BUFFER  
AND CONTROL  
DATA  
RECOVERY  
PD0  
RxD  
(8)  
7
6
5
4
3
2
1
0
MSB  
ALL 1s  
DISABLE  
DRIVER  
RE  
M
WAKEUP  
LOGIC  
RWU  
8
SCCR1 SCI CONTROL 1  
SCSR SCI STATUS 1  
SCDR Rx BUFFER  
READ ONLY  
8
RDRF  
RIE  
IDLE  
ILIE  
OR  
RIE  
8
SCCR2 SCI CONTROL 2  
SCI Tx  
REQUESTS  
SCI INTERRUPT  
REQUEST  
INTERNAL  
DATA BUS  
Note: Refer to Figure B-1. EVBU Schematic Diagram for an example of connecting RxD to a PC.  
Figure 7-2. SCI Receiver Block Diagram  
M68HC11E Family Data Sheet, Rev. 5.1  
108  
Freescale Semiconductor  
SCI Error Detection  
7.5.2 Address-Mark Wakeup  
The serial characters in this type of wakeup consist of seven (eight if M = 1) information bits and an MSB,  
which indicates an address character (when set to 1, or mark). The first character of each message is an  
addressing character (MSB = 1). All receivers in the system evaluate this character to determine if the  
remainder of the message is directed toward this particular receiver. As soon as a receiver determines  
that a message is not intended for it, the receiver activates the RWU function by using a software write to  
set the RWU bit. Because setting RWU inhibits receiver-related flags, there is no further software  
overhead for the rest of this message.  
When the next message begins, its first character has its MSB set, which automatically clears the RWU  
bit and enables normal character reception. The first character whose MSB is set is also the first character  
to be received after wakeup because RWU gets cleared before the stop bit for that frame is serially  
received. This type of wakeup allows messages to include gaps of idle time, unlike the idle-line method,  
but there is a loss of efficiency because of the extra bit time for each character (address bit) required for  
all characters.  
7.6 SCI Error Detection  
Three error conditions – SCDR overrun, received bit noise, and framing – can occur during generation of  
SCI system interrupts. Three bits (OR, NF, and FE) in the serial communications status register (SCSR)  
indicate if one of these error conditions exists.  
The overrun error (OR) bit is set when the next byte is ready to be transferred from the receive shift  
register to the SCDR and the SCDR is already full (RDRF bit is set). When an overrun error occurs, the  
data that caused the overrun is lost and the data that was already in SCDR is not disturbed. The OR is  
cleared when the SCSR is read (with OR set), followed by a read of the SCDR.  
The noise flag (NF) bit is set if there is noise on any of the received bits, including the start and stop bits.  
The NF bit is not set until the RDRF flag is set. The NF bit is cleared when the SCSR is read (with FE  
equal to 1) followed by a read of the SCDR.  
When no stop bit is detected in the received data character, the framing error (FE) bit is set. FE is set at  
the same time as the RDRF. If the byte received causes both framing and overrun errors, the processor  
only recognizes the overrun error. The framing error flag inhibits further transfer of data into the SCDR  
until it is cleared. The FE bit is cleared when the SCSR is read (with FE equal to 1) followed by a read of  
the SCDR.  
7.7 SCI Registers  
Five addressable registers are associated with the SCI:  
Four control and status registers:  
Serial communications control register 1 (SCCR1)  
Serial communications control register 2 (SCCR2)  
Baud rate register (BAUD)  
Serial communications status register (SCSR)  
One data register:  
Serial communications data register (SCDR)  
The SCI registers are the same for all M68HC11 E-series devices with one exception. The SCI system  
for MC68HC(7)11E20 contains an extra bit in the BAUD register that provides a greater selection of baud  
prescaler rates. Refer to 7.7.5 Baud Rate Register, Figure 7-8, and Figure 7-9.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
109  
Serial Communications Interface (SCI)  
7.7.1 Serial Communications Data Register  
SCDR is a parallel register that performs two functions:  
The receive data register when it is read  
The transmit data register when it is written  
Reads access the receive data buffer and writes access the transmit data buffer. Receive and transmit  
are double buffered.  
Address:  
$102F  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
Reset:  
R7/T7  
R6/T6  
R5/T5  
R4/T4  
R3/T3  
R2/T2  
R1/T1  
R0/T0  
Indeterminate after reset  
Figure 7-3. Serial Communications Data Register (SCDR)  
7.7.2 Serial Communications Control Register 1  
The SCCR1 register provides the control bits that determine word length and select the method used for  
the wakeup feature.  
Address:  
$102C  
Bit 7  
6
T8  
I
5
0
4
M
0
3
WAKE  
0
2
0
1
0
Bit 0  
Read:  
Write:  
Reset:  
R8  
I
0
I = Indeterminate after reset  
= Unimplemented  
Figure 7-4. Serial Communications Control Register 1 (SCCR1)  
R8 — Receive Data Bit 8  
If M bit is set, R8 stores the ninth bit in the receive data character.  
T8 — Transmit Data Bit 8  
If M bit is set, T8 stores the ninth bit in the transmit data character.  
Bit 5 — Unimplemented  
Always reads 0  
M — Mode Bit (select character format)  
0 = Start bit, 8 data bits, 1 stop bit  
1 = Start bit, 9 data bits, 1 stop bit  
WAKE — Wakeup by Address Mark/Idle Bit  
0 = Wakeup by IDLE line recognition  
1 = Wakeup by address mark (most significant data bit set)  
Bits [2:0] — Unimplemented  
Always read 0  
M68HC11E Family Data Sheet, Rev. 5.1  
110  
Freescale Semiconductor  
SCI Registers  
7.7.3 Serial Communications Control Register 2  
The SCCR2 register provides the control bits that enable or disable individual SCI functions.  
Address:  
$102D  
Bit 7  
6
TCIE  
0
5
RIE  
0
4
ILIE  
0
3
TE  
0
2
RE  
0
1
RWU  
0
Bit 0  
SBK  
0
Read:  
Write:  
Reset:  
TIE  
0
Figure 7-5. Serial Communications Control Register 2 (SCCR2)  
TIE — Transmit Interrupt Enable Bit  
0 = TDRE interrupts disabled  
1 = SCI interrupt requested when TDRE status flag is set  
TCIE — Transmit Complete Interrupt Enable Bit  
0 = TC interrupts disabled  
1 = SCI interrupt requested when TC status flag is set  
RIE — Receiver Interrupt Enable Bit  
0 = RDRF and OR interrupts disabled  
1 = SCI interrupt requested when RDRF flag or the OR status flag is set  
ILIE — Idle-Line Interrupt Enable Bit  
0 = IDLE interrupts disabled  
1 = SCI interrupt requested when IDLE status flag is set  
TE — Transmitter Enable Bit  
When TE goes from 0 to 1, one unit of idle character time (logic 1) is queued as a preamble.  
0 = Transmitter disabled  
1 = Transmitter enabled  
RE — Receiver Enable Bit  
0 = Receiver disabled  
1 = Receiver enabled  
RWU — Receiver Wakeup Control Bit  
0 = Normal SCI receiver  
1 = Wakeup enabled and receiver interrupts inhibited  
SBK — Send Break  
At least one character time of break is queued and sent each time SBK is written to 1. As long as the  
SBK bit is set, break characters are queued and sent. More than one break may be sent if the  
transmitter is idle at the time the SBK bit is toggled on and off, as the baud rate clock edge could occur  
between writing the 1 and writing the 0 to SBK.  
0 = Break generator off  
1 = Break codes generated  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
111  
Serial Communications Interface (SCI)  
7.7.4 Serial Communication Status Register  
The SCSR provides inputs to the interrupt logic circuits for generation of the SCI system interrupt.  
Address:  
$102E  
Bit 7  
6
TC  
1
5
RDRF  
0
4
IDLE  
0
3
OR  
0
2
NF  
0
1
FE  
0
Bit 0  
Read:  
Write:  
Reset:  
TDRE  
1
0
= Unimplemented  
Figure 7-6. Serial Communications Status Register (SCSR)  
TDRE — Transmit Data Register Empty Flag  
This flag is set when SCDR is empty. Clear the TDRE flag by reading SCSR with TDRE set and then  
writing to SCDR.  
0 = SCDR busy  
0 = SCDR empty  
TC — Transmit Complete Flag  
This flag is set when the transmitter is idle (no data, preamble, or break transmission in progress).  
Clear the TC flag by reading SCSR with TC set and then writing to SCDR.  
0 = Transmitter busy  
1 = Transmitter idle  
RDRF — Receive Data Register Full Flag  
This flag is set if a received character is ready to be read from SCDR. Clear the RDRF flag by reading  
SCSR with RDRF set and then reading SCDR.  
0 = SCDR empty  
1 = SCDR full  
IDLE — Idle Line Detected Flag  
This flag is set if the RxD line is idle. Once cleared, IDLE is not set again until the RxD line has been  
active and becomes idle again. The IDLE flag is inhibited when RWU = 1. Clear IDLE by reading SCSR  
with IDLE set and then reading SCDR.  
0 = RxD line active  
1 = RxD line idle  
OR — Overrun Error Flag  
OR is set if a new character is received before a previously received character is read from SCDR.  
Clear the OR flag by reading SCSR with OR set and then reading SCDR.  
0 = No overrun  
1 = Overrun detected  
NF — Noise Error Flag  
NF is set if majority sample logic detects anything other than a unanimous decision. Clear NF by  
reading SCSR with NF set and then reading SCDR.  
0 = Unanimous decision  
1 = Noise detected  
M68HC11E Family Data Sheet, Rev. 5.1  
112  
Freescale Semiconductor  
SCI Registers  
FE — Framing Error Flag  
FE is set when a 0 is detected where a stop bit was expected. Clear the FE flag by reading SCSR with  
FE set and then reading SCDR.  
0 = Stop bit detected  
1 = Zero detected  
Bit 0 — Unimplemented  
Always reads 0  
7.7.5 Baud Rate Register  
Use this register to select different baud rates for the SCI system. The SCP[1:0] (SCP[2:0] in  
MC68HC(7)11E20) bits function as a prescaler for the SCR[2:0] bits. Together, these five bits provide  
multiple baud rate combinations for a given crystal frequency. Normally, this register is written once during  
initialization. The prescaler is set to its fastest rate by default out of reset and can be changed at any time.  
Refer to Table 7-1 for normal baud rate selections.  
Address:  
$102B  
Bit 7  
6
SCP2  
0
5
SCP1  
0
4
SCP0  
0
3
RCKB  
0
2
SCR2  
U
1
SCR1  
U
Bit 0  
SCR0  
U
Read:  
Write:  
Reset:  
TCLR  
0
U = Unaffected  
Figure 7-7. Baud Rate Register (BAUD)  
TCLR — Clear Baud Rate Counter Bit (Test)  
SCP[2:0] — SCI Baud Rate Prescaler Select Bits  
NOTE  
SCP2 applies to MC68HC(7)11E20 only. When SCP2 = 1, SCP[1:0] must  
equal 0s. Any other values for SCP[1:0] are not decoded in the prescaler  
and the results are unpredictable. Refer to Figure 7-8 and Figure 7-9.  
RCKB — SCI Baud Rate Clock Check Bit (Test)  
See Table 7-1.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
113  
Serial Communications Interface (SCI)  
Table 7-1. Baud Rate Values  
Crystal Frequency (MHz)  
4.00 4.9152 8.00 10.00 12.00  
Bus Frequency (MHz)  
2.00 2.50 3.00  
Baud  
Set  
Divide  
16.00  
4.00  
Prescale  
Divide  
Prescaler Selects  
SCP2 SCP1 SCP0 SCR2 SCR1 SCR0  
1.00  
1.23  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
1
1
1
1
1
1
1
1
2
4
62500 76800 125000 156250 187500 250000  
31250 38400 62500  
15625 19200 31250  
78125  
39063  
19531  
9766  
93750  
46875  
23438  
11719  
5859  
125000  
62500  
31250  
15625  
7813  
8
7813  
3906  
1953  
977  
9600  
4800  
2400  
1200  
600  
15625  
7813  
3906  
1953  
977  
16  
32  
64  
128  
4883  
2441  
2930  
3906  
488  
1221  
1465  
1953  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
3
3
3
3
3
3
3
3
1
2
4
20833 25600 41667  
10417 12800 20833  
52083  
26042  
13021  
6510  
3255  
1628  
814  
62500  
31250  
15625  
7813  
3906  
1953  
977  
83333  
41667  
20833  
10417  
5208  
2604  
1302  
651  
5208  
2604  
1302  
651  
6400  
3200  
1600  
800  
10417  
5208  
2604  
1302  
651  
8
16  
32  
64  
128  
326  
400  
163  
200  
326  
407  
488  
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
4
4
4
4
4
4
4
4
1
2
4
15625 19200 31250  
39063  
19531  
9766  
4883  
2441  
1221  
610  
46875  
23438  
11719  
5859  
2930  
1465  
732  
62500  
31250  
15625  
7813  
3906  
1953  
977  
7813  
3906  
1953  
977  
9600  
4800  
2400  
1200  
600  
15625  
7813  
3906  
1953  
977  
8
16  
32  
64  
128  
488  
244  
300  
488  
122  
150  
244  
305  
366  
488  
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
13  
13  
13  
13  
13  
13  
13  
13  
1
2
4
4808  
2404  
1202  
601  
300  
150  
75  
5908  
2954  
1477  
738  
369  
185  
92  
9615  
4808  
2404  
1202  
601  
300  
150  
75  
12019  
6010  
3005  
1502  
751  
376  
188  
94  
14423  
7212  
3606  
1803  
901  
451  
225  
113  
19231  
9615  
4808  
2404  
1202  
601  
8
16  
32  
64  
128  
300  
150  
38  
46  
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
39  
39  
39  
39  
39  
39  
39  
39  
1
2
4
1603  
801  
401  
200  
100  
50  
1969  
985  
492  
246  
123  
62  
3205  
1603  
801  
401  
200  
100  
50  
4006  
2003  
1002  
501  
250  
125  
63  
4808  
2404  
1202  
601  
300  
150  
75  
6410  
3205  
1603  
801  
401  
200  
100  
50  
8
16  
32  
64  
128  
25  
13  
31  
15  
25  
31  
38  
Shaded areas reflect standard baud rates.  
On MC68HC(7)11E20 do not set SCP1 or SCP0 when SCP2 is 1.  
M68HC11E Family Data Sheet, Rev. 5.1  
114  
Freescale Semiconductor  
SCI Registers  
SCR[2:0] — SCI Baud Rate Select Bits  
Selects receiver and transmitter bit rate based on output from baud rate prescaler stage. Refer to  
Figure 7-8 and Figure 7-9.  
The prescaler bits, SCP[2:0], determine the highest baud rate, and the SCR[2:0] bits select an  
additional binary submultiple (÷1, ÷2, ÷4, through ÷128) of this highest baud rate. The result of these  
two dividers in series is the 16X receiver baud rate clock. The SCR[2:0] bits are not affected by reset  
and can be changed at any time, although they should not be changed when any SCI transfer is in  
progress.  
Figure 7-8 and Figure 7-9 illustrate the SCI baud rate timing chain. The prescaler select bits determine  
the highest baud rate. The rate select bits determine additional divide by two stages to arrive at the  
receiver timing (RT) clock rate. The baud rate clock is the result of dividing the RT clock by 16.  
EXTAL  
OSCILLATOR  
INTERNAL BUS CLOCK (PH2)  
AND  
CLOCK GENERATOR  
(÷4)  
XTAL  
÷ 3  
÷ 4  
÷ 13  
SCP[1:0]  
1:1  
E
0:0  
0:1  
1:0  
AS  
SCR[2:0]  
0:0:0  
0:0:1  
÷ 2  
÷ 2  
÷ 2  
÷ 2  
÷ 2  
÷ 2  
÷ 2  
0:1:0  
0:1:1  
1:0:0  
1:0:1  
1:1:0  
1:1:1  
÷ 16  
SCI  
TRANSMIT  
BAUD RATE  
(1X)  
SCI  
RECEIVE  
BAUD RATE  
(16X)  
Figure 7-8. SCI Baud Rate Generator Block Diagram  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
115  
Serial Communications Interface (SCI)  
EXTAL  
OSCILLATOR  
INTERNAL BUS CLOCK (PH2)  
AND  
CLOCK GENERATOR  
(÷4)  
XTAL  
÷ 3  
÷ 4  
÷ 13  
÷ 39  
SCP[2:0]*  
1:0:0  
E
0:0:0  
0:0:1  
0:1:0  
0:1:1  
AS  
SCR[2:0]  
0:0:0  
0:0:1  
÷ 2  
÷ 2  
÷ 2  
÷ 2  
÷ 2  
÷ 2  
÷ 2  
0:1:0  
0:1:1  
1:0:0  
1:0:1  
1:1:0  
1:1:1  
÷ 16  
SCI  
TRANSMIT  
BAUD RATE  
(1X)  
SCI  
RECEIVE  
BAUD RATE  
(16X)  
*SCP2 is present only on MC68HC(7)11E20.  
Figure 7-9. MC68HC(7)11E20 SCI Baud Rate  
Generator Block Diagram  
7.8 Status Flags and Interrupts  
The SCI transmitter has two status flags. These status flags can be read by software (polled) to tell when  
the corresponding condition exists. Alternatively, a local interrupt enable bit can be set to enable each of  
these status conditions to generate interrupt requests when the corresponding condition is present.  
Status flags are automatically set by hardware logic conditions, but must be cleared by software, which  
provides an interlock mechanism that enables logic to know when software has noticed the status  
indication. The software clearing sequence for these flags is automatic. Functions that are normally  
performed in response to the status flags also satisfy the conditions of the clearing sequence.  
M68HC11E Family Data Sheet, Rev. 5.1  
116  
Freescale Semiconductor  
Receiver Flags  
TDRE and TC flags are normally set when the transmitter is first enabled (TE set to 1). The TDRE flag  
indicates there is room in the transmit queue to store another data character in the TDR. The TIE bit is  
the local interrupt mask for TDRE. When TIE is 0, TDRE must be polled. When TIE and TDRE are 1, an  
interrupt is requested.  
The TC flag indicates the transmitter has completed the queue. The TCIE bit is the local interrupt mask  
for TC. When TCIE is 0, TC must be polled. When TCIE is 1 and TC is 1, an interrupt is requested.  
Writing a 0 to TE requests that the transmitter stop when it can. The transmitter completes any  
transmission in progress before actually shutting down. Only an MCU reset can cause the transmitter to  
stop and shut down immediately. If TE is written to 0 when the transmitter is already idle, the pin reverts  
to its general-purpose I/O function (synchronized to the bit-rate clock). If anything is being transmitted  
when TE is written to 0, that character is completed before the pin reverts to general-purpose I/O, but any  
other characters waiting in the transmit queue are lost. The TC and TDRE flags are set at the completion  
of this last character, even though TE has been disabled.  
7.9 Receiver Flags  
The SCI receiver has five status flags, three of which can generate interrupt requests. The status flags  
are set by the SCI logic in response to specific conditions in the receiver. These flags can be read (polled)  
at any time by software. Refer to Figure 7-10, which shows SCI interrupt arbitration.  
When an overrun takes place, the new character is lost, and the character that was in its way in the  
parallel RDR is undisturbed. RDRF is set when a character has been received and transferred into the  
parallel RDR. The OR flag is set instead of RDRF if overrun occurs. A new character is ready to be  
transferred into RDR before a previous character is read from RDR.  
The NF and FE flags provide additional information about the character in the RDR, but do not generate  
interrupt requests.  
The last receiver status flag and interrupt source come from the IDLE flag. The RxD line is idle if it has  
constantly been at logic 1 for a full character time. The IDLE flag is set only after the RxD line has been  
busy and becomes idle, which prevents repeated interrupts for the whole time RxD remains idle.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
117  
Serial Communications Interface (SCI)  
BEGIN  
Y
Y
FLAG  
RDRF = 1?  
N
Y
Y
Y
Y
OR = 1?  
N
RIE = 1?  
N
RE = 1?  
N
Y
Y
Y
Y
TDRE = 1?  
N
TE = 1?  
N
TIE = 1?  
N
TC = 1?  
N
TCIE = 1?  
N
Y
Y
IDLE = 1?  
RE = 1?  
N
ILIE = 1?  
N
N
NO  
VALID SCI REQUEST  
VALID SCI REQUEST  
Figure 7-10. Interrupt Source Resolution Within SCI  
M68HC11E Family Data Sheet, Rev. 5.1  
118  
Freescale Semiconductor  
Chapter 8  
Serial Peripheral Interface (SPI)  
8.1 Introduction  
The serial peripheral interface (SPI), an independent serial communications subsystem, allows the MCU  
to communicate synchronously with peripheral devices, such as:  
Frequency synthesizers  
Liquid crystal display (LCD) drivers  
Analog-to-digital (A/D) converter subsystems  
Other microprocessors  
The SPI is also capable of inter-processor communication in a multiple master system. The SPI system  
can be configured as either a master or a slave device. When configured as a master, data transfer rates  
can be as high as one-half the E-clock rate (1.5 Mbits per second for a 3-MHz bus frequency). When  
configured as a slave, data transfers can be as fast as the E-clock rate (3 Mbits per second for a 3-MHz  
bus frequency).  
8.2 Functional Description  
The central element in the SPI system is the block containing the shift register and the read data buffer.  
The system is single buffered in the transmit direction and double buffered in the receive direction. This  
means that new data for transmission cannot be written to the shifter until the previous transfer is  
complete; however, received data is transferred into a parallel read data buffer so the shifter is free to  
accept a second serial character. As long as the first character is read out of the read data buffer before  
the next serial character is ready to be transferred, no overrun condition occurs. A single MCU register  
address is used for reading data from the read data buffer and for writing data to the shifter.  
The SPI status block represents the SPI status functions (transfer complete, write collision, and mode  
fault) performed by the serial peripheral status register (SPSR). The SPI control block represents those  
functions that control the SPI system through the serial peripheral control register (SPCR).  
Refer to Figure 8-1, which shows the SPI block diagram.  
8.3 SPI Transfer Formats  
During an SPI transfer, data is simultaneously transmitted and received. A serial clock line synchronizes  
shifting and sampling of the information on the two serial data lines. A slave select line allows individual  
selection of a slave SPI device; slave devices that are not selected do not interfere with SPI bus activities.  
On a master SPI device, the select line can optionally be used to indicate a multiple master bus  
contention. Refer to Figure 8-2.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
119  
Serial Peripheral Interface (SPI)  
S
MISO  
PD2  
INTERNAL  
MCU CLOCK  
M
MSB  
LSB  
M
S
MOSI  
PD3  
8--BIT SHIFT REGISTER  
DIVIDER  
READ DATA BUFFER  
÷2 ÷4 ÷16 ÷32  
CLOCK  
CLOCK  
LOGIC  
SELECT  
S
SCK  
PD4  
M
SS  
PD5  
MSTR  
SPE  
SPI CONTROL  
SPI STATUS REGISTER  
SPI CONTROL REGISTER  
SPI INTERRUPT  
REQUEST  
INTERNAL  
DATA BUS  
Figure 8-1. SPI Block Diagram  
8.4 Clock Phase and Polarity Controls  
Software can select one of four combinations of serial clock phase and polarity using two bits in the SPI  
control register (SPCR). The clock polarity is specified by the CPOL control bit, which selects an active  
high or active low clock, and has no significant effect on the transfer format. The clock phase (CPHA)  
control bit selects one of two different transfer formats. The clock phase and polarity should be identical  
for the master SPI device and the communicating slave device. In some cases, the phase and polarity  
are changed between transfers to allow a master device to communicate with peripheral slaves having  
different requirements.  
When CPHA equals 0, the SS line must be negated and reasserted between each successive serial byte.  
Also, if the slave writes data to the SPI data register (SPDR) while SS is low, a write collision error results.  
When CPHA equals 1, the SS line can remain low between successive transfers.  
M68HC11E Family Data Sheet, Rev. 5.1  
120  
Freescale Semiconductor  
SPI Signals  
SCK CYCLE #  
1
2
3
4
5
6
7
8
SCK (CPOL = 0)  
SCK (CPOL = 1)  
SAMPLE INPUT  
MSB  
6
5
4
3
2
1
LSB  
(CPHA = 0)  
DATA OUT  
SAMPLE INPUT  
(CPHA = 1) DATA OUT  
SS (TO SLAVE)  
MSB  
6
5
4
3
2
1
LSB  
SLAVE CPHA = 1 TRANSFER IN PROGRESS  
MASTER TRANSFER IN PROGRESS  
3
2
4
SLAVE CPHA = 0 TRANSFER IN PROGRESS  
1
5
1. SS ASSERTED  
2. MASTER WRITES TO SPDR  
3. FIRST SCK EDGE  
4. SPIF SET  
5. SS NEGATED  
Figure 8-2. SPI Transfer Format  
8.5 SPI Signals  
This subsection contains descriptions of the four SPI signals:  
Master in/slave out (MISO)  
Master out/slave in (MOSI)  
Serial clock (SCK)  
Slave select (SS)  
Any SPI output line must have its corresponding data direction bit in DDRD register set. If the DDR bit is  
clear, that line is disconnected from the SPI logic and becomes a general-purpose input. All SPI input lines  
are forced to act as inputs regardless of the state of the corresponding DDR bits in DDRD register.  
8.5.1 Master In/Slave Out  
MISO is one of two unidirectional serial data signals. It is an input to a master device and an output from  
a slave device. The MISO line of a slave device is placed in the high-impedance state if the slave device  
is not selected.  
8.5.2 Master Out/Slave In  
The MOSI line is the second of the two unidirectional serial data signals. It is an output from a master  
device and an input to a slave device. The master device places data on the MOSI line a half-cycle before  
the clock edge that the slave device uses to latch the data.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
121  
Serial Peripheral Interface (SPI)  
8.5.3 Serial Clock  
SCK, an input to a slave device, is generated by the master device and synchronizes data movement in  
and out of the device through the MOSI and MISO lines. Master and slave devices are capable of  
exchanging a byte of information during a sequence of eight clock cycles.  
Four possible timing relationships can be chosen by using control bits CPOL and CPHA in the serial  
peripheral control register (SPCR). Both master and slave devices must operate with the same timing.  
The SPI clock rate select bits, SPR[1:0], in the SPCR of the master device, select the clock rate. In a slave  
device, SPR[1:0] have no effect on the operation of the SPI.  
8.5.4 Slave Select  
The slave select (SS) input of a slave device must be externally asserted before a master device can  
exchange data with the slave device. SS must be low before data transactions and must stay low for the  
duration of the transaction.  
The SS line of the master must be held high. If it goes low, a mode fault error flag (MODF) is set in the  
serial peripheral status register (SPSR). To disable the mode fault circuit, write a 1 in bit 5 of the port D  
data direction register. This sets the SS pin to act as a general-purpose output rather than the dedicated  
input to the slave select circuit, thus inhibiting the mode fault flag. The other three lines are dedicated to  
the SPI whenever the serial peripheral interface is on.  
The state of the master and slave CPHA bits affects the operation of SS. CPHA settings should be  
identical for master and slave. When CPHA = 0, the shift clock is the OR of SS with SCK. In this clock  
phase mode, SS must go high between successive characters in an SPI message. When CPHA = 1, SS  
can be left low between successive SPI characters. In cases where there is only one SPI slave MCU, its  
SS line can be tied to VSS as long as only CPHA = 1 clock mode is used.  
8.6 SPI System Errors  
Two system errors can be detected by the SPI system. The first type of error arises in a multiple-master  
system when more than one SPI device simultaneously tries to be a master. This error is called a mode  
fault. The second type of error, write collision, indicates that an attempt was made to write data to the  
SPDR while a transfer was in progress.  
When the SPI system is configured as a master and the SS input line goes to active low, a mode fault  
error has occurred — usually because two devices have attempted to act as master at the same time. In  
cases where more than one device is concurrently configured as a master, there is a chance of contention  
between two pin drivers. For push-pull CMOS drivers, this contention can cause permanent damage. The  
mode fault mechanism attempts to protect the device by disabling the drivers. The MSTR control bit in the  
SPCR and all four DDRD control bits associated with the SPI are cleared and an interrupt is generated  
subject to masking by the SPIE control bit and the I bit in the CCR.  
Other precautions may need to be taken to prevent driver damage. If two devices are made masters at  
the same time, mode fault does not help protect either one unless one of them selects the other as slave.  
The amount of damage possible depends on the length of time both devices attempt to act as master.  
A write collision error occurs if the SPDR is written while a transfer is in progress. Because the SPDR is  
not double buffered in the transmit direction, writes to SPDR cause data to be written directly into the SPI  
shift register. Because this write corrupts any transfer in progress, a write collision error is generated. The  
transfer continues undisturbed, and the write data that caused the error is not written to the shifter.  
M68HC11E Family Data Sheet, Rev. 5.1  
122  
Freescale Semiconductor  
SPI Registers  
A write collision is normally a slave error because a slave has no control over when a master initiates a  
transfer. A master knows when a transfer is in progress, so there is no reason for a master to generate a  
write-collision error, although the SPI logic can detect write collisions in both master and slave devices.  
The SPI configuration determines the characteristics of a transfer in progress. For a master, a transfer  
begins when data is written to SPDR and ends when SPIF is set. For a slave with CPHA equal to 0, a  
transfer starts when SS goes low and ends when SS returns high. In this case, SPIF is set at the middle  
of the eighth SCK cycle when data is transferred from the shifter to the parallel data register, but the  
transfer is still in progress until SS goes high. For a slave with CPHA equal to 1, transfer begins when the  
SCK line goes to its active level, which is the edge at the beginning of the first SCK cycle. The transfer  
ends in a slave in which CPHA equals 1 when SPIF is set.  
8.7 SPI Registers  
The three SPI registers are:  
Serial peripheral control register (SPCR)  
Serial peripheral status register (SPSR)  
Serial peripheral data register (SPDR)  
These registers provide control, status, and data storage functions.  
8.7.1 Serial Peripheral Control Register  
Address:  
$1028  
Bit 7  
6
SPE  
0
5
DWOM  
0
4
MSTR  
0
3
CPOL  
0
2
CPHA  
1
1
SPR1  
U
Bit 0  
SPR0  
U
Read:  
Write:  
Reset:  
SPIE  
0
U = Unaffected  
Figure 8-3. Serial Peripheral Control Register (SPCR)  
SPIE — Serial Peripheral Interrupt Enable Bit  
Set the SPE bit to 1 to request a hardware interrupt sequence each time the SPIF or MODF status flag  
is set. SPI interrupts are inhibited if this bit is clear or if the I bit in the condition code register is 1.  
0 = SPI system interrupts disabled  
1 = SPI system interrupts enabled  
SPE — Serial Peripheral System Enable Bit  
When the SPE bit is set, the port D bit 2, 3, 4, and 5 pins are dedicated to the SPI function. If the SPI  
is in the master mode and DDRD bit 5 is set, then the port D bit 5 pin becomes a general-purpose  
output instead of the SS input.  
0 = SPI system disabled  
1 = SPI system enabled  
DWOM — Port D Wired-OR Mode Bit  
DWOM affects all port D pins.  
0 = Normal CMOS outputs  
1 = Open-drain outputs  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
123  
Serial Peripheral Interface (SPI)  
MSTR — Master Mode Select Bit  
It is customary to have an external pullup resistor on lines that are driven by open-drain devices.  
0 = Slave mode  
1 = Master mode  
CPOL — Clock Polarity Bit  
When the clock polarity bit is cleared and data is not being transferred, the SCK pin of the master  
device has a steady state low value. When CPOL is set, SCK idles high. Refer to Figure 8-2 and 8.4  
Clock Phase and Polarity Controls.  
CPHA — Clock Phase Bit  
The clock phase bit, in conjunction with the CPOL bit, controls the clock-data relationship between  
master and slave. The CPHA bit selects one of two different clocking protocols. Refer to Figure 8-2  
and 8.4 Clock Phase and Polarity Controls.  
SPR[1:0] — SPI Clock Rate Select Bits  
These two bits select the SPI clock (SCK) rate when the device is configured as master. When the  
device is configured as slave, these bits have no effect. Refer to Table 8-1.  
Table 8-1. SPI Clock Rates  
Frequency at  
E = 1 MHz  
(Baud)  
Frequency at  
E = 2 MHz  
(Baud)  
Frequency at  
E = 3 MHz (  
Baud)  
Frequency at  
E = 4 MHz  
(Baud)  
Divide  
E Clock By  
SPR[1:0]  
0 0  
0 1  
1 0  
1 1  
2
4
500 kHz  
250 kHz  
62.5 kHz  
31.3 kHz  
1.0 MHz  
500 kHz  
125 kHz  
62.5 kHz  
1.5 MHz  
750 kHz  
2 MHz  
1 MHz  
16  
32  
187.5 kHz  
93.8 kHz  
250 kHz  
125 kHz  
8.7.2 Serial Peripheral Status Register  
Address:  
$1029  
Bit 7  
6
5
0
4
MODF  
0
3
0
2
0
1
0
Bit 0  
Read:  
Write:  
Reset:  
SPIF  
0
WCOL  
0
0
= Unimplemented  
Figure 8-4. Serial Peripheral Status Register (SPSR)  
SPIF — SPI Interrupt Complete Flag  
SPIF is set upon completion of data transfer between the processor and the external device. If SPIF  
goes high, and if SPIE is set, a serial peripheral interrupt is generated. To clear the SPIF bit, read the  
SPSR with SPIF set, then access the SPDR. Unless SPSR is read (with SPIF set) first, attempts to  
write SPDR are inhibited.  
WCOL — Write Collision Bit  
Clearing the WCOL bit is accomplished by reading the SPSR (with WCOL set) followed by an access  
of SPDR. Refer to 8.5.4 Slave Select and 8.6 SPI System Errors.  
0 = No write collision  
1 = Write collision  
M68HC11E Family Data Sheet, Rev. 5.1  
124  
Freescale Semiconductor  
SPI Registers  
Bit 5 — Unimplemented  
Always reads 0  
MODF — Mode Fault Bit  
To clear the MODF bit, read the SPSR (with MODF set), then write to the SPCR. Refer to 8.5.4 Slave  
Select and 8.6 SPI System Errors.  
0 = No mode fault  
1 = Mode fault  
Bits [3:0] — Unimplemented  
Always read 0  
8.7.3 Serial Peripheral Data I/O Register  
The SPDR is used when transmitting or receiving data on the serial bus. Only a write to this register  
initiates transmission or reception of a byte, and this only occurs in the master device. At the completion  
of transferring a byte of data, the SPIF status bit is set in both the master and slave devices.  
A read of the SPDR is actually a read of a buffer. To prevent an overrun and the loss of the byte that  
caused the overrun, the first SPIF must be cleared by the time a second transfer of data from the shift  
register to the read buffer is initiated.  
Address:  
$102A  
Bit 7  
6
5
4
3
2
1
Bit 0  
Bit 0  
Read:  
Write:  
Reset:  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Indeterminate after reset  
Figure 8-5. Serial Peripheral Data I/O Register (SPDR)  
SPI is double buffered in and single buffered out.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
125  
Serial Peripheral Interface (SPI)  
M68HC11E Family Data Sheet, Rev. 5.1  
126  
Freescale Semiconductor  
Chapter 9  
Timing Systems  
9.1 Introduction  
The M68HC11 timing system is composed of five clock divider chains. The main clock divider chain  
includes a 16-bit free-running counter, which is driven by a programmable prescaler. The main timer’s  
programmable prescaler provides one of the four clocking rates to drive the 16-bit counter. Two prescaler  
control bits select the prescale rate.  
The prescaler output divides the system clock by 1, 4, 8, or 16. Taps off of this main clocking chain drive  
circuitry that generates the slower clocks used by the pulse accumulator, the real-time interrupt (RTI), and  
the computer operating properly (COP) watchdog subsystems, also described in this section. Refer to  
Figure 9-1.  
All main timer system activities are referenced to this free-running counter. The counter begins  
incrementing from $0000 as the MCU comes out of reset and continues to the maximum count, $FFFF.  
At the maximum count, the counter rolls over to $0000, sets an overflow flag, and continues to increment.  
As long as the MCU is running in a normal operating mode, there is no way to reset, change, or interrupt  
the counting. The capture/compare subsystem features three input capture channels, four output  
compare channels, and one channel that can be selected to perform either input capture or output  
compare. Each of the three input capture functions has its own 16-bit input capture register (time capture  
latch) and each of the output compare functions has its own 16-bit compare register. All timer functions,  
including the timer overflow and RTI, have their own interrupt controls and separate interrupt vectors.  
The pulse accumulator contains an 8-bit counter and edge select logic. The pulse accumulator can  
operate in either event counting mode or gated time accumulation mode. During event counting mode,  
the pulse accumulator’s 8-bit counter increments when a specified edge is detected on an input signal.  
During gated time accumulation mode, an internal clock source increments the 8-bit counter while an  
input signal has a predetermined logic level.  
The real-time interrupt (RTI) is a programmable periodic interrupt circuit that permits pacing the execution  
of software routines by selecting one of four interrupt rates.  
The COP watchdog clock input (E ÷ 215) is tapped off of the free-running counter chain. The COP  
automatically times out unless it is serviced within a specific time by a program reset sequence. If the COP  
is allowed to time out, a reset is generated, which drives the RESET pin low to reset the MCU and the  
external system. Refer to Table 9-1 for crystal-related frequencies and periods.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
127  
Timing Systems  
OSCILLATOR AND  
CLOCK GENERATOR  
(DIVIDE BY FOUR)  
AS  
E CLOCK  
INTERNAL BUS CLOCK (PH2)  
SPI  
PRESCALER  
(÷ 2, 4, 16, 32)  
SPR[1:0]  
PRESCALER  
(÷ 1, 2, 4,....128)  
SCR[2:0]  
PRESCALER  
(÷ 1, 3, 4, 13)  
SCP[1:0]  
÷39  
SCI RECEIVER CLOCK  
SCI TRANSMIT CLOCK  
PULSE ACCUMULATOR  
SCP2*  
÷16  
E ÷ 26  
PRESCALER  
÷ 1, 2, 4, 8)  
RTR[1:0]  
E ÷ 213  
REAL-TIME INTERRUPT  
÷ 4  
E÷215  
PRESCALER  
(÷ 1, 4, 8, 16)  
PR[1:0]  
PRESCALER  
(÷1, 4, 16, 64)  
CR[1:0]  
TOF  
TCNT  
FF1  
FF2  
S
R
Q
Q
S
R
Q
Q
FORCE  
COP  
RESET  
IC/OC  
CLEAR COP  
TIMER  
SYSTEM  
RESET  
E SERIES TIM DIV CHAIN  
* SCP2 present on MC68HC(7)11E20 only  
Figure 9-1. Timer Clock Divider Chains  
M68HC11E Family Data Sheet, Rev. 5.1  
128  
Freescale Semiconductor  
Timer Structure  
Table 9-1. Timer Summary  
XTAL Frequencies  
4.0 MHz  
8.0 MHz  
2.0 MHz  
500 ns  
12.0 MHz  
Other Rates  
(E)  
1.0 MHz  
1000 ns  
3.0 MHz  
333 ns  
Control Bits  
PR1, PR0  
(1/E)  
Main Timer Count Rates  
0 0  
1 count —  
overflow —  
(E/1)  
(E/216  
1000 ns  
65.536 ms  
500 ns  
32.768 ms  
333 ns  
21.845 ms  
)
)
)
0 1  
1 count —  
overflow —  
(E/4)  
(E/218  
4.0 µs  
2.0 µs  
1.333 µs  
262.14 ms  
131.07 ms  
87.381 ms  
1 0  
1 count —  
overflow —  
(E/8)  
(E/219  
8.0 µs  
524.29 ms  
4.0 µs  
262.14 ms  
2.667 µs  
174.76 ms  
1 1  
1 count —  
overflow —  
(E/16)  
(E/220  
16.0 µs  
1.049 s  
8.0 µs  
524.29 ms  
5.333 µs  
349.52 ms  
)
9.2 Timer Structure  
Figure 9-2 shows the capture/compare system block diagram. The port A pin control block includes logic  
for timer functions and for general-purpose I/O. For pins PA3, PA2, PA1, and PA0, this block contains  
both the edge-detection logic and the control logic that enables the selection of which edge triggers an  
input capture. The digital level on PA[3:0] can be read at any time (read PORTA register), even if the pin  
is being used for the input capture function. Pins PA[6:3] are used for either general-purpose I/O, or as  
output compare pins. When one of these pins is being used for an output compare function, it cannot be  
written directly as if it were a general-purpose output. Each of the output compare functions (OC[5:2]) is  
related to one of the port A output pins. Output compare one (OC1) has extra control logic, allowing it  
optional control of any combination of the PA[7:3] pins. The PA7 pin can be used as a general-purpose  
I/O pin, as an input to the pulse accumulator, or as an OC1 output pin.  
9.3 Input Capture  
The input capture function records the time an external event occurs by latching the value of the  
free-running counter when a selected edge is detected at the associated timer input pin. Software can  
store latched values and use them to compute the periodicity and duration of events. For example, by  
storing the times of successive edges of an incoming signal, software can determine the period and pulse  
width of a signal. To measure period, two successive edges of the same polarity are captured. To  
measure pulse width, two alternate polarity edges are captured.  
In most cases, input capture edges are asynchronous to the internal timer counter, which is clocked  
relative to an internal clock (PH2). These asynchronous capture requests are synchronized to PH2 so that  
the latching occurs on the opposite half cycle of PH2 from when the timer counter is being incremented.  
This synchronization process introduces a delay from when the edge occurs to when the counter value is  
detected. Because these delays offset each other when the time between two edges is being measured,  
the delay can be ignored. When an input capture is being used with an output compare, there is a similar  
delay between the actual compare point and when the output pin changes state.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
129  
Timing Systems  
PRESCALER  
DIVIDE BY  
TCNT (HI)  
TCNT (LO)  
TOI  
9
1, 4, 8, OR 16  
MCU  
16-BIT FREE-RUNNING  
COUNTER  
TOF  
PR1  
PR0  
E CLK  
TAPS FOR RTI,  
COP WATCHDOG, AND  
PULSE ACCUMULATOR  
INTERRUPT REQUESTS  
(FURTHER QUALIFIED BY  
I BIT IN CCR)  
16-BIT TIMER BUS  
TO PULSE  
ACCUMULATOR  
OC1I  
PIN  
FUNCTIONS  
8
16-BIT COMPARATOR =  
OC1F  
OC2F  
OC3F  
PA7/OC1/  
PAI  
TOC1 (HI) TOC1 (LO)  
BIT 7  
BIT 6  
FOC1  
FOC2  
FOC3  
FOC4  
FOC5  
OC2I  
OC3I  
OC4I  
I4/O5I  
7
6
5
4
16-BIT COMPARATOR =  
PA6/OC2/  
OC1  
TOC2 (HI) TOC2 (LO)  
16-BIT COMPARATOR =  
PA5/OC3/  
OC1  
BIT 5  
BIT 4  
BIT 3  
TOC3 (HI) TOC3 (LO)  
16-BIT COMPARATOR =  
OC4F  
OC5  
PA4/OC4/  
OC1  
TOC4 (HI) TOC4 (LO)  
16-BIT COMPARATOR =  
TI4/O5 (HI) TI4/O5 (LO)  
16-BIT LATCH CLK  
PA3/OC5/  
IC4/OC1  
I4/O5F  
IC4  
CFORC  
FORCE OUTPUT  
COMPARE  
I4/O5  
IC1I  
IC2I  
IC3I  
3
2
1
CLK  
TIC1 (LO)  
BIT 2  
BIT 1  
BIT 0  
16-BIT LATCH  
IC1F  
PA2/IC1  
PA1/IC2  
PA0/IC3  
TIC1 (HI)  
CLK  
16-BIT LATCH  
IC2F  
IC3F  
TIC2 (HI)  
TIC2 (LO)  
CLK  
16-BIT LATCH  
TIC3 (HI)  
TIC3 (LO)  
TFLG 1  
STATUS  
FLAGS  
TMSK 1  
INTERRUPT  
ENABLES  
PORT A  
PIN CONTROL  
Figure 9-2. Capture/Compare Block Diagram  
M68HC11E Family Data Sheet, Rev. 5.1  
130  
Freescale Semiconductor  
Input Capture  
The control and status bits that implement the input capture functions are contained in:  
Pulse accumulator control register (PACTL)  
Timer control 2 register (TCTL2)  
Timer interrupt mask 1 register (TMSK1)  
Timer interrupt flag 2 register (TFLG1)  
To configure port A bit 3 as an input capture, clear the DDRA3 bit of the PACTL register. Note that this bit  
is cleared out of reset. To enable PA3 as the fourth input capture, set the I4/O5 bit in the PACTL register.  
Otherwise, PA3 is configured as a fifth output compare out of reset, with bit I4/O5 being cleared. If the  
DDRA3 bit is set (configuring PA3 as an output), and IC4 is enabled, then writes to PA3 cause edges on  
the pin to result in input captures. Writing to TI4/O5 has no effect when the TI4/O5 register is acting as IC4.  
9.3.1 Timer Control Register 2  
Use the control bits of this register to program input capture functions to detect a particular edge polarity  
on the corresponding timer input pin. Each of the input capture functions can be independently configured  
to detect rising edges only, falling edges only, any edge (rising or falling), or to disable the input capture  
function. The input capture functions operate independently of each other and can capture the same  
TCNT value if the input edges are detected within the same timer count cycle.  
Address:  
$1021  
Bit 7  
6
EDG4A  
0
5
EDG1B  
0
4
EDG1A  
0
3
EDG2B  
0
2
EDG2A  
0
1
EDG3B  
0
Bit 0  
EDG3A  
0
Read:  
Write:  
Reset:  
EDG4B  
0
Figure 9-3. Timer Control Register 2 (TCTL2)  
EDGxB and EDGxA — Input Capture Edge Control Bits  
There are four pairs of these bits. Each pair is cleared to 0 by reset and must be encoded to configure  
the corresponding input capture edge detector circuit. IC4 functions only if the I4/O5 bit in the PACTL  
register is set. Refer to Table 9-2 for timer control configuration.  
Table 9-2. Timer Control Configuration  
EDGxB  
EDGxA  
Configuration  
Capture disabled  
0
0
1
1
0
1
0
1
Capture on rising edges only  
Capture on falling edges only  
Capture on any edge  
9.3.2 Timer Input Capture Registers  
When an edge has been detected and synchronized, the 16-bit free-running counter value is transferred  
into the input capture register pair as a single 16-bit parallel transfer. Timer counter value captures and  
timer counter incrementing occur on opposite half-cycles of the phase 2 clock so that the count value is  
stable whenever a capture occurs. The timer input capture registers are not affected by reset. Input  
capture values can be read from a pair of 8-bit read-only registers. A read of the high-order byte of an  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
131  
Timing Systems  
input capture register pair inhibits a new capture transfer for one bus cycle. If a double-byte read  
instruction, such as load double accumulator D (LDD), is used to read the captured value, coherency is  
assured. When a new input capture occurs immediately after a high-order byte read, transfer is delayed  
for an additional cycle but the value is not lost.  
Register name: Timer Input Capture 1 Register (High) Address: $1010  
Bit 7  
6
5
4
3
2
1
Bit 0  
Bit 8  
Read:  
Write:  
Reset:  
Bit 15  
Bit 14  
Bit 13  
Bit 12  
Bit 11  
Bit 10  
Bit 9  
Indeterminate after reset  
Register name: Timer Input Capture 1 Register (Low) Address: $1011  
Bit 7  
6
5
4
3
2
1
Bit 0  
Bit 0  
Read:  
Write:  
Reset:  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Indeterminate after reset  
Figure 9-4. Timer Input Capture 1 Register Pair (TIC1)  
Register name: Timer Input Capture 2 Register (High) Address: $1012  
Bit 7  
6
5
4
3
2
1
Bit 0  
Bit 8  
Read:  
Write:  
Reset:  
Bit 15  
Bit 14  
Bit 13  
Bit 12  
Bit 11  
Bit 10  
Bit 9  
Indeterminate after reset  
Register name: Timer Input Capture 2 Register (Low) Address: $1013  
Bit 7  
6
5
4
3
2
1
Bit 0  
Bit 0  
Read:  
Write:  
Reset:  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Indeterminate after reset  
Figure 9-5. Timer Input Capture 2 Register Pair (TIC2)  
Register name: Timer Input Capture 3 Register (High) Address: $1014  
Bit 7  
6
5
4
3
2
1
Bit 0  
Bit 8  
Read:  
Write:  
Reset:  
Bit 15  
Bit 14  
Bit 13  
Bit 12  
Bit 11  
Bit 10  
Bit 9  
Indeterminate after reset  
Register name: Timer Input Capture 3 Register (Low) Address: $1015  
Bit 7  
6
5
4
3
2
1
Bit 0  
Bit 0  
Read:  
Write:  
Reset:  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Indeterminate after reset  
Figure 9-6. Timer Input Capture 3 Register Pair (TIC3)  
M68HC11E Family Data Sheet, Rev. 5.1  
132  
Freescale Semiconductor  
Output Compare  
9.3.3 Timer Input Capture 4/Output Compare 5 Register  
Use TI4/O5 as either an input capture register or an output compare register, depending on the function  
chosen for the PA3 pin. To enable it as an input capture pin, set the I4/O5 bit in the pulse accumulator  
control register (PACTL) to logic level 1. To use it as an output compare register, set the I4/O5 bit to a  
logic level 0. Refer to 9.7 Pulse Accumulator.  
Register name: Timer Input Capture 4/Output Compare 5 (High) Address: $101E  
Bit 7  
Bit 15  
1
6
Bit 14  
1
5
Bit 13  
1
4
Bit 12  
1
3
Bit 11  
1
2
Bit 10  
1
1
Bit 9  
1
Bit 0  
Bit 8  
1
Read:  
Write:  
Reset:  
Register name: Timer Input Capture 4/Output Compare 5 (Low) Address: $101F  
Bit 7  
Bit 7  
1
6
Bit 6  
1
5
Bit 5  
1
4
Bit 4  
1
3
Bit 3  
1
2
Bit 2  
1
1
Bit 1  
1
Bit 0  
Bit 0  
1
Read:  
Write:  
Reset:  
Figure 9-7. Timer Input Capture 4/Output  
Compare 5 Register Pair (TI4/O5)  
9.4 Output Compare  
Use the output compare (OC) function to program an action to occur at a specific time — when the 16-bit  
counter reaches a specified value. For each of the five output compare functions, there is a separate  
16-bit compare register and a dedicated 16-bit comparator. The value in the compare register is  
compared to the value of the free-running counter on every bus cycle. When the compare register  
matches the counter value, an output compare status flag is set. The flag can be used to initiate the  
automatic actions for that output compare function.  
To produce a pulse of a specific duration, write a value to the output compare register that represents the  
time the leading edge of the pulse is to occur. The output compare circuit is configured to set the  
appropriate output either high or low, depending on the polarity of the pulse being produced. After a match  
occurs, the output compare register is reprogrammed to change the output pin back to its inactive level  
at the next match. A value representing the width of the pulse is added to the original value, and then  
written to the output compare register. Because the pin state changes occur at specific values of the  
free-running counter, the pulse width can be controlled accurately at the resolution of the free-running  
counter, independent of software latencies. To generate an output signal of a specific frequency and duty  
cycle, repeat this pulse-generating procedure.  
The five 16-bit read/write output compare registers are: TOC1, TOC2, TOC3, and TOC4, and the TI4/O5.  
TI4/O5 functions under software control as either IC4 or OC5. Each of the OC registers is set to $FFFF  
on reset. A value written to an OC register is compared to the free-running counter value during each  
E-clock cycle. If a match is found, the particular output compare flag is set in timer interrupt flag register  
1 (TFLG1). If that particular interrupt is enabled in the timer interrupt mask register 1 (TMSK1), an interrupt  
is generated. In addition to an interrupt, a specified action can be initiated at one or more timer output  
pins. For OC[5:2], the pin action is controlled by pairs of bits (OMx and OLx) in the TCTL1 register. The  
output action is taken on each successful compare, regardless of whether or not the OCxF flag in the  
TFLG1 register was previously cleared.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
133  
Timing Systems  
OC1 is different from the other output compares in that a successful OC1 compare can affect any or all  
five of the OC pins. The OC1 output action taken when a match is found is controlled by two 8-bit registers  
with three bits unimplemented: the output compare 1 mask register, OC1M, and the output compare 1  
data register, OC1D. OC1M specifies which port A outputs are to be used, and OC1D specifies what data  
is placed on these port pins.  
9.4.1 Timer Output Compare Registers  
All output compare registers are 16-bit read-write. Each is initialized to $FFFF at reset. If an output  
compare register is not used for an output compare function, it can be used as a storage location. A write  
to the high-order byte of an output compare register pair inhibits the output compare function for one bus  
cycle. This inhibition prevents inappropriate subsequent comparisons. Coherency requires a complete  
16-bit read or write. However, if coherency is not needed, byte accesses can be used.  
For output compare functions, write a comparison value to output compare registers TOC1–TOC4 and  
TI4/O5. When TCNT value matches the comparison value, specified pin actions occur.  
Register name: Timer Output Compare 1 Register (High) Address: $1016  
Bit 7  
Bit 15  
1
6
Bit 14  
1
5
Bit 13  
1
4
Bit 12  
1
3
Bit 11  
1
2
Bit 10  
1
1
Bit 9  
1
Bit 0  
Bit 8  
1
Read:  
Write:  
Reset:  
Register name: Timer Output Compare 1 Register (Low) Address: $1017  
Bit 7  
Bit 7  
1
6
Bit 6  
1
5
Bit 5  
1
4
Bit 4  
1
3
Bit 3  
1
2
Bit 2  
1
1
Bit 1  
1
Bit 0  
Bit 0  
1
Read:  
Write:  
Reset:  
Figure 9-8. Timer Output Compare 1 Register Pair (TOC1)  
Register name: Timer Output Compare 2 Register (High) Address: $1018  
Bit 7  
Bit 15  
1
6
Bit 14  
1
5
Bit 13  
1
4
Bit 12  
1
3
Bit 11  
1
2
Bit 10  
1
1
Bit 9  
1
Bit 0  
Bit 8  
1
Read:  
Write:  
Reset:  
Register name: Timer Output Compare 2 Register (Low) Address: $1019  
Bit 7  
Bit 7  
1
6
Bit 6  
1
5
Bit 5  
1
4
Bit 4  
1
3
Bit 3  
1
2
Bit 2  
1
1
Bit 1  
1
Bit 0  
Bit 0  
1
Read:  
Write:  
Reset:  
Figure 9-9. Timer Output Compare 2 Register Pair (TOC2)  
M68HC11E Family Data Sheet, Rev. 5.1  
134  
Freescale Semiconductor  
Output Compare  
Register name: Timer Output Compare 3 Register (High) Address: $101A  
Bit 7  
Bit 15  
1
6
Bit 14  
1
5
Bit 13  
1
4
Bit 12  
1
3
Bit 11  
1
2
Bit 10  
1
1
Bit 9  
1
Bit 0  
Read:  
Write:  
Reset:  
Bit 8  
1
Register name: Timer Output Compare 3 Register (Low) Address: $101B  
Bit 7  
Bit 7  
1
6
Bit 6  
1
5
Bit 5  
1
4
Bit 4  
1
3
Bit 3  
1
2
Bit 2  
1
1
Bit 1  
1
Bit 0  
Bit 0  
1
Read:  
Write:  
Reset:  
Figure 9-10. Timer Output Compare 3 Register Pair (TOC3)  
Register name: Timer Output Compare 4 Register (High) Address: $101C  
Bit 7  
Bit 15  
1
6
Bit 14  
1
5
Bit 13  
1
4
Bit 12  
1
3
Bit 11  
1
2
Bit 10  
1
1
Bit 9  
1
Bit 0  
Bit 8  
1
Read:  
Write:  
Reset:  
Register name: Timer Output Compare 4 Register (Low) Address: $101D  
Bit 7  
Bit 7  
1
6
Bit 6  
1
5
Bit 5  
1
4
Bit 4  
1
3
Bit 3  
1
2
Bit 2  
1
1
Bit 1  
1
Bit 0  
Bit 0  
1
Read:  
Write:  
Reset:  
Figure 9-11. Timer Output Compare 4 Register Pair (TOC4)  
9.4.2 Timer Compare Force Register  
The CFORC register allows forced early compares. FOC[1:5] correspond to the five output compares.  
These bits are set for each output compare that is to be forced. The action taken as a result of a forced  
compare is the same as if there were a match between the OCx register and the free-running counter,  
except that the corresponding interrupt status flag bits are not set. The forced channels trigger their  
programmed pin actions to occur at the next timer count transition after the write to CFORC.  
The CFORC bits should not be used on an output compare function that is programmed to toggle its  
output on a successful compare because a normal compare that occurs immediately before or after the  
force can result in an undesirable operation.  
Address:  
$100B  
Bit 7  
6
FOC2  
0
5
FOC3  
0
4
FOC4  
0
3
FOC5  
0
2
0
1
0
Bit 0  
Read:  
Write:  
Reset:  
FOC1  
0
0
= Unimplemented  
Figure 9-12. Timer Compare Force Register (CFORC)  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
135  
Timing Systems  
FOC[1:5] — Force Output Comparison Bit  
When the FOC bit associated with an output compare circuit is set, the output compare circuit  
immediately performs the action it is programmed to do when an output match occurs.  
0 = Not affected  
1 = Output x action occurs  
Bits [2:0] — Unimplemented  
Always read 0  
9.4.3 Output Compare Mask Register  
Use OC1M with OC1 to specify the bits of port A that are affected by a successful OC1 compare. The bits  
of the OC1M register correspond to PA[7:3].  
Address:  
$100C  
Bit 7  
6
OC1M6  
0
5
OC1M5  
0
4
OC1M4  
0
3
OC1M3  
0
2
0
1
0
Bit 0  
Read:  
Write:  
Reset:  
OC1M7  
0
0
= Unimplemented  
Figure 9-13. Output Compare 1 Mask Register (OC1M)  
OC1M[7:3] — Output Compare Masks  
0 = OC1 disabled  
1 = OC1 enabled to control the corresponding pin of port A  
Bits [2:0] — Unimplemented  
Always read 0  
9.4.4 Output Compare Data Register  
Use this register with OC1 to specify the data that is to be stored on the affected pin of port A after a  
successful OC1 compare. When a successful OC1 compare occurs, a data bit in OC1D is stored in the  
corresponding bit of port A for each bit that is set in OC1M.  
Address:  
$100D  
Bit 7  
6
OC1D6  
0
5
OC1D5  
0
4
OC1D4  
0
3
OC1D3  
0
2
0
1
0
Bit 0  
Read:  
Write:  
Reset:  
OC1D7  
0
0
= Unimplemented  
Figure 9-14. Output Compare 1 Data Register (OC1D)  
If OC1Mx is set, data in OC1Dx is output to port A bit x on successful OC1 compares.  
Bits [2:0] — Unimplemented  
Always read 0  
M68HC11E Family Data Sheet, Rev. 5.1  
136  
Freescale Semiconductor  
Output Compare  
9.4.5 Timer Counter Register  
The 16-bit read-only TCNT register contains the prescaled value of the 16-bit timer. A full counter read  
addresses the most significant byte (MSB) first. A read of this address causes the least significant byte  
(LSB) to be latched into a buffer for the next CPU cycle so that a double-byte read returns the full 16-bit  
state of the counter at the time of the MSB read cycle.  
Register name: Timer Counter Register (High) Address: $100E  
Bit 7  
6
5
4
3
2
1
Bit 0  
Bit 8  
Read:  
Write:  
Reset:  
Bit 15  
Bit 14  
Bit 13  
Bit 12  
Bit 11  
Bit 10  
Bit 9  
0
0
0
0
0
0
0
0
Register name: Timer Counter Register (Low) Address: $100F  
Bit 7  
Bit 7  
6
5
4
3
2
1
Bit 0  
Bit 0  
Read:  
Write:  
Reset:  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
0
0
0
0
0
0
0
0
= Unimplemented  
Figure 9-15. Timer Counter Register (TCNT)  
9.4.6 Timer Control Register 1  
The bits of this register specify the action taken as a result of a successful OCx compare.  
Address:  
$1020  
Bit 7  
6
OL2  
0
5
OM3  
0
4
OL3  
0
3
OM4  
0
2
OL4  
0
1
OM5  
0
Bit 0  
OL5  
0
Read:  
Write:  
Reset:  
OM2  
0
Figure 9-16. Timer Control Register 1 (TCTL1)  
OM[2:5] — Output Mode Bits  
OL[2:5] — Output Level Bits  
These control bit pairs are encoded to specify the action taken after a successful OCx compare. OC5  
functions only if the I4/O5 bit in the PACTL register is clear. Refer to Table 9-3 for the coding.  
Table 9-3. Timer Output Compare Actions  
OMx  
OLx  
Action Taken on Successful Compare  
Timer disconnected from output pin logic  
Toggle OCx output line  
0
0
1
1
0
1
0
1
Clear OCx output line to 0  
Set OCx output line to 1  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
137  
Timing Systems  
9.4.7 Timer Interrupt Mask 1 Register  
Use this 8-bit register to enable or inhibit the timer input capture and output compare interrupts.  
Address:  
$1022  
Bit 7  
6
OC2I  
0
5
OC3I  
0
4
OC4I  
0
3
I4/O5I  
0
2
IC1I  
0
1
IC2I  
0
Bit 0  
IC3I  
0
Read:  
Write:  
Reset:  
OC1I  
0
Figure 9-17. Timer Interrupt Mask 1 Register (TMSK1)  
OC1I–OC4I — Output Compare x Interrupt Enable Bits  
If the OCxI enable bit is set when the OCxF flag bit is set, a hardware interrupt sequence is requested.  
I4/O5I — Input Capture 4/Output Compare 5 Interrupt Enable Bit  
When I4/O5 in PACTL is 1, I4/O5I is the input capture 4 interrupt enable bit. When I4/O5 in PACTL is  
0, I4/O5I is the output compare 5 interrupt enable bit.  
IC1I–IC3I — Input Capture x Interrupt Enable Bits  
If the ICxI enable bit is set when the ICxF flag bit is set, a hardware interrupt sequence is requested.  
NOTE  
Bits in TMSK1 correspond bit for bit with flag bits in TFLG1. Bits in TMSK1  
enable the corresponding interrupt sources.  
9.4.8 Timer Interrupt Flag 1 Register  
Bits in this register indicate when timer system events have occurred. Coupled with the bits of TMSK1,  
the bits of TFLG1 allow the timer subsystem to operate in either a polled or interrupt driven system. Each  
bit of TFLG1 corresponds to a bit in TMSK1 in the same position.  
Address:  
$1023  
Bit 7  
6
OC2F  
0
5
OC3F  
0
4
OC4F  
0
3
I4/O5F  
0
2
IC1F  
0
1
IC2F  
0
Bit 0  
IC3F  
0
Read:  
Write:  
Reset:  
OC1F  
0
Figure 9-18. Timer Interrupt Flag 1 Register (TFLG1)  
Clear flags by writing a 1 to the corresponding bit position(s).  
OC1F–OC4F — Output Compare x Flag  
Set each time the counter matches output compare x value  
I4/O5F — Input Capture 4/Output Compare 5 Flag  
Set by IC4 or OC5, depending on the function enabled by I4/O5 bit in PACTL  
IC1F–IC3F — Input Capture x Flag  
Set each time a selected active edge is detected on the ICx input line  
M68HC11E Family Data Sheet, Rev. 5.1  
138  
Freescale Semiconductor  
Output Compare  
9.4.9 Timer Interrupt Mask 2 Register  
Use this 8-bit register to enable or inhibit timer overflow and real-time interrupts. The timer prescaler  
control bits are included in this register.  
Address:  
$1024  
Bit 7  
6
RTII  
0
5
PAOVI  
0
4
PAII  
0
3
0
2
0
1
PR1  
0
Bit 0  
PR0  
0
Read:  
Write:  
Reset:  
TOI  
0
= Unimplemented  
Figure 9-19. Timer Interrupt Mask 2 Register (TMSK2)  
TOI — Timer Overflow Interrupt Enable Bit  
0 = TOF interrupts disabled  
1 = Interrupt requested when TOF is set to 1  
RTII — Real-Time Interrupt Enable Bit  
Refer to 9.5 Real-Time Interrupt (RTI).  
PAOVI — Pulse Accumulator Overflow Interrupt Enable Bit  
Refer to 9.7.3 Pulse Accumulator Status and Interrupt Bits.  
PAII — Pulse Accumulator Input Edge Interrupt Enable Bit  
Refer to 9.7.3 Pulse Accumulator Status and Interrupt Bits.  
Bits [3:2] — Unimplemented  
Always read 0  
PR[1:0] — Timer Prescaler Select Bits  
These bits are used to select the prescaler divide-by ratio. In normal modes, PR[1:0] can be written  
only once, and the write must be within 64 cycles after reset. Refer to Table 9-1 and Table 9-4 for  
specific timing values.  
Table 9-4. Timer Prescale  
PR[1:0]  
0 0  
Prescaler  
1
4
0 1  
1 0  
8
1 1  
16  
NOTE  
Bits in TMSK2 correspond bit for bit with flag bits in TFLG2. Bits in TMSK2  
enable the corresponding interrupt sources.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
139  
Timing Systems  
9.4.10 Timer Interrupt Flag Register 2  
Bits in this register indicate when certain timer system events have occurred. Coupled with the four  
high-order bits of TMSK2, the bits of TFLG2 allow the timer subsystem to operate in either a polled or  
interrupt driven system. Each bit of TFLG2 corresponds to a bit in TMSK2 in the same position.  
Address:  
$1025  
Bit 7  
6
RTIF  
0
5
PAOVF  
0
4
PAIF  
0
3
0
2
0
1
0
Bit 0  
Read:  
Write:  
Reset:  
TOF  
0
0
= Unimplemented  
Figure 9-20. Timer Interrupt Flag 2 Register (TFLG2)  
Clear flags by writing a 1 to the corresponding bit position(s).  
TOF — Timer Overflow Interrupt Flag  
Set when TCNT changes from $FFFF to $0000  
RTIF — Real-Time (Periodic) Interrupt Flag  
Refer to 9.5 Real-Time Interrupt (RTI).  
PAOVF — Pulse Accumulator Overflow Interrupt Flag  
Refer to 9.7 Pulse Accumulator.  
PAIF — Pulse Accumulator Input Edge Interrupt Flag  
Refer to 9.7 Pulse Accumulator.  
Bits [3:0] — Unimplemented  
Always read 0  
9.5 Real-Time Interrupt (RTI)  
The real-time interrupt (RTI) feature, used to generate hardware interrupts at a fixed periodic rate, is  
controlled and configured by two bits (RTR1 and RTR0) in the pulse accumulator control (PACTL)  
register. The RTII bit in the TMSK2 register enables the interrupt capability. The four different rates  
available are a product of the MCU oscillator frequency and the value of bits RTR[1:0]. Refer to Table 9-5,  
which shows the periodic real-time interrupt rates.  
Table 9-5. RTI Rates  
RTR[1:0]  
0 0  
E = 3 MHz  
2.731 ms  
5.461 ms  
10.923 ms  
21.845 ms  
E = 2 MHz  
4.096 ms  
8.192 ms  
16.384 ms  
32.768 ms  
E = 1 MHz  
8.192 ms  
E = X MHz  
(E/213  
(E/214  
(E/215  
(E/216  
)
)
)
)
0 1  
16.384 ms  
32.768 ms  
65.536 ms  
1 0  
1 1  
The clock source for the RTI function is a free-running clock that cannot be stopped or interrupted except  
by reset. This clock causes the time between successive RTI timeouts to be a constant that is  
M68HC11E Family Data Sheet, Rev. 5.1  
140  
Freescale Semiconductor  
Real-Time Interrupt (RTI)  
independent of the software latencies associated with flag clearing and service. For this reason, an RTI  
period starts from the previous timeout, not from when RTIF is cleared.  
Every timeout causes the RTIF bit in TFLG2 to be set, and if RTII is set, an interrupt request is generated.  
After reset, one entire RTI period elapses before the RTIF is set for the first time. Refer to the 9.4.9 Timer  
Interrupt Mask 2 Register, 9.5.2 Timer Interrupt Flag Register 2, and 9.5.3 Pulse Accumulator Control  
Register.  
9.5.1 Timer Interrupt Mask Register 2  
This register contains the real-time interrupt enable bits.  
Address:  
$1024  
Bit 7  
6
RTI  
0
5
PAOVI  
0
4
PAII  
0
3
0
2
0
1
PR1  
0
Bit 0  
PR0  
0
Read:  
Write:  
Reset:  
TOI  
0
= Unimplemented  
Figure 9-21. Timer Interrupt Mask 2 Register (TMSK2)  
TOI — Timer Overflow Interrupt Enable Bit  
0 = TOF interrupts disabled  
1 = Interrupt requested when TOF is set to 1  
RTII — Real-Time Interrupt Enable Bit  
0 = RTIF interrupts disabled  
1 = Interrupt requested when RTIF set to 1  
PAOVI — Pulse Accumulator Overflow Interrupt Enable Bit  
Refer to 9.7 Pulse Accumulator.  
PAII — Pulse Accumulator Input Edge Bit  
Refer to 9.7 Pulse Accumulator.  
Bits [3:2] — Unimplemented  
Always read 0  
PR[1:0] — Timer Prescaler Select Bits  
Refer to Table 9-4.  
NOTE  
Bits in TMSK2 correspond bit for bit with flag bits in TFLG2. Bits in TMSK2  
enable the corresponding interrupt sources.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
141  
Timing Systems  
9.5.2 Timer Interrupt Flag Register 2  
Bits of this register indicate the occurrence of timer system events. Coupled with the four high-order bits  
of TMSK2, the bits of TFLG2 allow the timer subsystem to operate in either a polled or interrupt driven  
system. Each bit of TFLG2 corresponds to a bit in TMSK2 in the same position.  
Address:  
$1025  
Bit 7  
6
RTIF  
0
5
PAOVF  
0
4
PAIF  
0
3
0
2
0
1
0
Bit 0  
Read:  
Write:  
Reset:  
TOF  
0
0
= Unimplemented  
Figure 9-22. Timer Interrupt Flag 2 Register (TFLG2)  
Clear flags by writing a 1 to the corresponding bit position(s).  
TOF — Timer Overflow Interrupt Flag  
Set when TCNT changes from $FFFF to $0000  
RTIF — Real-Time Interrupt Flag  
The RTIF status bit is automatically set to 1 at the end of every RTI period. To clear RTIF, write a byte  
to TFLG2 with bit 6 set.  
PAOVF — Pulse Accumulator Overflow Interrupt Flag  
Refer to 9.7 Pulse Accumulator.  
PAIF — Pulse Accumulator Input Edge Interrupt Flag  
Refer to 9.7 Pulse Accumulator.  
Bits [3:0] — Unimplemented  
Always read 0  
9.5.3 Pulse Accumulator Control Register  
Bits RTR[1:0] of this register select the rate for the RTI system. The remaining bits control the pulse  
accumulator and IC4/OC5 functions.  
Address:  
$1026  
Bit 7  
6
PAEN  
0
5
PAMOD  
0
4
PEDGE  
0
3
DDRA3  
0
2
I4/O5  
0
1
RTR1  
0
Bit 0  
RTR0  
0
Read:  
Write:  
Reset:  
DDRA7  
0
Figure 9-23. Pulse Accumulator Control Register (PACTL)  
DDRA7 — Data Direction for Port A Bit 7  
Refer to Chapter 6 Parallel Input/Output (I/O) Ports.  
PAEN — Pulse Accumulator System Enable Bit  
Refer to 9.7 Pulse Accumulator.  
PAMOD — Pulse Accumulator Mode Bit  
Refer to 9.7 Pulse Accumulator.  
M68HC11E Family Data Sheet, Rev. 5.1  
142  
Freescale Semiconductor  
Computer Operating Properly (COP) Watchdog Function  
PEDGE — Pulse Accumulator Edge Control Bit  
Refer to 9.7 Pulse Accumulator.  
DDRA3 — Data Direction for Port A Bit 3  
Refer to Chapter 6 Parallel Input/Output (I/O) Ports.  
I4/O5 — Input Capture 4/Output Compare Bit  
Refer to 9.7 Pulse Accumulator.  
RTR[1:0] — RTI Interrupt Rate Select Bits  
These two bits determine the rate at which the RTI system requests interrupts. The RTI system is  
driven by an E divided by 213 rate clock that is compensated so it is independent of the timer prescaler.  
These two control bits select an additional division factor. Refer to Table 9-5.  
9.6 Computer Operating Properly (COP) Watchdog Function  
The clocking chain for the COP function, tapped off of the main timer divider chain, is only superficially  
related to the main timer system. The CR[1:0] bits in the OPTION register and the NOCOP bit in the  
CONFIG register determine the status of the COP function. One additional register, COPRST, is used to  
arm and clear the COP watchdog reset system. Refer to Chapter 5 Resets and Interrupts for a more  
detailed discussion of the COP function.  
9.7 Pulse Accumulator  
The M68HC11 Family of MCUs has an 8-bit counter that can be configured to operate either as a simple  
event counter or for gated time accumulation, depending on the state of the PAMOD bit in the PACTL  
register. Refer to the pulse accumulator block diagram, Figure 9-24. In the event counting mode, the 8-bit  
counter is clocked to increasing values by an external pin. The maximum clocking rate for the external  
event counting mode is the E clock divided by two. In gated time accumulation mode, a free-running  
E-clock divide-by-64 signal drives the 8-bit counter, but only while the external PAI pin is activated. Refer  
to Table 9-6. The pulse accumulator counter can be read or written at any time.  
Table 9-6. Pulse Accumulator Timing  
Crystal  
Frequency  
PACNT  
Overflow  
E Clock  
Cycle Time  
E ÷ 64  
4.0 MHz  
8.0 MHz  
12.0 MHz  
1 MHz  
2 MHz  
3 MHz  
1000 ns  
500 ns  
333 ns  
64 µs  
32 µs  
16.384 ms  
8.192 ms  
5.461 ms  
21.33 µs  
Pulse accumulator control bits are also located within two timer registers, TMSK2 and TFLG2, as  
described in the following paragraphs.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
143  
Timing Systems  
PAOVI  
PAOVF  
1
INTERRUPT  
REQUESTS  
PAII  
PAIF  
2
E ÷ 64 CLOCK  
FROM MAIN TIMER  
TMSK2 INT ENABLES  
TFLG2 INTERRUPT STATUS  
PAI EDGE  
PAEN  
DISABLE  
FLAG SETTING  
OVERFLOW  
MCU PIN  
CLOCK  
PAEN  
2 1  
:
MUX  
PA7/  
PAI/  
OC1  
INPUT BUFFER  
AND  
EDGE DETECTOR  
PACNT 8-BIT COUNTER  
ENABLE  
DATA  
BUS  
OUTPUT  
BUFFER  
FROM  
MAIN TIMER  
OC1  
FROM  
DDRA7  
PACTL CONTROL  
INTERNAL  
DATA BUS  
Figure 9-24. Pulse Accumulator  
M68HC11E Family Data Sheet, Rev. 5.1  
144  
Freescale Semiconductor  
Pulse Accumulator  
9.7.1 Pulse Accumulator Control Register  
Four of this register’s bits control an 8-bit pulse accumulator system. Another bit enables either the OC5  
function or the IC4 function, while two other bits select the rate for the real-time interrupt system.  
Address:  
$1026  
Bit 7  
6
PAEN  
0
5
PAMOD  
0
4
PEDGE  
0
3
DDRA3  
0
2
I4/O5  
0
1
RTR1  
0
Bit 0  
RTR0  
0
Read:  
Write:  
Reset:  
DDRA7  
0
Figure 9-25. Pulse Accumulator Control Register (PACTL)  
DDRA7 — Data Direction for Port A Bit 7  
Refer to Chapter 6 Parallel Input/Output (I/O) Ports.  
PAEN — Pulse Accumulator System Enable Bit  
0 = Pulse accumulator disabled  
1 = Pulse accumulator enabled  
PAMOD — Pulse Accumulator Mode Bit  
0 = Event counter  
1 = Gated time accumulation  
PEDGE — Pulse Accumulator Edge Control Bit  
This bit has different meanings depending on the state of the PAMOD bit, as shown in Table 9-7.  
Table 9-7. Pulse Accumulator Edge Control  
PAMOD  
PEDGE  
Action on Clock  
PAI falling edge increments the counter.  
PAI rising edge increments the counter.  
A 0 on PAI inhibits counting.  
0
0
1
1
0
1
0
1
A 1 on PAI inhibits counting.  
DDRA3 — Data Direction for Port A Bit 3  
Refer to Chapter 6 Parallel Input/Output (I/O) Ports.  
I4/O5 — Input Capture 4/Output Compare 5 Bit  
0 = Output compare 5 function enable (no IC4)  
1 = Input capture 4 function enable (no OC5)  
RTR[1:0] — RTI Interrupt Rate Select Bits  
Refer to 9.5 Real-Time Interrupt (RTI).  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
145  
Timing Systems  
9.7.2 Pulse Accumulator Count Register  
This 8-bit read/write register contains the count of external input events at the PAI input or the  
accumulated count. The PACNT is readable even if PAI is not active in gated time accumulation mode.  
The counter is not affected by reset and can be read or written at any time. Counting is synchronized to  
the internal PH2 clock so that incrementing and reading occur during opposite half cycles.  
Address:  
$1027  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
Reset:  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
Indeterminate after reset  
Figure 9-26. Pulse Accumulator Count Register (PACNT)  
9.7.3 Pulse Accumulator Status and Interrupt Bits  
The pulse accumulator control bits, PAOVI and PAII, PAOVF and PAIF, are located within timer registers  
TMSK2 and TFLG2.  
Address:  
$1024  
Bit 7  
6
RTII  
0
5
PAOVI  
0
4
PAII  
0
3
0
2
0
1
PR1  
0
Bit 0  
PR0  
0
Read:  
Write:  
Reset:  
TOI  
0
= Unimplemented  
Figure 9-27. Timer Interrupt Mask 2 Register (TMSK2)  
Address:  
$1025  
Bit 7  
TOF  
0
6
RTIF  
0
5
PAOVF  
0
4
PAIF  
0
3
0
2
0
1
0
Bit 0  
Read:  
Write:  
Reset:  
0
= Unimplemented  
Figure 9-28. Timer Interrupt Flag 2 Register (TFLG2)  
PAOVI and PAOVF — Pulse Accumulator Interrupt Enable and Overflow Flag  
The PAOVF status bit is set each time the pulse accumulator count rolls over from $FF to $00. To clear  
this status bit, write a 1 in the corresponding data bit position (bit 5) of the TFLG2 register. The PAOVI  
control bit allows configuring the pulse accumulator overflow for polled or interrupt-driven operation  
and does not affect the state of PAOVF. When PAOVI is 0, pulse accumulator overflow interrupts are  
inhibited, and the system operates in a polled mode, which requires that PAOVF be polled by user  
software to determine when an overflow has occurred. When the PAOVI control bit is set, a hardware  
interrupt request is generated each time PAOVF is set. Before leaving the interrupt service routine,  
software must clear PAOVF by writing to the TFLG2 register.  
M68HC11E Family Data Sheet, Rev. 5.1  
146  
Freescale Semiconductor  
Pulse Accumulator  
PAII and PAIF — Pulse Accumulator Input Edge Interrupt Enable Bit and Flag  
The PAIF status bit is automatically set each time a selected edge is detected at the PA7/PAI/OC1 pin.  
To clear this status bit, write to the TFLG2 register with a 1 in the corresponding data bit position (bit  
4). The PAII control bit allows configuring the pulse accumulator input edge detect for polled or  
interrupt-driven operation but does not affect setting or clearing the PAIF bit. When PAII is 0, pulse  
accumulator input interrupts are inhibited, and the system operates in a polled mode. In this mode, the  
PAIF bit must be polled by user software to determine when an edge has occurred. When the PAII  
control bit is set, a hardware interrupt request is generated each time PAIF is set. Before leaving the  
interrupt service routine, software must clear PAIF by writing to the TFLG2 register.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
147  
Timing Systems  
M68HC11E Family Data Sheet, Rev. 5.1  
148  
Freescale Semiconductor  
Chapter 10  
Electrical Characteristics  
10.1 Introduction  
This section contains electrical specifications for the M68HC11 E-series devices.  
10.2 Maximum Ratings for Standard and Extended Voltage Devices  
Maximum ratings are the extreme limits to which the microcontroller unit (MCU) can be exposed without  
permanently damaging it.  
NOTE  
This device is not guaranteed to operate properly at the maximum ratings.  
Refer to 10.5 DC Electrical Characteristics, 10.6 Supply Currents and  
Power Dissipation, 10.7 MC68L11E9/E20 DC Electrical Characteristics,  
and 10.8 MC68L11E9/E20 Supply Currents and Power Dissipation for  
guaranteed operating conditions.  
Rating  
Symbol  
Value  
Unit  
V
VDD  
Supply voltage  
Input voltage  
–0.3 to +7.0  
–0.3 to +7.0  
VIn  
V
Current drain per pin(1) excluding VDD, VSS, AVDD, VRH, VRL, and  
XIRQ/VPPE  
ID  
25  
mA  
TSTG  
Storage temperature  
–55 to +150  
°C  
1. One pin at a time, observing maximum power dissipation limits  
NOTE  
This device contains circuitry to protect the inputs against damage due to  
high static voltages or electric fields; however, it is advised that normal  
precautions be taken to avoid application of any voltage higher than  
maximum-rated voltages to this high-impedance circuit. For proper  
operation, it is recommended that VIn and VOut be constrained to the range  
VSS (VIn or VOut) VDD. Reliability of operation is enhanced if unused  
inputs are connected to an appropriate logic voltage level (for example,  
either VSS or VDD).  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
149  
Electrical Characteristics  
10.3 Functional Operating Range  
Rating  
Symbol  
Value  
Unit  
°C  
TL to TH  
Operating temperature range  
MC68HC(7)11Ex  
MC68HC(7)11ExC  
MC68HC(7)11ExV  
MC68HC(7)11ExM  
MC68HC811E2  
0 to +70  
–40 to +85  
–40 to +105  
–40 to +125  
0 to +70  
TA  
MC68HC811E2C  
MC68HC811E2V  
MC68HC811E2M  
MC68L11Ex  
–40 to +85  
–40 to +105  
–40 to +125  
–20 to +70  
VDD  
Operating voltage range  
5.0 10%  
V
10.4 Thermal Characteristics  
Characteristic  
Average junction temperature  
Ambient temperature  
Symbol  
Value  
Unit  
°C  
TJ  
TA + (PD × ΘJA)  
TA  
User-determined  
°C  
Package thermal resistance (junction-to-ambient)  
48-pin plastic DIP (MC68HC811E2 only)  
56-pin plastic SDIP  
50  
50  
50  
85  
85  
ΘJA  
°C/W  
52-pin plastic leaded chip carrier  
52-pin plastic thin quad flat pack (TQFP)  
64-pin quad flat pack  
PINT + PI/O  
K / TJ + 273°C  
Total power dissipation(1)  
PD  
W
PINT  
PI/O  
IDD × VDD  
Device internal power dissipation  
I/O pin power dissipation(2)  
W
W
User-determined  
PD × (TA + 273°C)  
A constant(3)  
K
W/°C  
2
+ ΘJA × PD  
1. This is an approximate value, neglecting PI/O  
.
2. For most applications, PI/O PINT and can be neglected.  
3. K is a constant pertaining to the device. Solve for K with a known TA and a measured PD (at equilibrium). Use this value  
of K to solve for PD and TJ iteratively for any value of TA.  
M68HC11E Family Data Sheet, Rev. 5.1  
150  
Freescale Semiconductor  
DC Electrical Characteristics  
10.5 DC Electrical Characteristics  
Characteristics(1)  
Symbol  
Min  
Max  
Unit  
Output voltage(2)  
ILoad  
=
10.0 µA  
VOL, VOH  
V
0.1  
All outputs except XTAL  
All outputs except XTAL, RESET, and MODA  
VDD –0.1  
Output high voltage(2)  
VOH  
VDD –0.8  
V
V
ILoad = –0.8 mA, VDD = 4.5 V  
All outputs except XTAL, RESET, and MODA  
Output low voltage  
ILoad = 1.6 mA  
VOL  
0.4  
All outputs except XTAL  
Input high voltage  
All inputs except RESET  
RESET  
0.7 × V  
VDD + 0.3  
VDD + 0.3  
DD  
VIH  
VIL  
V
V
0.8 × V  
DD  
VSS –0.3  
0.2 × VDD  
Input low voltage, all inputs  
I/O ports, 3-state leakage  
VIn = VIH or VIL  
IOZ  
10  
µA  
µA  
PA7, PA3, PC[7:0], PD[5:0], AS/STRA,  
MODA/LIR, RESET  
Input leakage current(3)  
VIn = VDD or VSS  
IIn  
1
10  
PA[2:0], IRQ, XIRQ  
MODB/VSTBY (XIRQ on EPROM-based devices)  
VSB  
ISB  
VDD  
10  
RAM standby voltage, power down  
RAM standby current, power down  
4.0  
V
µA  
Input capacitance  
CIn  
CL  
PA[2:0], PE[7:0], IRQ, XIRQ, EXTAL  
PA7, PA3, PC[7:0], PD[5:0], AS/STRA, MODA/LIR, RESET  
8
12  
pF  
pF  
Output load capacitance  
All outputs except PD[4:1]  
PD[4:1]  
90  
100  
1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted  
2. VOH specification for RESET and MODA is not applicable because they are open-drain pins. VOH specification not appli-  
cable to ports C and D in wired-OR mode.  
3. Refer to 10.13 Analog-to-Digital Converter Characteristics and 10.14 MC68L11E9/E20 Analog-to-Digital Converter Char-  
acteristics for leakage current for port E.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
151  
Electrical Characteristics  
10.6 Supply Currents and Power Dissipation  
Characteristics(1)  
Run maximum total supply current(2)  
Symbol  
Min  
Max  
Unit  
15  
27  
27  
35  
Single-chip mode2 MHz  
IDD  
mA  
3 MHz  
Expanded multiplexed mode2 MHz  
3 MHz  
Wait maximum total supply current(2)  
(all peripheral functions shut down)  
Single-chip mode2 MHz  
3 MHz  
6
WIDD  
15  
10  
20  
mA  
Expanded multiplexed mode2 MHz  
3 MHz  
Stop maximum total supply current(2)  
Single-chip mode, no clocks–40°C to +85°C  
> +85°C to +105°C  
25  
50  
100  
SIDD  
µA  
> +105°C to +125°C  
Maximum power dissipation  
Single-chip mode2 MHz  
3 MHz  
85  
PD  
150  
150  
195  
mW  
Expanded multiplexed mode2 MHz  
3 MHz  
1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted  
2. EXTAL is driven with a square wave, and  
tCYC= 500 ns for 2 MHz rating  
t
CYC= 333 ns for 3 MHz rating  
VIL 0.2 V  
VIH VDD – 0.2 V  
no dc loads  
M68HC11E Family Data Sheet, Rev. 5.1  
152  
Freescale Semiconductor  
MC68L11E9/E20 DC Electrical Characteristics  
10.7 MC68L11E9/E20 DC Electrical Characteristics  
Characteristics(1)  
Symbol  
Min  
Max  
Unit  
Output voltage(2)  
ILoad 10.0 µA  
=
V
OL, VOH  
DD –0.1  
0.1  
V
All outputs except XTAL  
All outputs except XTAL, RESET, and MODA  
V
Output high voltage(2)  
ILoad = –0.5 mA, VDD = 3.0 V  
ILoad = –0.8 mA, VDD = 4.5 V  
All outputs except XTAL, RESET, and MODA  
VOH  
VDD –0.8  
V
V
Output low voltage  
ILoad = 1.6 mA, VDD = 5.0 V  
VOL  
0.4  
ILoad = 1.0 mA, VDD = 3.0 V  
All outputs except XTAL  
Input high voltage  
All inputs except RESET  
RESET  
VDD + 0.3  
VDD + 0.3  
0.7 × V  
VIH  
VIL  
V
V
DD  
0.8 × V  
DD  
VSS –0.3  
0.2 × VDD  
Input low voltage, all inputs  
I/O ports, 3-state leakage  
VIn = VIH or VIL  
IOZ  
10  
µA  
µA  
PA7, PA3, PC[7:0], PD[5:0], AS/STRA,  
MODA/LIR, RESET  
Input leakage current(3)  
VIn = VDD or VSS  
IIn  
1
10  
PA[2:0], IRQ, XIRQ  
MODB/VSTBY (XIRQ on EPROM-based devices)  
VSB  
ISB  
VDD  
10  
RAM standby voltage, power down  
RAM standby current, power down  
2.0  
V
µA  
Input capacitance  
PA[2:0], PE[7:0], IRQ, XIRQ, EXTAL  
PA7, PA3, PC[7:0], PD[5:0], AS/STRA, MODA/LIR, RESET  
l
8
12  
pF  
pF  
Output load capacitance  
All outputs except PD[4:1]  
PD[4:1]  
CL  
90  
100  
1. VDD = 3.0 Vdc to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted  
2. VOH specification for RESET and MODA is not applicable because they are open-drain pins. VOH specification not appli-  
cable to ports C and D in wired-OR mode.  
3. Refer to 10.13 Analog-to-Digital Converter Characteristics and 10.14 MC68L11E9/E20 Analog-to-Digital Converter Char-  
acteristics for leakage current for port E.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
153  
Electrical Characteristics  
10.8 MC68L11E9/E20 Supply Currents and Power Dissipation  
Characteristic(1)  
Run maximum total supply current(2)  
Symbol  
1 MHz  
2 MHz  
Unit  
Single-chip mode  
VDD = 5.5 V  
8
4
15  
8
IDD  
VDD = 3.0 V  
mA  
Expanded multiplexed mode  
VDD = 5.5 V  
14  
7
27  
14  
VDD = 5.5 V  
Wait maximum total supply current(2)  
(all peripheral functions shut down)  
Single-chip mode  
V
DD = 5.5 V  
3
1.5  
6
3
WIDD  
mA  
VDD = 3.0 V  
Expanded multiplexed mode  
VDD = 5.5 V  
5
2.5  
10  
5
VDD = 3.0 V  
Stop maximum total supply current(2)  
Single-chip mode, no clocks  
VDD = 5.5 V  
SIDD  
µA  
50  
25  
50  
25  
VDD = 3.0 V  
Maximum power dissipation  
Single-chip mode  
2 MHz  
3 MHz  
44  
12  
85  
24  
PD  
mW  
Expanded multiplexed mode  
2 MHz  
3 MHz  
77  
21  
150  
42  
1. VDD = 3.0 Vdc to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted  
2. EXTAL is driven with a square wave, and  
tCYC= 500 ns for 2 MHz rating  
t
CYC= 333 ns for 3 MHz rating  
VIL 0.2 V  
VIH VDD – 0.2 V  
no dc loads  
M68HC11E Family Data Sheet, Rev. 5.1  
154  
Freescale Semiconductor  
MC68L11E9/E20 Supply Currents and Power Dissipation  
V
~ DD  
CLOCKS,  
STROBES  
V
– 0.8 VOLTS  
NOM  
DD  
0.4 VOLTS  
0.4 VOLTS  
NOM  
~V  
SS  
70% of V  
20% of V  
DD  
INPUTS  
DD  
NOMINAL TIMING  
V
~
DD  
V
– 0.8 Volts  
DD  
OUTPUTS  
0.4 Volts  
~V  
SS  
DC TESTING  
~V  
DD  
70% of V  
SPEC  
CLOCKS,  
STROBES  
DD  
20% of V  
20% of V  
SPEC  
DD  
DD  
V
~ SS  
(NOTE 2)  
V
– 0.8 VOLTS  
DD  
70% of V  
DD  
INPUTS  
20% of V  
DD  
0.4 VOLTS  
SPEC TIMING  
V
~ DD  
70% of V  
20% of V  
DD  
DD  
OUTPUTS  
V
~ SS  
AC TESTING  
Notes:  
1. Full test loads are applied during all dc electrical tests and ac timing measurements.  
2. During ac timing measurements, inputs are driven to 0.4 volts and VDD – 0.8 volts while timing  
measurements are taken at 20% and 70% of VDD points.  
Figure 10-1. Test Methods  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
155  
Electrical Characteristics  
10.9 Control Timing  
1.0 MHz  
2.0 MHz  
3.0 MHz  
Characteristic(1) (2)  
Symbol  
fo  
Unit  
Min Max Min Max Min Max  
Frequency of operation  
E-clock period  
dc  
1.0  
dc  
2.0  
dc  
3.0  
MHz  
ns  
100  
0
tCYC  
500  
333  
fXTAL  
4 fo  
Crystal frequency  
dc  
4.0  
4.0  
dc  
8.0  
8.0  
dc  
12.0  
12.0  
MHz  
MHz  
External oscillator frequency  
Processor control setup time  
tPCSU = 1/4 tCYC+ 50 ns  
tPCSU  
300  
175  
133  
ns  
Reset input pulse width  
PWRSTL  
tCYC  
To guarantee external reset vector  
Minimum input time (can be pre-empted by internal reset)  
8
1
8
1
8
1
tMPS  
tMPH  
tCYC  
ns  
Mode programming setup time  
Mode programming hold time  
2
2
2
10  
10  
10  
Interrupt pulse width, IRQ edge-sensitive mode  
PWIRQ = tCYC + 20 ns  
102  
0
PWIRQ  
tWRS  
4
520  
4
353  
4
ns  
tCYC  
Wait recovery startup time  
Timer pulse width input capture pulse accumulator input  
PWTIM = tCYC + 20 ns  
102  
0
PWTIM  
520  
353  
ns  
1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH, all timing is shown with respect to 20% VDD and 70% VDD, unless oth-  
erwise noted  
2. RESET is recognized during the first clock cycle it is held low. Internal circuitry then drives the pin low for four clock cycles,  
releases the pin, and samples the pin level two cycles later to determine the source of the interrupt. Refer to Chapter 5  
Resets and Interrupts for further detail.  
M68HC11E Family Data Sheet, Rev. 5.1  
156  
Freescale Semiconductor  
MC68L11E9/E20 Control Timing  
10.10 MC68L11E9/E20 Control Timing  
1.0 MHz  
2.0 MHz  
Characteristic(1) (2)  
Symbol  
Unit  
Min  
dc  
Max  
1.0  
Min  
Max  
2.0  
fo  
Frequency of operation  
E-clock period  
dc  
500  
MHz  
ns  
tCYC  
fXTAL  
4 fo  
1000  
Crystal frequency  
4.0  
4.0  
8.0  
8.0  
MHz  
MHz  
External oscillator frequency  
dc  
dc  
Processor control setup time  
tPCSU = 1/4 tCYC+ 75 ns  
tPCSU  
325  
200  
ns  
Reset input pulse width  
PWRSTL  
tCYC  
To guarantee external reset vector  
Minimum input time (can be pre-empted by internal reset)  
8
1
8
1
tMPS  
tMPH  
tCYC  
ns  
Mode programming setup time  
Mode programming hold time  
2
2
10  
10  
Interrupt pulse width, IRQ edge-sensitive mode  
PWIRQ = tCYC + 20 ns  
PWIRQ  
tWRS  
1020  
4
520  
4
ns  
tCYC  
Wait recovery startup time  
Timer pulse width input capture pulse accumulator input  
PWTIM = tCYC + 20 ns  
PWTIM  
1020  
520  
ns  
1. VDD = 3.0 Vdc to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH, all timing is shown with respect to 20% VDD and 70% VDD, unless  
otherwise noted  
2. RESET is recognized during the first clock cycle it is held low. Internal circuitry then drives the pin low for four clock cycles,  
releases the pin, and samples the pin level two cycles later to determine the source of the interrupt. Refer to Chapter 5  
Resets and Interrupts for further detail.  
(1)  
PA[2:0]  
(2)  
PA[2:0]  
(1) (3)  
PA7  
PW  
TIM  
(2) (3)  
PA7  
Notes:  
1. Rising edge sensitive input  
2. Falling edge sensitive input  
3. Maximum pulse accumulator clocking rate is E-clock frequency divided by 2.  
Figure 10-2. Timer Inputs  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
157  
VDD  
EXTAL  
4064 tCYC  
E
tPCSU  
PWRSTL  
RESET  
tMPS  
tMPH  
MODA, MODB  
ADDRESS  
NEW  
PC  
NEW  
PC  
FFFE  
FFFE  
FFFE  
FFFE  
FFFF  
FFFE  
FFFE  
FFFE  
FFFE  
FFFE  
FFFF  
Figure 10-3. POR External Reset Timing Diagram  
INTERNAL  
CLOCKS  
IRQ1  
PWIRQ  
IRQ  
or XIRQ  
3
tSTOPDELAY  
E
STOP  
ADDR + 1  
STOP  
ADDR  
STOP  
ADDR + 1  
ADDRESS4  
OPCODE  
Resume program with instruction which follows the STOP instruction.  
STOP  
ADDR + 2  
FFF2  
(FFF4)  
FFF3  
(FFF5)  
STOP  
ADDR + 1  
STOP  
ADDR  
STOP  
ADDR + 1  
NEW  
PC  
ADDRESS5  
SP…SP–7  
SP – 8  
SP – 8  
Notes:  
1. Edge Sensitive IRQ pin (IRQE bit = 1)  
2. Level sensitive IRQ pin (IRQE bit = 0)  
3. tSTOPDELAY = 4064 tCYC if DLY bit = 1 or 4 tCYC if DLY = 0.  
4. XIRQ with X bit in CCR = 1.  
5. IRQ or (XIRQ with X bit in CCR = 0).  
Figure 10-4. STOP Recovery Timing Diagram  
E
tPCSU  
IRQ, XIRQ,  
OR INTERNAL  
INTERRUPTS  
tWRS  
NEW  
PC  
WAIT  
ADDR  
WAIT  
ADDR + 1  
VECTOR  
ADDR  
VECTOR  
ADDR + 1  
SP  
SP – 1  
SP – 8  
SP – 8  
SP – 8  
SP – 8  
SP – 2…SP – 8  
SP – 8…SP – 8  
ADDRESS  
PCL  
PCH, YL, YH, XL, XH, A, B, CCR  
STACK REGISTERS  
R/W  
Note: RESET also causes recovery from WAIT.  
Figure 10-5. WAIT Recovery from Interrupt Timing Diagram  
E
tPCSU  
IRQ 1  
PWIRQ  
IRQ 2, XIRQ,  
OR INTERNAL  
INTERRUPT  
NEXT  
OPCODE  
NEXT  
OP + 1  
VECTOR  
ADDR  
VECTOR  
ADDR + 1  
NEW  
PC  
ADDRESS  
SP  
SP – 1  
PCH  
SP – 2  
SP – 3  
SP – 4  
SP – 5  
SP – 6  
SP – 7  
SP – 8  
CCR  
SP – 8  
OP  
CODE  
VECT  
MSB  
VECT  
LSB  
OP  
CODE  
– –  
PCL  
IYL  
IYH  
IXL  
IXH  
B
A
– –  
DATA  
R/W  
Notes:  
1. Edge sensitive IRQ pin (IRQE bit = 1)  
2. Level sensitive IRQ pin (IRQE bit = 0)  
Figure 10-6. Interrupt Timing Diagram  
Electrical Characteristics  
10.11 Peripheral Port Timing  
1.0 MHz  
2.0 MHz  
3.0 MHz  
Characteristic(1) (2)  
Symbol  
Unit  
Min  
Max  
1.0  
Min  
Max  
2.0  
Min  
Max  
3.0  
Frequency of operation  
E-clock frequency  
fo  
dc  
dc  
dc  
MHz  
ns  
tCYC  
tPDSU  
tPDH  
E-clock period  
1000  
100  
500  
100  
333  
100  
Peripheral data setup time  
ns  
MCU read of ports A, C, D, and E  
Peripheral data hold time  
50  
50  
50  
ns  
ns  
MCU read of ports A, C, D, and E  
Delay time, peripheral data write  
tPWD = 1/4 tCYC+ 100 ns  
tPWD  
200  
350  
200  
225  
200  
183  
MCU writes to port A  
MCU writes to ports B, C, and D  
tIS  
tIH  
Port C input data setup time  
Port C input data hold time  
60  
60  
60  
ns  
ns  
100  
100  
100  
Delay time, E fall to STRB  
tDEB = 1/4 tCYC+ 100 ns  
tDEB  
350  
225  
183  
ns  
Setup time, STRA asserted to E fall(3)  
Delay time, STRA asserted to port C data output valid  
Hold time, STRA negated to port C data  
3-state hold time  
tAES  
tPCD  
tPCH  
tPCZ  
0
100  
0
100  
0
100  
ns  
ns  
ns  
ns  
10  
10  
10  
150  
150  
150  
1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH, all timing is shown with respect to 20% VDD and 70% VDD, unless  
otherwise noted  
2. Ports C and D timing is valid for active drive. (CWOM and DWOM bits are not set in PIOC and SPCR registers, respec-  
tively.)  
3. If this setup time is met, STRB acknowledges in the next cycle. If it is not met, the response may be delayed one more cycle.  
M68HC11E Family Data Sheet, Rev. 5.1  
162  
Freescale Semiconductor  
MC68L11E9/E20 Peripheral Port Timing  
10.12 MC68L11E9/E20 Peripheral Port Timing  
1.0 MHz  
2.0 MHz  
Characteristic(1) (2)  
Symbol  
Unit  
Min  
Max  
1.0  
Min  
Max  
2.0  
Frequency of operation  
fo  
dc  
dc  
MHz  
ns  
E-clock frequency  
tCYC  
E-clock period  
1000  
100  
500  
100  
Peripheral data setup time  
tPDSU  
ns  
MCU read of ports A, C, D, and E  
Peripheral data hold time  
tPDH  
50  
50  
ns  
ns  
MCU read of ports A, C, D, and E  
Delay time, peripheral data write  
tPWD = 1/4 tCYC+ 150 ns  
tPWD  
250  
400  
250  
275  
MCU writes to port A  
MCU writes to ports B, C, and D  
tIS  
tIH  
Port C input data setup time  
Port C input data hold time  
60  
60  
ns  
ns  
100  
100  
Delay time, E fall to STRB  
tDEB = 1/4 tCYC+ 150 ns  
tDEB  
400  
275  
ns  
Setup time, STRA asserted to E fall(3)  
Delay time, STRA asserted to port C data output valid  
Hold time, STRA negated to port C data  
3-state hold time  
tAES  
tPCD  
tPCH  
tPCZ  
0
100  
0
100  
ns  
ns  
ns  
ns  
10  
10  
150  
150  
1. VDD = 3.0 Vdc to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH, all timing is shown with respect to 20% VDD and 70% VDD, unless  
otherwise noted  
2. Ports C and D timing is valid for active drive. (CWOM and DWOM bits are not set in PIOC and SPCR registers, respec-  
tively.)  
3. If this setup time is met, STRB acknowledges in the next cycle. If it is not met, the response may be delayed one more cycle.  
Figure 10-7. Port Read Timing Diagram  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
163  
Electrical Characteristics  
Figure 10-8. Port Write Timing Diagram  
Figure 10-9. Simple Input Strobe Timing Diagram  
MCU WRITE TO PORT B  
E
t
t
PWD  
NEW DATA VALID  
PORT B  
PREVIOUS PORT DATA  
tDE  
B
STRB (OUT)  
Figure 10-10. Simple Output Strobe Timing Diagram  
(1)  
READPORTCL  
E
tDEB
tDEB
“READY”  
STRB (0UT)  
t
AES  
STRA (IN)  
tIS
tIH  
PORT C (IN)  
Notes:  
1. After reading PIOC with STAF set  
2. Figure shows rising edge STRA (EGA = 1) and high true STRB (INVB = 1).  
Figure 10-11. Port C Input Handshake Timing Diagram  
M68HC11E Family Data Sheet, Rev. 5.1  
164  
Freescale Semiconductor  
MC68L11E9/E20 Peripheral Port Timing  
(1)  
WRITE PORTCL  
E
t
t
PWD  
PORT C (OUT)  
PREVIOUS PORT DATA  
NEW DATA VALID  
t
DEB  
t
DEB  
“READY”  
STRB (IN)  
t
AES  
STRA (IN)  
Notes:  
1. After reading PIOC with STAF set  
2. Figure shows rising edge STRA (EGA = 1) and high true STRB (INVB = 1).  
Figure 10-12. Port C Output Handshake Timing Diagram  
(1)  
READ PORTCL  
E
t
PWD  
PORT C (OUT)  
DDR = 1  
tDEB
t
DEB
“READY”  
STRB (OUT)  
t
E  
A S
STRA (IN)  
t
PCD  
t
PCH  
PORT C (OUT)  
OLD DATA  
D  
NEW DATA VALID  
DDR = 0  
t
P  
CZ  
a) STRA ACTIVE BEFORE PORTCL WRITE  
STRA (IN)  
t
t
t
PCD  
PCH  
PORT C (OUT)  
NEW DATA VALID  
DDR = 0  
tPCZ
b) STRA ACTIVE AFTER PORTCL WRITE  
Notes:  
1. After reading PIOC with STAF set  
2. Figure shows rising edge STRA (EGA = 1) and high true STRB (INVB = 1).  
Figure 10-13. 3-State Variation of Output Handshake Timing Diagram  
(STRA Enables Output Buffer)  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
165  
Electrical Characteristics  
10.13 Analog-to-Digital Converter Characteristics  
2.0 MHz 3.0 MHz  
Uni  
t
Characteristic(1)  
Resolution  
Parameter(2)  
Min  
Absolute  
Max  
Max  
Number of bits resolved by A/D converter  
8
Bits  
Maximum deviation from the ideal A/D transfer  
characteristics  
LS  
B
Non-linearity  
1/2  
1/2  
1/2  
1/2  
1/2  
1
1
Difference between the output of an ideal and an  
actual for 0 input voltage  
LS  
B
Zero error  
Difference between the output of an ideal and an  
actual A/D for full-scale input voltage  
LS  
B
Full scale error  
1
Total unadjusted  
error  
Maximum sum of non-linearity, zero error, and  
full-scale error  
LS  
B
1/2  
1/2  
Quantization  
error  
LS  
B
Uncertainty because of converter resolution  
Difference between the actual input voltage and  
the full-scale weighted equivalent of the binary  
output code, all error sources included  
Absolute  
accuracy  
LS  
B
1
2
Conversion  
range  
VRL  
VRH  
VRH  
Analog input voltage range  
V
Maximum analog reference voltage(3)  
Minimum analog reference voltage(2)  
VRH  
VRL  
VR  
VRL  
VDD +0.1 VDD +0.1  
V
V
V
V
SS –0.1  
VRH  
VRH  
(2)  
3
Minimum difference between VRH and VRL  
Total time to perform a single A/D conversion:  
E clock  
Conversion  
time  
tCY  
C
µs  
32  
tCYC+32 tCYC+32  
Internal RC oscillator  
Conversion result never decreases with an  
Monotonicity  
00  
Guaranteed  
increase in input voltage; has no missing codes  
Conversion result when VIn = VRL  
Zero input reading  
Hex  
Hex  
Full scale  
reading  
Conversion result when VIn = VRH  
FF  
FF  
Sample  
acquisition  
time  
Analog input acquisition sampling time:  
E clock  
tCY  
C
µs  
12  
12  
12  
Internal RC oscillator  
Sample/hold  
capacitance  
Input capacitance during sample  
PE[7:0]  
20 typical  
pF  
Input leakage on A/D pins  
PE[7:0]  
Input leakage  
400  
1.0  
400  
1.0  
nA  
µA  
VRL, VRH  
1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH, 750 kHz E 3.0 MHz, unless otherwise noted  
2. Source impedances greater than 10 kaffect accuracy adversely because of input leakage.  
3. Performance verified down to 2.5 V VR, but accuracy is tested and guaranteed at VR = 5 V 10%.  
M68HC11E Family Data Sheet, Rev. 5.1  
166  
Freescale Semiconductor  
MC68L11E9/E20 Analog-to-Digital Converter Characteristics  
10.14 MC68L11E9/E20 Analog-to-Digital Converter Characteristics  
Characteristic(1)  
Parameter(2)  
Min  
Absolute  
Max  
Unit  
Resolution  
Number of bits resolved by A/D converter  
8
Bits  
Maximum deviation from the ideal A/D transfer  
characteristics  
Non-linearity  
Zero error  
1
1
1
LSB  
LSB  
LSB  
Difference between the output of an ideal and an  
actual for 0 input voltage  
Difference between the output of an ideal and an  
actual A/D for full-scale input voltage  
Full scale error  
Total unadjusted  
error  
Maximum sum of non-linearity, zero error, and  
full-scale error  
1/2  
1/2  
LSB  
LSB  
Quantization error  
Uncertainty because of converter resolution  
Difference between the actual input voltage and  
the full-scale weighted equivalent of the binary  
output code, all error sources included  
Absolute accuracy  
2
LSB  
VRL  
VRL  
VRH  
VDD + 0.1  
VRH  
Conversion range  
Analog input voltage range  
V
V
V
V
VRH  
VRL  
VR  
Maximum analog reference voltage  
Minimum analog reference voltage  
Minimum difference between VRH and VRL  
VSS –0.1  
3.0  
Total time to perform a single  
analog-to-digital conversion:  
E clock  
Conversion time  
tCYC+ 32  
tCYC  
µs  
32  
Internal RC oscillator  
Conversion result never decreases with an  
increase in input voltage and has no missing  
codes  
Monotonicity  
Guaranteed  
Conversion result when VIn = VRL  
Conversion result when VIn = VRH  
Zero input reading  
Full scale reading  
00  
Hex  
Hex  
FF  
Analog input acquisition sampling time:  
E clock  
Sample acquisition  
time  
tCYC  
µs  
12  
12  
Internal RC oscillator  
Sample/hold  
capacitance  
Input capacitance during sample  
PE[7:0]  
20 typical  
pF  
Input leakage on A/D pins  
PE[7:0]  
Input leakage  
400  
1.0  
nA  
µA  
VRL, VRH  
1. VDD = 3.0 Vdc to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH, 750 kHz E 2.0 MHz, unless otherwise noted  
2. Source impedances greater than 10 kaffect accuracy adversely because of input leakage.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
167  
Electrical Characteristics  
10.15 Expansion Bus Timing Characteristics  
1.0 MHz  
2.0 MHz  
3.0 MHz  
Characteristic(1)  
Num  
Symbol  
Unit  
Min  
dc  
Max Min Max Min Max  
fo  
Frequency of operation (E-clock frequency)  
Cycle time  
1.0  
dc  
2.0  
dc  
3.0 MHz  
tCYC  
PWEL  
1
2
1000  
500  
227  
333  
146  
ns  
ns  
Pulse width, E low(2), PWEL = 1/2 tCYC–23 ns  
477  
Pulse width, E high(2), PWEH = 1/2 tCYC–28 ns  
E and AS rise time  
PWEH  
3
4a  
4b  
9
472  
20  
20  
222  
20  
20  
141  
20  
15  
ns  
ns  
ns  
ns  
tr  
tf  
E and AS fall time  
Address hold time(2) (3)a, tAH = 1/8 tCYC–29.5 ns  
tAH  
95.5  
33  
26  
Non-multiplexed address valid time to E rise  
tAV = PWEL –(tASD + 80 ns)(2) (3)a  
tAV  
12  
281.5  
94  
54  
ns  
tDSR  
tDHR  
tDDW  
17  
18  
19  
Read data setup time  
30  
0
30  
0
83  
30  
0
51  
71  
ns  
ns  
ns  
Read data hold time, max = tMAD  
145.5  
190.5  
Write data delay time, tDDW = 1/8 tCYC+ 65.5 ns(2) (3)a  
Write data hold time, tDHW = 1/8 tCYC–29.5 ns(2) (3)a  
128  
tDHW  
tAVM  
21  
22  
95.5  
33  
84  
26  
54  
ns  
ns  
Multiplexed address valid time to E rise  
tAVM = PWEL –(tASD + 90 ns)(2) (3)a  
271.5  
Multiplexed address valid time to AS fall  
tASL  
24  
25  
151  
26  
33  
13  
31  
ns  
ns  
t
ASL = PWASH –70 ns(2)  
Multiplexed address hold time  
AHL = 1/8 tCYC–29.5 ns(2) (3)b  
tAHL  
95.5  
t
Delay time, E to AS rise, tASD = 1/8 tCYC–9.5 ns(2) (3)a  
Pulse width, AS high, PWASH = 1/4 tCYC–29 ns(2)  
Delay time, AS to E rise, tASED = 1/8 tCYC–9.5 ns(2) (3)b  
tASD  
PWASH  
tASED  
26  
27  
28  
115.5  
221  
53  
96  
53  
31  
63  
31  
ns  
ns  
ns  
115.5  
MPU address access time(3)a  
tACCA  
tACCE  
tMAD  
29  
35  
36  
744.5  
442  
307  
192  
196  
111  
ns  
ns  
ns  
tACCA = tCYC–(PWEL–tAVM) –tDSR–tf  
MPU access time, tACCE = PWEH –tDSR  
Multiplexed address delay (Previous cycle MPU read)  
tMAD = tASD + 30 ns(2) (3)a  
145.5  
83  
51  
1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH, all timing is shown with respect to 20% VDD and 70% VDD, unless oth-  
erwise noted  
2. Formula only for dc to 2 MHz  
3. Input clocks with duty cycles other than 50% affect bus performance. Timing parameters affected by input clock duty cycle  
are identified by (a) and (b). To recalculate the approximate bus timing values, substitute the following expressions in place  
of 1/8 tCYCin the above formulas, where applicable:  
(a) (1–dc) × 1/4 tCYC  
(b) dc × 1/4 tCYC  
Where:  
dc is the decimal value of duty cycle percentage (high time)  
M68HC11E Family Data Sheet, Rev. 5.1  
168  
Freescale Semiconductor  
MC68L11E9/E20 Expansion Bus Timing Characteristics  
10.16 MC68L11E9/E20 Expansion Bus Timing Characteristics  
1.0 MHz  
2.0 MHz  
Characteristic(1)  
Num  
Symbol  
Unit  
Min  
Max  
1.0  
Min  
Max  
2.0  
fo  
tCYC  
PWEL  
PWEH  
tr  
Frequency of operation (E-clock frequency)  
Cycle time  
dc  
1000  
475  
470  
dc  
500  
225  
220  
MHz  
ns  
1
2
Pulse width, E low, PWEL = 1/2 tCYC–25 ns  
Pulse width, E high, PWEH = 1/2 tCYC–30 ns  
ns  
3
ns  
4a  
4b  
9
E and AS rise time  
E and AS fall time  
25  
25  
ns  
tf  
25  
25  
ns  
Address hold time(2) (2)a, tAH = 1/8 tCYC–30 ns  
tAH  
95  
33  
ns  
Non-multiplexed address valid time to E rise  
tAV = PWEL –(tASD + 80 ns)(2)a  
tAV  
12  
275  
88  
ns  
tDSR  
tDHR  
tDDW  
17  
18  
19  
Read data setup time  
30  
0
30  
0
88  
ns  
ns  
ns  
Read data hold time , max = tMAD  
150  
195  
Write data delay time, tDDW = 1/8 tCYC+ 70 ns(2)a  
Write data hold time, tDHW = 1/8 tCYC–30 ns(2)a  
133  
tDHW  
tAVM  
21  
22  
95  
33  
78  
ns  
ns  
Multiplexed address valid time to E rise  
tAVM = PWEL –(tASD + 90 ns)(2)a  
268  
Multiplexed address valid time to AS fall  
tASL = PWASH –70 ns  
tASL  
24  
150  
25  
ns  
Multiplexed address hold time, tAHL = 1/8 tCYC–30 ns(2)b  
tAHL  
tASD  
25  
26  
27  
28  
95  
33  
58  
95  
58  
ns  
ns  
ns  
ns  
Delay time, E to AS rise, tASD = 1/8 tCYC–5 ns(2)a  
Pulse width, AS high, PWASH = 1/4 tCYC–30 ns  
120  
220  
120  
PWASH  
tASED  
Delay time, AS to E rise, tASED = 1/8 tCYC–5 ns(2)b  
MPU address access time(3)a  
tACCA  
tACCE  
tMAD  
29  
35  
36  
735  
440  
298  
190  
ns  
ns  
ns  
tACCA = tCYC–(PWEL–tAVM) –tDSR–tf  
MPU access time, tACCE = PWEH –tDSR  
Multiplexed address delay (Previous cycle MPU read)  
tMAD = tASD + 30 ns(2)a  
150  
88  
1. VDD = 3.0 Vdc to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH, all timing is shown with respect to 20% VDD and 70% VDD, unless  
otherwise noted  
2. Input clocks with duty cycles other than 50% affect bus performance. Timing parameters affected by input clock duty cycle  
are identified by (a) and (b). To recalculate the approximate bus timing values, substitute the following expressions in place  
of 1/8 tCYCin the above formulas, where applicable:  
(a) (1–dc) × 1/4 tCYC  
(b) dc × 1/4 tCYC  
Where:  
dc is the decimal value of duty cycle percentage (high time).  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
169  
Electrical Characteristics  
1
2  
3  
4B  
E
4A  
12  
9
R/W, ADDRESS  
NON-MULTIPLEXED  
22  
17  
35  
36  
18  
29  
READ  
ADDRESS  
DATA  
ADDRESS/DATA  
MULTIPLEXED
1
9
21  
W
R
I
E
A
D
D
R
E
S
S
DATA  
25  
4A  
24  
4B  
AS  
28  
26  
27  
Note: Measurement points shown are 20% and 70% of VDD  
.
Figure 10-14. Multiplexed Expansion Bus Timing Diagram  
M68HC11E Family Data Sheet, Rev. 5.1  
170  
Freescale Semiconductor  
Serial Peripheral Interface Timing Characteristics  
10.17 Serial Peripheral Interface Timing Characteristics  
E9  
E20  
Characteristic(1)  
Num  
Symbol  
Unit  
Min  
dc  
Max  
3.0  
Min  
dc  
Max  
3.0  
Frequency of operation  
E clock  
fo  
MHz  
ns  
tCYC  
E-clock period  
333  
333  
Operating frequency  
Master  
fop(m)  
fop(s)  
fo/2  
fo  
fo/2  
fo  
fo/32  
dc  
fo/128  
dc  
MHz  
tCYC  
Slave  
Cycle time  
Master  
tCYC(m)  
tCYC(s)  
1
2
1
32  
2
1
128  
Slave  
Enable lead time(2)  
Slave  
tlead(s)  
tlag(s)  
tCYC  
tCYC  
2
3
1
1
1
1
Enable lag time(2)  
Slave  
Clock (SCK) high time  
tCYC–25  
1/2  
tCYC–25  
tCYC–25  
1/2  
tCYC–25  
tw(SCKH)m  
tw(SCKH)s  
16 tCYC  
64 tCYC  
4
5
Master  
Slave  
ns  
ns  
Clock (SCK) low time  
Master  
tCYC–25  
1/2  
tCYC–25  
tCYC–25  
1/2  
tCYC–25  
tw(SCKL)m  
tw(SCKL)s  
16 tCYC  
64 tCYC  
Slave  
Data setup time (inputs)  
tsu(m)  
tsu(s)  
6
7
Master  
Slave  
30  
30  
30  
30  
ns  
ns  
Data hold time (inputs)  
th(m)  
th(s)  
Master  
Slave  
30  
30  
30  
30  
Slave access time  
CPHA = 0  
ta  
8
9
0
0
40  
40  
0
0
40  
40  
ns  
ns  
CPHA = 1  
Disable time (hold time  
to high-impedance state)  
Slave  
tdis  
50  
50  
Data valid(3) (after enable edge)  
tv  
10  
11  
0
50  
0
50  
ns  
ns  
Data hold time (outputs)  
(after enable edge)  
tho  
1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH, all timing is shown with respect to 20% VDD and 70% VDD, unless other-  
wise noted  
2. Time to data active from high-impedance state  
3. Assumes 200 pF load on SCK, MOSI, and MISO pins  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
171  
Electrical Characteristics  
10.18 MC68L11E9/E20 Serial Peirpheral Interface Characteristics  
E9  
E20  
Characteristic(1)  
Num  
Symbol  
Unit  
Min  
dc  
Max  
2.0  
Min  
dc  
Max  
2.0  
Frequency of operation  
E clock  
fo  
MHz  
ns  
tCYC  
E-clock period  
500  
500  
Operating frequency  
Master  
fop(m)  
fop(s)  
fo/2  
fo  
fo/2  
fo  
fo/32  
dc  
fo/128  
dc  
MHz  
tCYC  
Slave  
Cycle time  
Master  
tCYC(m)  
tCYC(s)  
1
2
1
32  
2
1
128  
Slave  
Enable lead time(2)  
Slave  
tlead(s)  
tlag(s)  
tCYC  
tCYC  
2
3
1
1
1
1
Enable lag time(2)  
Slave  
Clock (SCK) high time  
tCYC–30  
1/2  
tCYC–30  
tCYC–30  
1/2  
tCYC–30  
tw(SCKH)m  
tw(SCKH)s  
16 tCYC  
64 tCYC  
4
5
Master  
Slave  
ns  
ns  
Clock (SCK) low time  
Master  
tCYC–30  
1/2  
tCYC–30  
tCYC–30  
1/2  
tCYC–30  
tw(SCKL)m  
tw(SCKL)s  
16 tCYC  
64 tCYC  
Slave  
Data setup time (inputs)  
tsu(m)  
tsu(s)  
6
7
Master  
Slave  
40  
40  
40  
40  
ns  
ns  
Data hold time (inputs)  
th(m)  
th(s)  
Master  
Slave  
40  
40  
40  
40  
Slave access time  
CPHA = 0  
ta  
8
9
0
0
50  
50  
0
0
50  
50  
ns  
ns  
CPHA = 1  
Disable time (hold time  
to high-impedance state)  
Slave  
tdis  
60  
60  
Data valid(3) (after enable edge)  
tv  
10  
11  
0
60  
0
60  
ns  
ns  
Data hold time (outputs)  
(after enable edge)  
tho  
1. VDD = 3.0 Vdc to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH, all timing is shown with respect to 20% VDD and 70% VDD, unless  
otherwise noted  
2. Time to data active from high-impedance state  
3. Assumes 100 pF load on SCK, MOSI, and MISO pins  
M68HC11E Family Data Sheet, Rev. 5.1  
172  
Freescale Semiconductor  
MC68L11E9/E20 Serial Peirpheral Interface Characteristics  
SS  
INPUT  
SS IS HELD HIGH ON MASTER.  
1
SCK  
CPOL = 0  
INPUT  
5
4
SEE NOTE  
SEE NOTE  
4
5
SCK  
CPOL = 1  
OUTPUT  
6
7
MISO  
INPUT  
BIT 6 . . . 1  
11  
MSB IN  
LSB IN  
11 (REF)  
10  
MOSI  
OUTPUT  
BIT 6 . . . 1  
MASTER MSB OUT  
MASTER LSB OUT  
Note: This first clock edge is generated internally but is not seen at the SCK pin.  
A) SPI Master Timing (CPHA = 0)  
SS  
SS IS HELD HIGH ON MASTER.  
INPUT  
1
SCK  
CPOL = 0  
INPUT  
5
SEE NOTE  
4
5
SCK  
CPOL = 1  
OUTPUT  
SEE NOTE  
7
4
6
MISO  
INPUT  
BIT 6 . . . 1  
11  
MSB IN  
LSB IN  
11 (REF)  
10  
10 (REF)  
MOSI  
OUTPUT  
BIT 6 . . . 1  
MASTER MSB OUT  
MASTER LSB OUT  
Note: This first clock edge is generated internally but is not seen at the SCK pin.  
B) SPI Master Timing (CPHA = 1)  
Figure 10-15. SPI Timing Diagram (Sheet 1 of 2)  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
173  
Electrical Characteristics  
SS  
INPUT  
1
3
SCK  
CPOL = 0  
INPUT  
5
4
4
5
2
SCK  
CPOL = 1  
INPUT  
8
9
MISO  
OUTPUT  
SEE  
NOTE  
BIT 6 . . . 1  
SLAVE LSB OUT  
MSB OUT  
7
SLAVE  
6
10  
11  
11  
MOSI  
INPUT  
BIT 6 . . . 1  
MSB IN  
LSB IN  
Note: Not defined but normally MSB of character just received  
A) SPI Slave Timing (CPHA = 0)  
SS  
INPUT  
1
3
SCK  
CPOL = 0  
INPUT  
5
4
5
2
SCK  
CPOL = 1  
INPUT  
8
10  
SLAVE  
6
4
MSB OUT  
7
9
MISO  
OUTPUT  
SEE  
NOTE  
BIT 6 . . . 1  
10  
SLAVE LSB OUT  
11  
MOSI  
INPUT  
BIT 6 . . . 1  
MSB IN  
LSB IN  
Note: Not defined but normally LSB of character previously transmitted  
B) SPI Slave Timing (CPHA = 1)  
Figure 11-15. SPI Timing Diagram (Sheet 2 of 2)  
M68HC11E Family Data Sheet, Rev. 5.1  
174  
Freescale Semiconductor  
EEPROM Characteristics  
10.19 EEPROM Characteristics  
Temperature Range  
Characteristic(1)  
Unit  
–40 to 85°C  
–40 to 105°C  
–40 to 125°C  
Programming time(2)  
10  
20  
10  
15  
Must use RCO  
15  
20  
ms  
< 1.0 MHz, RCO enabled  
1.0 to 2.0 MHz, RCO disabled  
2.0 MHz (or anytime RCO enabled)  
Must use RCO  
20  
Erase time(2)  
10  
10  
10  
ms  
Byte, row, and bulk  
Write/erase endurance  
Data retention  
10,000  
10  
10,000  
10  
10,000  
10  
Cycles  
Years  
1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH  
2. The RC oscillator (RCO) must be enabled (by setting the CSEL bit in the OPTION register) for EEPROM programming and  
erasure when the E-clock frequency is below 1.0 MHz.  
10.20 MC68L11E9/E20 EEPROM Characteristics  
Temperature Range  
Characteristic(1)  
Unit  
–20 to 70°C  
Programming time(2)  
25  
10  
ms  
ms  
3 V, E 2.0 MHz, RCO enabled  
5 V, E 2.0 MHz, RCO enabled  
Erase time(2) (byte, row, and bulk)  
3 V, E 2.0 MHz, RCO enabled  
5 V, E 2.0 MHz, RCO enabled  
25  
10  
Write/erase endurance  
10,000  
10  
Cycles  
Years  
Data retention  
1. VDD = 3.0 Vdc to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH  
2. The RC oscillator (RCO) must be enabled (by setting the CSEL bit in the OPTION register) for EEPROM programming and  
erasure.  
10.21 EPROM Characteristics  
Characteristics(1)  
Programming voltage(2)  
Symbol  
Min  
11.75  
Typ  
12.25  
3
Max  
12.75  
10  
Unit  
V
VPPE  
Programming current(3)  
IPPE  
mA  
ms  
tEPROG  
Programming time  
2
2
4
1. VDD = 5.0 Vdc 10%  
2. During EPROM programming of the MC68HC711E9 device, the VPPE pin circuitry may latch-up and be damaged if the  
input current is not limited to 10 mA. For more information please refer to MC68HC711E9 8-Bit Microcontroller Unit Mask  
Set Errata 3 (Freescale document order number 68HC711E9MSE3.  
3. Typically, a 1-kseries resistor is sufficient to limit the programming current for the MC68HC711E9. A 100-series resis-  
tor is sufficient to limit the programming current for the MC68HC711E20.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
175  
Electrical Characteristics  
M68HC11E Family Data Sheet, Rev. 5.1  
176  
Freescale Semiconductor  
Chapter 11  
Ordering Information and Mechanical Specifications  
11.1 Introduction  
This section provides ordering information for the E-series devices grouped by:  
Standard devices  
Custom ROM devices  
Extended voltage devices  
In addition, mechanical specifications for the following packaging options:  
52-pin plastic-leaded chip carrier (PLCC)  
52-pin windowed ceramic-leaded chip carrier (CLCC)  
64-pin quad flat pack (QFP)  
52-pin thin quad flat pack (TQFP)  
56-pin shrink dual in-line package with .070-inch lead spacing (SDIP)  
48-pin plastic DIP (.100-inch lead spacing), MC68HC811E2 only  
11.2 Standard Device Ordering Information  
Description  
CONFIG  
Temperature  
Frequency  
MC Order Number  
52-pin plastic leaded chip carrier (PLCC)  
2 MHz  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
MC68HC11E9BCFN2  
MC68HC11E9BCFN3  
MC68HC11E1CFN2  
MC68HC11E1CFN3  
MC68HC11E1VFN2  
MC68HC11E1MFN2  
MC68HC11E0CFN2  
MC68HC11E0CFN3  
MC68HC11E0VFN2  
MC68HC11E0MFN2  
BUFFALO ROM  
No ROM  
$0F  
$0D  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +105°C  
–40°C to +125°C  
–40°C to +85°C  
No ROM, no EEPROM  
$0C  
–40°C to +105°C  
–40°C to +125°C  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
177  
Ordering Information and Mechanical Specifications  
Description  
CONFIG  
Temperature  
Frequency  
MC Order Number  
52-pin plastic leaded chip carrier (PLCC) (Continued)  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
MC68HC711E9CFN2  
MC68HC711E9CFN3  
MC68HC711E9VFN2  
MC68HC711E9MFN2  
–40°C to +85°C  
OTPROM  
$0F  
$0F  
–40°C to +105°C  
–40°C to +125°C  
OTPROM, enhanced security  
feature  
–40°C to +85°C  
0°C to +70°C  
2 MHz  
MC68S711E9CFN2  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
2 MHz  
2 MHz  
2 MHz  
2 MHz  
MC68HC711E20FN3  
MC68HC711E20CFN2  
MC68HC711E20CFN3  
MC68HC711E20VFN2  
MC68HC711E20MFN2  
MC68HC811E2FN2  
–40°C to +85°C  
20 Kbytes OTPROM  
$0F  
$FF  
–40°C to +105°C  
–40°C to +125°C  
0°C to +70°C  
–40°C to +85°C  
–40°C to +105°C  
–40°C to +125°C  
MC68HC811E2CFN2  
MC68HC811E2VFN2  
MC68HC811E2MFN2  
No ROM, 2 Kbytes EEPROM  
64-pin quad flat pack (QFP)  
2 MHz  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
2 MHz  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
MC68HC11E9BCFU2  
MC68HC11E9BCFU3  
MC68HC11E1CFU2  
MC68HC11E1CFU3  
MC68HC11E1VFU2  
MC68HC11E0CFU2  
MC68HC11E0VFU2  
MC68HC711E20FU3  
MC68HC711E20CFU2  
MC68HC711E20CFU3  
MC68HC711E20VFU2  
MC68HC711E20MFU2  
BUFFALO ROM  
$0F  
$0D  
$0C  
–40°C to +85°C  
–40°C to +85°C  
No ROM  
–40°C to +105°C  
–40°C to +85°C  
–40°C to +105°C  
0°C to +70°°C  
No ROM, no EEPROM  
–40°C to +85°C  
20 Kbytes OTPROM  
$0F  
$0F  
–40°C to +105°C  
–40°C to +125°C  
52-pin thin quad flat pack (TQFP)  
2 MHz  
3 MHz  
MC68HC11E9BCPB2  
MC68HC11E9BCPB3  
BUFFALO ROM  
–40°C to +85°C  
M68HC11E Family Data Sheet, Rev. 5.1  
178  
Freescale Semiconductor  
Custom ROM Device Ordering Information  
Description  
CONFIG  
Temperature  
Frequency  
MC Order Number  
52-pin windowed ceramic leaded chip carrier (CLCC)  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
MC68HC711E9CFS2  
MC68HC711E9CFS3  
MC68HC711E9VFS2  
MC68HC711E9VFS2  
MC68HC711E20FS3  
MC68HC711E20CFS2  
MC68HC711E20CFS3  
MC68HC711E20VFS2  
MC68HC711E20MFS2  
–40°C to +85°C  
EPROM  
$0F  
$0F  
–40°C to +105°C  
–40°C to +125°C  
0°C o +70°°C  
–40°C to +85°C  
20 Kbytes EPROM  
–40°C to +105°C  
–40°C to +125°C  
48-pin dual in-line package (DIP) — MC68HC811E2 only  
0°C to +70°°C  
2 MHz  
2 MHz  
2 MHz  
2 MHz  
MC68HC811E2P2  
MC68HC811E2CP2  
MC68HC811E2VP2  
MC68HC811E2MP2  
–40°C to +85°C  
–40°C to +105°C  
–40°C to +125°C  
No ROM, 2 Kbytes EEPROM  
$FF  
56-pin dual in-line package with 0.70-inch lead spacing (SDIP)  
2 MHz  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
MC68HC11E9BCB2  
MC68HC11E9BCB3  
MC68HC11E1CB2  
MC68HC11E1CB3  
MC68HC11E1VB2  
MC68HC11E1MB2  
MC68HC11E0CB2  
MC68HC11E0CB3  
MC68HC11E0VB2  
MC68HC11E0MB2  
BUFFALO ROM  
$0F  
–40°C to +85°C  
–40°C to +85°C  
No ROM  
$0D  
–40°C to +105°C  
–40°C to +125°C  
–40°C to +85°C  
No ROM, no EEPROM  
$0C  
–40°C to +105°C  
–40°C to +125°C  
11.3 Custom ROM Device Ordering Information  
Description  
Temperature  
Frequency  
MC Order Number  
52-pin plastic leaded chip carrier (PLCC)  
0°C to +70°°C  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
MC68HC11E9FN3  
MC68HC11E9CFN2  
MC68HC11E9CFN3  
MC68HC11E9VFN2  
MC68HC11E9MFN2  
–40°C to +85°C  
Custom ROM  
–40°C to +105°C  
–40°C to +125°C  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
179  
Ordering Information and Mechanical Specifications  
Description  
20 Kbytes custom ROM  
64-pin quad flat pack (QFP)  
Custom ROM  
Temperature  
Frequency  
3 MHz  
MC Order Number  
MC68HC11E20FN3  
MC68HC11E20CFN2  
MC68HC11E20CFN3  
MC68HC11E20VFN2  
MC68HC11E20MFN2  
0°C to +70°°C  
2 MHz  
–40°C to +85°C  
3 MHz  
–40°C to +105°C  
–40°C to +125°C  
2 MHz  
2 MHz  
0°C to +70°°C  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
MC68HC11E9FU3  
MC68HC11E9CFU2  
MC68HC11E9CFU3  
MC68HC11E9VFU2  
MC68HC11E9MFU2  
–40°C to +85°C  
–40°C to +105°C  
–40°C to +125°C  
64-pin quad flat pack (continued)  
20 Kbytes Custom ROM  
0°C to +70°°C  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
MC68HC11E20FU3  
MC68HC11E20CFU2  
MC68HC11E20CFU3  
MC68HC11E20VFU2  
MC68HC11E20MFU2  
–40°C to +85°C  
–40°C to +105°C  
–40°C to +125°C  
52-pin thin quad flat pack (10 mm x 10 mm)  
0°C to +70°°C  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
MC68HC11E9PB3  
MC68HC11E9CPB2  
MC68HC11E9CPB3  
MC68HC11E9VPB2  
MC68HC11E9MPB2  
–40°C to +85°C  
Custom ROM  
–40°C to +105°C  
–40°C to +125°C  
56-pin dual in-line package with 0.70-inch lead spacing (SDIP)  
0°C to +70°°C  
3 MHz  
2 MHz  
3 MHz  
2 MHz  
2 MHz  
MC68HC11E9B3  
MC68HC11E9CB2  
MC68HC11E9CB3  
MC68HC11E9VB2  
MC68HC11E9MB2  
–40°C to +85°C  
Custom ROM  
–40°C to +105°C  
–40°C to +125°C  
M68HC11E Family Data Sheet, Rev. 5.1  
180  
Freescale Semiconductor  
Extended Voltage Device Ordering Information (3.0 Vdc to 5.5 Vdc)  
11.4 Extended Voltage Device Ordering Information (3.0 Vdc to 5.5 Vdc)  
Description  
Temperature  
Frequency  
MC Order Number  
52-pin plastic leaded chip carrier (PLCC)  
MC68L11E9FN2  
MC68L11E20FN2  
Custom ROM  
2 MHz  
–20°C to +70°C  
No ROM  
2 MHz  
2 MHz  
MC68L11E1FN2  
MC68L11E0FN2  
No ROM, no EEPROM  
64-pin quad flat pack (QFP)  
MC68L11E9FU2  
MC68L11E20FU2  
Custom ROM  
2 MHz  
–20°C to +70°C  
–20°C to +70°C  
No ROM  
2 MHz  
2 MHz  
MC68L11E1FU2  
MC68L11E0FU2  
No ROM, no EEPROM  
52-pin thin quad flat pack (10 mm x 10 mm)  
Custom ROM  
2 MHz  
2 MHz  
2 MHz  
MC68L11E9PB2  
MC68L11E1PB2  
MC68L11E0PB2  
No ROM  
No ROM, no EEPROM  
56-pin dual in-line package with 0.70-inch lead spacing (SDIP)  
Custom ROM  
2 MHz  
2 MHz  
2 MHz  
MC68L11E9B2  
MC68L11E1B2  
MC68L11E0B2  
No ROM  
–20°C to +70°C  
No ROM, no EEPROM  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
181  
Ordering Information and Mechanical Specifications  
11.5 52-Pin Plastic-Leaded Chip Carrier (Case 778)  
M
S
S
0.007 (0.18)  
T
L–M  
N
B
Y BRK  
–N–  
M
S
S
0.007 (0.18)  
T
L–M  
N
U
D
Z
–M–  
–L–  
W
D
G1  
52  
1
X
S
S
S
0.010 (0.25)  
T
L–M  
N
V
VIEW D–D  
NOTES:  
M
M
S
S
1. DATUMS –L–, –M–, AND –N– DETERMINED WHERE  
TOP OF LEAD SHOULDER EXITS PLASTIC BODY AT  
MOLD PARTING LINE.  
2. DIMENSION G1, TRUE POSITION TO BE MEASURED  
AT DATUM –T–, SEATING PLANE.  
0.007 (0.18)  
0.007 (0.18)  
T
T
L–M  
L–M  
N
A
R
Z
S
S
N
3. DIMENSIONS R AND U DO NOT INCLUDE MOLD  
FLASH. ALLOWABLE MOLD FLASH IS 0.010 (0.250)  
PER SIDE.  
4. DIMENSIONING AND TOLERANCING PER ANSI  
Y14.5M, 1982.  
5. CONTROLLING DIMENSION: INCH.  
E
C
0.004 (0.100)  
6. THE PACKAGE TOP MAY BE SMALLER THAN THE  
PACKAGE BOTTOM BY UP TO 0.012 (0.300).  
DIMENSIONS R AND U ARE DETERMINED AT THE  
OUTERMOST EXTREMES OF THE PLASTIC BODY  
EXCLUSIVE OF MOLD FLASH, TIE BAR BURRS, GATE  
BURRS AND INTERLEAD FLASH, BUT INCLUDING  
ANY MISMATCH BETWEEN THE TOP AND BOTTOM  
OF THE PLASTIC BODY.  
–T– SEATING  
J
G
PLANE  
VIEW S  
G1  
S
S
S
0.010 (0.25)  
T
L–M  
N
7. DIMENSION H DOES NOT INCLUDE DAMBAR  
PROTRUSION OR INTRUSION. THE DAMBAR  
PROTRUSION(S) SHALL NOT CAUSE THE H  
DIMENSION TO BE GREATER THAN 0.037 (0.940).  
THE DAMBAR INTRUSION(S) SHALL NOT CAUSE THE  
H DIMENSION TO BE SMALLER THAN 0.025 (0.635).  
M
S
S
H
F
0.007 (0.18)  
0.007 (0.18)  
T
L–M  
N
INCHES  
MILLIMETERS  
K1  
K
DIM  
A
B
C
E
MIN  
MAX  
0.795  
0.795  
0.180  
0.110  
0.019  
MIN  
19.94  
19.94  
4.20  
2.29  
0.33  
MAX  
20.19  
20.19  
4.57  
2.79  
0.48  
0.785  
0.785  
0.165  
0.090  
0.013  
M
S
S
T
L–M  
N
F
G
H
J
K
R
U
V
W
X
Y
0.050 BSC  
1.27 BSC  
VIEW S  
0.026  
0.020  
0.025  
0.750  
0.750  
0.042  
0.042  
0.042  
–––  
0.032  
–––  
–––  
0.756  
0.756  
0.048  
0.048  
0.056  
0.020  
10  
0.66  
0.51  
0.64  
19.05  
19.05  
1.07  
1.07  
1.07  
–––  
0.81  
–––  
–––  
19.20  
19.20  
1.21  
1.21  
1.42  
0.50  
10  
Z
2
2
G1  
K1  
0.710  
0.040  
0.730  
–––  
18.04  
1.02  
18.54  
–––  
M68HC11E Family Data Sheet, Rev. 5.1  
182  
Freescale Semiconductor  
52-Pin Windowed Ceramic-Leaded Chip Carrier (Case 778B)  
11.6 52-Pin Windowed Ceramic-Leaded Chip Carrier (Case 778B)  
NOTES:  
-A-  
R
1. DIMENSIONING AND TOLERANCING PER  
ANSI Y14.5M, 1982.  
2. CONTROLLING DIMENSION: INCH.  
3. DIMENSION R AND N DO NOT INCLUDE  
GLASS PROTRUSION. GLASS PROTRUSION  
TO BE 0.25 (0.010) MAXIMUM.  
M
S
S
B
0.51 (0.020)  
T A  
4. ALL DIMENSIONS AND TOLERANCES  
INCLUDE LEAD TRIM OFFSET AND LEAD  
INCHES  
DIM MIN MAX  
MILLIMETERS  
MIN  
19.94  
19.94  
4.20  
MAX  
20.19  
20.19  
5.08  
A
B
C
D
F
0.785  
0.785  
0.165  
0.017  
0.026  
0.795  
0.795  
0.200  
0.021  
0.032  
N
-B-  
0.44  
0.67  
0.53  
0.81  
G
H
J
K
N
R
S
0.050 BSC  
1.27 BSC  
0.090  
0.006  
0.035  
0.735  
0.735  
0.690  
0.130  
0.010  
0.045  
0.756  
0.756  
0.730  
2.29  
0.16  
3.30  
0.25  
0.89  
1.14  
18.67  
18.67  
17.53  
19.20  
19.20  
18.54  
M
S
S
0.51 (0.020)  
T A  
B
F
K
H
0.15 (0.006)  
C
G
-T- SEATING  
PLANE  
J
D 52 PL  
M
S
S
B
0.18 (0.007)  
T A  
S
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
183  
Ordering Information and Mechanical Specifications  
11.7 64-Pin Quad Flat Pack (Case 840C)  
B
B
L
–A–, –B–, –D–  
33  
48  
32  
49  
P
B
L
V
DETAIL A  
F
BASE  
METAL  
DETAIL A  
J
N
17  
64  
D
16  
1
M
S
S
D
0.20 (0.008)  
C A–B  
–D–  
SECTION B–B  
A
NOTES:  
M
S
S
S
0.20 (0.008)  
H A–B  
D
D
1. DIMENSIONING AND TOLERANCING PER ANSI  
Y14.5M, 1982.  
2. CONTROLLING DIMENSION: MILLIMETER.  
3. DATUM PLANE –H– IS LOCATED AT BOTTOM OF  
LEAD AND IS COINCIDENT WITH THE LEAD  
WHERE THE LEAD EXITS THE PLASTIC BODY AT  
THE BOTTOM OF THE PARTING LINE.  
0.05 (0.002) A–B  
S
M
S
C A–B  
0.20 (0.008)  
4. DATUMS A–B AND –D– TO BE DETERMINED AT  
DATUM PLANE –H–.  
5. DIMENSIONS S AND V TO BE DETERMINED AT  
SEATING PLANE –C–.  
6. DIMENSIONS A AND B DO NOT INCLUDE MOLD  
PROTRUSION. ALLOWABLE PROTRUSION IS 0.25  
(0.010) PER SIDE. DIMENSIONS A AND B DO  
INCLUDE MOLD MISMATCH AND ARE  
–H–  
DATUM PLANE  
C E  
DETERMINED AT DATUM PLANE –H–.  
7. DIMENSION D DOES NOT INCLUDE DAMBAR  
PROTRUSION. DAMBAR PROTRUSION SHALL  
NOT CAUSE THE D DIMENSION TO EXCEED 0.53  
(0.021). DAMBAR CANNOT BE LOCATED ON THE  
LOWER RADIUS OR THE FOOT.  
8. DIMENSION K IS TO BE MEASURED FROM THE  
THEORETICAL INTERSECTION OF LEAD FOOT  
AND LEG CENTERLINES.  
0.10 (0.004)  
SEATING PLANE  
–C–  
H
G
DETAIL C  
U
MILLIMETERS  
INCHES  
M
DIM MIN  
MAX  
14.10  
14.10  
2.46  
MIN  
MAX  
0.555  
0.555  
0.097  
0.018  
0.094  
–––  
T
A
B
C
D
E
F
13.90  
13.90  
2.07  
0.30  
2.00  
0.30  
0.547  
0.547  
0.081  
0.012  
0.079  
0.45  
2.40  
R
––– 0.012  
G
H
J
K
L
M
N
P
Q
R
S
T
0.80 BSC  
0.031 BSC  
0.067  
0.130  
0.50  
0.250  
0.230  
0.66  
0.003  
0.005  
0.020  
0.010  
0.090  
0.026  
Q
12.00 REF  
0.472 REF  
SEATING PLANE  
5
0.130  
10  
0.170  
5
0.005  
10  
0.007  
K
0.40 BSC  
0.016 BSC  
2
2
0.13  
16.20  
8
0.30  
16.60  
8
0.005  
0.638  
0.012  
0.654  
X
M
0.20 REF  
0.008 REF  
U
V
X
0
16.20  
1.10  
–––  
16.60  
1.30  
0
–––  
0.654  
0.051  
0.638  
0.043  
DETAIL C  
M68HC11E Family Data Sheet, Rev. 5.1  
184  
Freescale Semiconductor  
52-Pin Thin Quad Flat Pack (Case 848D)  
11.8 52-Pin Thin Quad Flat Pack (Case 848D)  
4X  
4X TIPS  
0.20 (0.008) H L–M  
N
0.20 (0.008) T L–M N  
–X–  
X=L, M, N  
52  
40  
C
1
39  
L
AB  
AB  
G
3X VIEW Y  
–L–  
–M–  
B1  
B
V
VIEW Y  
F
BASE METAL  
PLATING  
V1  
13  
27  
J
U
14  
26  
–N–  
D
A1  
M
S
S
0.13 (0.005)  
T
L–M  
N
S1  
SECTION AB–AB  
A
ROTATED 90 CLOCKWISE  
S
NOTES:  
1. DIMENSIONING AND TOLERANCING PER ANSI  
Y14.5M, 1982.  
2. CONTROLLING DIMENSION: MILLIMETER.  
3. DATUM PLANE –H– IS LOCATED AT BOTTOM OF  
LEAD AND IS COINCIDENT WITH THE LEAD  
WHERE THE LEAD EXITS THE PLASTIC BODY AT  
THE BOTTOM OF THE PARTING LINE.  
4. DATUMS –L–, –M– AND –N– TO BE DETERMINED  
AT DATUM PLANE –H–.  
4X θ2  
4X θ3  
C
0.10 (0.004)  
T
–H–  
5. DIMENSIONS S AND V TO BE DETERMINED AT  
SEATING PLANE –T–.  
–T–  
SEATING  
PLANE  
6. DIMENSIONS A AND B DO NOT INCLUDE MOLD  
PROTRUSION. ALLOWABLE PROTRUSION IS  
0.25 (0.010) PER SIDE. DIMENSIONS A AND B  
DO INCLUDE MOLD MISMATCH AND ARE  
DETERMINED AT DATUM PLANE -H-.  
VIEW AA  
7. DIMENSION D DOES NOT INCLUDE DAMBAR  
PROTRUSION. DAMBAR PROTRUSION SHALL  
NOT CAUSE THE LEAD WIDTH TO EXCEED 0.46  
(0.018). MINIMUM SPACE BETWEEN  
PROTRUSION AND ADJACENT LEAD OR  
PROTRUSION 0.07 (0.003).  
S
0.05 (0.002)  
MILLIMETERS  
DIM MIN MAX  
10.00 BSC  
INCHES  
MIN MAX  
0.394 BSC  
0.197 BSC  
0.394 BSC  
0.197 BSC  
W
θ1  
2 X R R1  
A
A1  
B
5.00 BSC  
10.00 BSC  
5.00 BSC  
0.25 (0.010)  
C2  
B1  
C
θ
–––  
0.05  
1.30  
0.20  
0.45  
0.22  
1.70  
–––  
0.002  
0.051  
0.008  
0.018  
0.009  
0.067  
GAGE PLANE  
C1  
C2  
D
E
F
0.20  
1.50  
0.40  
0.75  
0.35  
0.008  
0.059  
0.016  
0.030  
0.014  
K
E
C1  
G
J
0.65 BSC  
0.026 BSC  
0.07  
0.20  
0.003  
0.008  
Z
K
R1  
S
S1  
U
0.50 REF  
0.020 REF  
0.08  
0.20  
0.003  
0.008  
VIEW AA  
12.00 BSC  
6.00 BSC  
0.09 0.16  
0.472 BSC  
0.236 BSC  
0.004 0.006  
V
12.00 BSC  
6.00 BSC  
0.20 REF  
1.00 REF  
0.472 BSC  
0.236 BSC  
0.008 REF  
0.039 REF  
V1  
W
Z
θ
0
0
12  
7
–––  
0
0
12  
7
–––  
θ1  
θ2  
θ3  
REF  
13  
REF  
13  
5
5
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
185  
Ordering Information and Mechanical Specifications  
11.9 56-Pin Dual in-Line Package (Case 859)  
–A–  
NOTES:  
1. DIMENSIONING AND TOLERANCING PER ANSI  
Y14.5M, 1982.  
56  
29  
28  
2. CONTROLLING DIMENSION: INCH.  
3. DIMENSION L TO CENTER OF LEAD WHEN  
FORMED PARALLEL.  
4. DIMENSIONS A AND B DO NOT INCLUDE MOLD  
FLASH. MAXIMUM MOLD FLASH 0.25 (0.010)  
–B–  
INCHES  
DIM MIN MAX  
MILLIMETERS  
1
MIN  
51.69  
13.72  
3.94  
MAX  
52.45  
14.22  
5.08  
A
B
C
D
E
F
2.035  
0.540  
0.155  
0.014  
2.065  
0.560  
0.200  
0.022  
L
0.36  
0.56  
H
C
0.035 BSC  
0.89 BSC  
0.032  
0.046  
0.81  
1.17  
G
H
J
K
L
0.070 BSC  
0.300 BSC  
1.778 BSC  
7.62 BSC  
–T–  
SEATING  
PLANE  
K
0.008  
0.115  
0.015  
0.135  
0.20  
2.92  
0.38  
3.43  
0.600 BSC  
15.24 BSC  
N
G
M
F
M
N
0
0.020  
15  
0.040  
0
0.51  
15  
1.02  
E
J 56 PL  
D 56 PL  
0.25 (0.010)  
M
S
T A  
M
S
T B  
0.25 (0.010)  
11.10 48-Pin Plastic DIP (Case 767)  
NOTE  
The MC68HC811E2 is the only member of the E series that is offered in a  
48-pin plastic dual in-line package.  
NOTES:  
1. DIMENSIONING AND TOLERANCING PER ANSI  
Y14.5M, 1982.  
-A-  
2. CONTROLLING DIMENSION: INCH.  
3. DIMENSION L TO CENTER OF LEAD WHEN FORMED  
PARALLEL.  
48  
1
25  
24  
4. DIMENSIONSAANDBDONOTINCLUDEMOLDFLASH.  
MAXIMUM MOLD FLASH 0.25 (0.010).  
-B-  
TIP TAPER  
INCHES  
DIM MIN MAX  
MILLIMETERS  
MIN  
61.34  
13.72  
3.94  
MAX  
62.10  
14.22  
5.08  
A
B
C
D
F
2.415  
0.540  
0.155  
0.014  
0.040  
2.445  
0.560  
0.200  
0.022  
0.060  
DETAIL X  
0.36  
1.02  
0.55  
1.52  
C
L
G
H
J
K
L
0.100 BSC  
0.070 BSC  
2.54 BSC  
1.79 BSC  
0.008  
0.115  
0.015  
0.150  
0.20  
2.92  
0.38  
3.81  
0.600 BSC  
15.24 BSC  
15  
0.51  
-T-  
K
M
N
0
×
0.020  
15  
0.040  
0
×
×
×
1.01  
SEATING  
PLANE  
M 48 PL  
N
DETAIL X  
G
F
J 48 PL  
D 32 PL  
M
S
T B  
0.25 (0.010)  
M
S
T A  
0.51 (0.020)  
M68HC11E Family Data Sheet, Rev. 5.1  
186  
Freescale Semiconductor  
Appendix A  
Development Support  
A.1 Introduction  
This section provides information on the development support offered for the E-series devices.  
A.2 M68HC11 E-Series Development Tools  
SPGMR  
Programming  
Adapter(3)  
Emulation  
Module(1) (2)  
Flex  
Cable(1) (2)  
MMDS11  
Target Head(1) (2)  
Device  
Package  
52 FN  
52 PB  
56 B  
M68EM11E20  
M68EM11E20  
M68EM11E20  
M68EM11E20  
M68EM11E20  
M68EM11E20  
M68EM11E20  
M68EM11E20  
M68CBL11C  
M68CBL11C  
M68CBL11B  
M68CBL11C  
M68CBL11C  
M68CBL11C  
M68CBL11B  
M68CBL11C  
M68TC11E20FN52  
M68TC11E20PB52  
M68TC11E20B56  
M68TC11E20FU64  
M68TC11E20FN52  
M68TC11E20FU64  
M68TB11E20P48  
M68TC11E20FN52  
M68PA11E20FN52  
M68PA11E20PB52  
M68PA11E20B56  
M68PA11E20FU64  
M68PA11E20FN52  
M68PA11E20FU64  
M68PA11A8P48  
MC68HC11E9  
MC68HC711E9  
64 FU  
52 FN  
64 FU  
48 P  
MC68HC11E20  
MC68HC711E20  
MC68HC811E2  
52 FN  
M68PA11E20FN52  
1. Each MMDS11 system consists of a system console (M68MMDS11), an emulation module, a flex cable, and a target head.  
2. A complete EVS consists of a platform board (M68HC11PFB), an emulation module, a flex cable, and a target head.  
3. Each SPGMR system consists of a universal serial programmer (M68SPGMR11) and a programming adapter. It can be  
used alone or in conjunction with the MMDS11.  
A.3 EVS — Evaluation System  
The EVS is an economical tool for designing, debugging, and evaluating target systems based on the  
M68HC11. EVS features include:  
Monitor/debugger firmware  
One-line assembler/disassembler  
Host computer download capability  
Dual memory maps:  
64-Kbyte monitor map that includes 16 Kbytes of monitor EPROM  
M68HC11 E-series user map that includes 64 Kbytes of emulation RAM  
MCU extension input/output (I/O) port for single-chip, expanded, and special-test operation modes  
RS-232C terminal and host I/O ports  
Logic analyzer connector  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
187  
Development Support  
A.4 Modular Development System (MMDS11)  
The M68MMDS11 modular development system (MMDS11) is an emulator system for developing  
embedded systems based on an M68HC11 microcontroller unit (MCU). The MMDS11 provides a bus  
state analyzer (BSA) and real-time memory windows. The unit's integrated development environment  
includes an editor, an assembler, user interface, and source-level debug. These features significantly  
reduce the time necessary to develop and debug an embedded MCU system. The unit's compact size  
requires a minimum of desk space.  
The MMDS11 is one component of Freescale's modular approach to MCU-based product development.  
This modular approach allows easy configuration of the MMDS11 to fit a wide range of requirements. It  
also reduces development system cost by allowing the user to purchase only the modular components  
necessary to support the particular MCU derivative.  
MMDS11 features include:  
Real-time, non-intrusive, in-circuit emulation at the MCU’s operating frequency  
Real-time bus state analyzer  
8 K x 64 real-time trace buffer  
Display of real-time trace data as raw data, disassembled instructions, raw data and  
disassembled instructions, or assembly-language source code  
Four hardware triggers for commencing trace and to provide breakpoints  
Nine triggering modes  
As many as 8190 pre- or post-trigger points for trace data  
16 general-purpose logic clips, four of which can be used to trigger the bus state analyzer  
sequencer  
16-bit time tag or an optional 24-bit time tag that reduces the logic clips traced from 16 to eight  
Four data breakpoints (hardware breakpoints)  
Hardware instruction breakpoints over either the 64-Kbyte M68HC11 memory map or over a  
1-Mbyte bank switched memory map  
32 real-time variables, nine of which can be displayed in the variables window. These variables  
may be read or written while the MCU is running  
32 bytes of real-time memory can be displayed in the memory window. This memory may be read  
or written while the MCU is running  
64 Kbytes of fast emulation memory (SRAM)  
Current-limited target input/output connections  
Six software-selectable oscillator clock sources: five internally generated frequencies and an  
external frequency via a bus analyzer logic clip  
Command and response logging to MS-DOS® disk files to save session history  
SCRIPT command for automatic execution of a sequence of MMDS11 commands  
Assembly or C-language source-level debugging with global variable viewing  
Host/emulator communications speeds as high as 57,600 baud for quick program loading  
® MS-DOS is a registered trademark of Microsoft Corporation.  
M68HC11E Family Data Sheet, Rev. 5.1  
188  
Freescale Semiconductor  
SPGMR11 — Serial Programmer for M68HC11 MCUs  
Extensive on-line MCU information via the CHIPINFO command. View memory map, vectors,  
register, and pinout information pertaining to the device being emulated  
Host software supports:  
An editor  
An assembler and user interface  
Source-level debug  
Bus state analysis  
IBM® mouse  
A.5 SPGMR11 — Serial Programmer for M68HC11 MCUs  
The SPGMR11 is a modular EPROM/EEPROM programming tool for all M68HC11 devices. The  
programmer features interchangeable adapters that allow programming of various M68HC11 package  
types.  
Programmer features include:  
Programs M68HC11 Family devices that contain an EPROM or EEPROM array.  
Can be operated as a stand-alone programmer connected to a host computer or connected  
between a host computer and the M68HC11 modular development system (MMDS11) station  
module  
Uses plug-in programming adapters to accommodate a variety of MCU devices and packages  
On-board programming voltage circuit eliminates the need for an external 12-volt supply.  
Includes programming software and a user’s manual  
Includes a +5-volt power cable and a DB9 to DB25 connector adapter  
® IBM is a registered trademark145 of International Business Machines Corporation.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
189  
Development Support  
M68HC11E Family Data Sheet, Rev. 5.1  
190  
Freescale Semiconductor  
Appendix B  
EVBU Schematic  
Refer to Figure B-1 for a schematic diagram of the M68HC11EVBU Universal Evaluation Board. This  
diagram is included for reference only.  
M68HC11E Family Data Sheet, Rev. 5.1  
Freescale Semiconductor  
191  
MCU [2 . . . 52]  
V
V
V
V
CC  
CC  
CC  
CC  
1
1
1
V
CC  
RN1D  
47 K  
RN1C  
47 K  
RN1B  
47 K  
R1  
47 K  
U3  
42 MCU42  
41 MCU41  
40 MCU40  
39 MCU39  
38 MCU38  
37 MCU37  
36 MCU36  
35 MCU35  
25  
PB0/A8  
PB1/A9  
5
4
3
V
DD  
MCU18 (XIRQ)  
MCU 34 34  
MCU 33 33  
MCU 32 32  
MCU 31 31  
MCU 30 30  
MCU 29 29  
MCU 28 28  
MCU 27 27  
C8  
0.1  
C7  
1 µF  
PA0/IC3  
PA1/IC2  
PA2/IC1  
PA3/OC5  
PA4/OC4  
PA5/OC3  
PA6/OC2  
PA7/OC1  
PB2/A10  
PB3/A11  
PB4/A12  
PB5/A13  
PB6/A14  
PB7/A15  
1
µF  
J7  
2
MCU31 (PA3/OC5)  
MCU19 (IRQ)  
9
MCU9  
PC0/AD0  
PC1/AD1  
PC2/AD2  
PC3/AD3  
PC4/AD4  
PC5/AD5  
PC6/AD6  
PC7/AD7  
10 MCU10  
11 MCU11  
12 MCU12  
13 MCU13  
14 MCU14  
15 MCU15  
16 MCU16  
V
CC  
MCU 20 20  
MCU 21 21  
MCU 22 22  
MCU 23 23  
MCU 24 24  
MCU 25 25  
PD0/RXD  
PD1/TXD  
PD2/MISO  
PD3/MOSI  
PD4/SCK  
PD5/SS  
J2  
R4  
47 K  
1
3
MCU43 (PE0)  
2
MCU3 (MODA/LIR)  
MCU2 (MODB/V  
MCU 43 43  
MCU 45 45  
MCU 47 47  
MCU 49 49  
MCU 44 44  
MCU 46 46  
MCU 48 48  
MCU 50 50  
)
5
6
4
MCU5  
MCU6  
MCU4  
PE0  
PE1  
PE2  
PE3  
PE4  
PE5  
PE6  
PE7  
STBY  
E
STRB/R/W  
STRA/AS  
RESET  
IRQ  
XIRQ  
MODA/LIR  
V
CC  
J6  
J5  
2
1
2
17 MCU17  
19 MCU19  
18 MCU18  
MCU8  
MCU7  
2
2
1
1
J3  
J4  
R3  
1 K  
3
2
MCU3  
MCU2  
1
MODB/V  
STBY  
MCU52 (V  
)
MCU 52 52  
MCU 51 51  
1
RH  
NOTE 1  
P2  
CONNECTOR DB25  
7
V
RH  
EXTAL  
XTAL  
V
13  
25  
12  
24  
11  
23  
10  
22  
9
RL  
C9  
0.1 µF  
8
V
SS  
R2  
10 M  
MC68HC11E9FN  
GND  
X1  
8 MHz  
USER’S TERMINAL OR PC  
NOTE 2  
V
V
CC  
CC  
MASTER RESET  
C5  
27 pF  
C6  
27 pF  
1
6
1
V
V
CC  
CC  
21  
8
20  
DCD  
DTR  
RN1E  
47 K  
RN1A  
47 K  
NOTE 1  
J9  
C14  
U2  
C12  
10  
20 V  
µ
F
2
2
7
19  
INPUT  
+
U4  
MCU17 (RESET)  
MCU21 (PD1/TXD)  
MCU20 (PD0/RXD)  
2
1
1
1
2
+
RESET  
17  
20  
18  
1
V
3
DSR  
6
18  
5
DD  
C1+  
C1–  
C2+  
C2–  
GND  
J8  
+
C13  
4
V
C10  
SS  
MC34064P  
+
SW1  
3
17  
4
16  
3
15  
2
CTS  
1
6
5
8
15  
16  
13  
14  
11  
12  
19  
TX1  
RX1  
DI1  
DD1  
DI2  
DD2  
DI3  
J15  
NOTE 1  
TXD  
RXD  
2
TX2  
RX2  
TX3  
RX3  
GND  
7
10  
9
V
CC  
NOTE 1  
14  
NC  
DD3  
V
1
2
V
CC  
CC  
MC145407  
C11  
0.1 µF  
Notes:  
1. Default cut traces installed from factory on bottom of the board.  
2. X1 is shipped as a ceramic resonator with built-in capacitors. Holes are provided for a crystal and two capacitors.  
Figure B-1. EVBU Schematic Diagram  
AN1060  
Rev. 1.1, 07/2005  
Freescale Semiconductor  
Application Note  
M68HC11 Bootstrap Mode  
By Jim Sibigtroth  
Mike Rhoades  
John Langan  
Austin, Texas  
Introduction  
The M68HC11 Family of MCUs (microcontroller units) has a bootstrap mode that allows a user-defined  
program to be loaded into the internal random-access memory (RAM) by way of the serial  
communications interface (SCI); the M68HC11 then executes this loaded program. The loaded program  
can do anything a normal user program can do as well as anything a factory test program can do because  
protected control bits are accessible in bootstrap mode. Although the bootstrap mode is a single-chip  
mode of operation, expanded mode resources are accessible because the mode control bits can be  
changed while operating in the bootstrap mode.  
This application note explains the operation and application of the M68HC11 bootstrap mode. Although  
basic concepts associated with this mode are quite simple, the more subtle implications of these functions  
require careful consideration. Useful applications of this mode are overlooked due to an incomplete  
understanding of bootstrap mode. Also, common problems associated with bootstrap mode could be  
avoided by a more complete understanding of its operation and implications.  
Topics discussed in this application note include:  
Basic operation of the M68HC11 bootstrap mode  
General discussion of bootstrap mode uses  
Detailed explanation of on-chip bootstrap logic  
Detailed explanation of bootstrap firmware  
Bootstrap firmware vs. EEPROM security  
Incorporating the bootstrap mode into a system  
Driving bootstrap mode from another M68HC11  
Driving bootstrap mode from a personal computer  
Common bootstrap mode problems  
Variations for specific versions of M68HC11  
Commented listings for selected M68HC11 bootstrap ROMs  
© Freescale Semiconductor, Inc., 2005. All rights reserved.  
Basic Bootstrap Mode  
Basic Bootstrap Mode  
This section describes only basic functions of the bootstrap mode. Other functions of the bootstrap mode  
are described in detail in the remainder of this application note.  
When an M68HC11 is reset in bootstrap mode, the reset vector is fetched from a small internal read-only  
memory (ROM) called the bootstrap ROM or boot ROM. The firmware program in this boot ROM then  
controls the bootloading process, in this manner:  
First, the on-chip SCI (serial communications interface) is initialized. The first character received  
($FF) determines which of two possible baud rates should be used for the remaining characters in  
the download operation.  
Next, a binary program is received by the SCI system and is stored in RAM.  
Finally, a jump instruction is executed to pass control from the bootloader firmware to the user’s  
loaded program.  
Bootstrap mode is useful both at the component level and after the MCU has been embedded into a  
finished user system.  
At the component level, Freescale uses bootstrap mode to control a monitored burn-in program for the  
on-chip electrically erasable programmable read-only memory (EEPROM). Units to be tested are loaded  
into special circuit boards that each hold many MCUS. These boards are then placed in burn-in ovens.  
Driver boards outside the ovens download an EEPROM exercise and diagnostic program to all MCUs in  
parallel. The MCUs under test independently exercise their internal EEPROM and monitor programming  
and erase operations. This technique could be utilized by an end user to load program information into  
the EPROM or EEPROM of an M68HC11 before it is installed into an end product. As in the burn-in setup,  
many M68HC11s can be gang programmed in parallel. This technique can also be used to program the  
EPROM of finished products after final assembly.  
Freescale also uses bootstrap mode for programming target devices on the M68HC11 evaluation  
modules (EVM). Because bootstrap mode is a privileged mode like special test, the EEPROM-based  
configuration register (CONFIG) can be programmed using bootstrap mode on the EVM.  
The greatest benefits from bootstrap mode are realized by designing the finished system so that bootstrap  
mode can be used after final assembly. The finished system need not be a single-chip mode application  
for the bootstrap mode to be useful because the expansion bus can be enabled after resetting the MCU  
in bootstrap mode. Allowing this capability requires almost no hardware or design cost and the addition  
of this capability is invisible in the end product until it is needed.  
The ability to control the embedded processor through downloaded programs is achieved without the  
disassembly and chip-swapping usually associated with such control. This mode provides an easy way  
to load non-volatile memories such as EEPROM with calibration tables or to program the application  
firmware into a one-time programmable (OTP) MCU after final assembly.  
Another powerful use of bootstrap mode in a finished assembly is for final test. Short programs can be  
downloaded to check parts of the system, including components and circuitry external to the embedded  
MCU. If any problems appear during product development, diagnostic programs can be downloaded to  
find the problems, and corrected routines can be downloaded and checked before incorporating them into  
the main application program.  
M68HC11 Bootstrap Mode, Rev. 1.1  
194  
Freescale Semiconductor  
Bootstrap Mode Logic  
Bootstrap mode can also be used to interactively calibrate critical analog sensors. Since this calibration  
is done in the final assembled system, it can compensate for any errors in discrete interface circuitry and  
cabling between the sensor and the analog inputs to the MCU. Note that this calibration routine is a  
downloaded program that does not take up space in the normal application program.  
Bootstrap Mode Logic  
In the M68HC11 MCUs, very little logic is dedicated to the bootstrap mode. Consequently, this mode adds  
almost no extra cost to the MCU system. The biggest piece of circuitry for bootstrap mode is the small  
boot ROM. This ROM is 192 bytes in the original MC68HC11A8, but some of the newest members of the  
M68HC11 Family, such as the MC68HC711K4, have as much as 448 bytes to accommodate added  
features. Normally, this boot ROM is present in the memory map only when the MCU is reset in bootstrap  
mode to prevent interference with the user’s normal memory space. The enable for this ROM is controlled  
by the read boot ROM (RBOOT) control bit in the highest priority interrupt (HPRIO) register. The RBOOT  
bit can be written by software whenever the MCU is in special test or special bootstrap modes; when the  
MCU is in normal modes, RBOOT reverts to 0 and becomes a read-only bit. All other logic in the MCU  
would be present whether or not there was a bootstrap mode.  
Figure 1 shows the composite memory map of the MC68HC711E9 in its four basic modes of operation,  
including bootstrap mode. The active mode is determined by the mode A (MDA) and special mode  
(SMOD) control bits in the HPRIO control register. These control bits are in turn controlled by the state of  
the mode A (MODA) and mode B (MODB) pins during reset. Table 1 shows the relationship between the  
state of these pins during reset, the selected mode, and the state of the MDA, SMOD, and RBOOT control  
bits. Refer to the composite memory map and information in Table 1 for the following discussion.  
The MDA control bit is determined by the state of the MODA pin as the MCU leaves reset. MDA selects  
between single-chip and expanded operating modes. When MDA is 0, a single-chip mode is selected,  
either normal single-chip mode or special bootstrap mode. When MDA is 1, an expanded mode is  
selected, either normal expanded mode or special test mode.  
The SMOD control bit is determined by the inverted state of the MODB pin as the MCU leaves reset.  
SMOD controls whether a normal mode or a special mode is selected. When SMOD is 0, one of the two  
normal modes is selected, either normal single-chip mode or normal expanded mode. When SMOD is 1,  
one of the two special modes is selected, either special bootstrap mode or special test mode. When either  
special mode is in effect (SMOD = 1), certain privileges are in effect, for instance, the ability to write to the  
mode control bits and fetching the reset and interrupt vectors from $BFxx rather than $FFxx.  
Table 1. Mode Selection Summary  
Input Pins  
Control Bits in HPRIO  
Mode Selected  
MODB  
MODA  
RBOOT  
SMOD  
MDA  
1
0
0
0
0
0
0
1
Normal single chip  
Normal expanded  
Special bootstrap  
Special test  
0
0
1
0
0
0
1
1
0
1
0
1
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
195  
Boot ROM Firmware  
The alternate vector locations are achieved by simply driving address bit A14 low during all vector fetches  
if SMOD = 1. For special test mode, the alternate vector locations assure that the reset vector can be  
fetched from external memory space so the test system can control MCU operation. In special bootstrap  
mode, the small boot ROM is enabled in the memory map by RBOOT = 1 so the reset vector will be  
fetched from this ROM and the bootloader firmware will control MCU operation.  
RBOOT is reset to 1 in bootstrap mode to enable the small boot ROM. In the other three modes, RBOOT  
is reset to 0 to keep the boot ROM out of the memory map. While in special test mode, SMOD = 1, which  
allows the RBOOT control bit to be written to 1 by software to enable the boot ROM for testing purposes.  
Boot ROM Firmware  
The main program in the boot ROM is the bootloader, which is automatically executed as a result of  
resetting the MCU in bootstrap mode. Some newer versions of the M68HC11 Family have additional utility  
programs that can be called from a downloaded program. One utility is available to program EPROM or  
OTP versions of the M68HC11. A second utility allows the contents of memory locations to be uploaded  
to a host computer. In the MC68HC711K4 boot ROM, a section of code is used by Freescale for stress  
testing the on-chip EEPROM. These test and utility programs are similar to self-test ROM programs in  
other MCUs except that the boot ROM does not use valuable space in the normal memory map.  
Bootstrap firmware is also involved in an optional EEPROM security function on some versions of the  
M68HC11. This EEPROM security feature prevents a software pirate from seeing what is in the on-chip  
EEPROM. The secured state is invoked by programming the no security (NOSEC) EEPROM bit in the  
CONFIG register. Once this NOSEC bit is programmed to 0, the MCU will ignore the mode A pin and  
always come out of reset in normal single-chip mode or special bootstrap mode, depending on the state  
of the mode B pin. Normal single-chip mode is the usual way a secured part would be used. Special  
bootstrap mode is used to disengage the security function (only after the contents of EEPROM and RAM  
have been erased). Refer to the M68HC11 Reference Manual, Freescale document order number  
M68HC11RM/AD, for additional information on the security mode and complete listings of the boot ROMs  
that support the EEPROM security functions.  
Automatic Selection of Baud Rate  
The bootloader program in the MC68HC711E9 accommodates either of two baud rates.  
The higher of these baud rates (7812 baud at a 2-MHz E-clock rate) is used in systems that operate  
from a binary frequency crystal such as 223 Hz (8.389 MHz). At this crystal frequency, the baud  
rate is 8192 baud, which was used extensively in automotive applications.  
The second baud rate available to the M68HC11 bootloader is 1200 baud at a 2-MHz E-clock rate.  
Some of the newest versions of the M68HC11, including the MC68HC11F1 and MC68HC117K4,  
accommodate other baud rates using the same differentiation technique explained here. Refer to  
the reference numbers in square brackets in Figure 2 during the following explanation.  
NOTE  
Software can change some aspects of the memory map after reset.  
M68HC11 Bootstrap Mode, Rev. 1.1  
196  
Freescale Semiconductor  
Automatic Selection of Baud Rate  
Figure 2 shows how the bootloader program differentiates between the default baud rate (7812 baud at  
a 2-MHz E-clock rate) and the alternate baud rate (1200 baud at a 2-MHz E-clock rate). The host  
computer sends an initial $FF character, which is used by the bootloader to determine the baud rate that  
will be used for the downloading operation. The top half of Figure 2 shows normal reception of $FF.  
Receive data samples at [1] detect the falling edge of the start bit and then verify the start bit by taking a  
sample at the center of the start bit time. Samples are then taken at the middle of each bit time [2] to  
reconstruct the value of the received character (all 1s in this case). A sample is then taken at the middle  
of the stop bit time as a framing check (a 1 is expected) [3]. Unless another character immediately follows  
this $FF character, the receive data line will idle in the high state as shown at [4].  
The bottom half of Figure 2 shows how the receiver will incorrectly receive the $FF character that is sent  
from the host at 1200 baud. Because the receiver is set to 7812 baud, the receive data samples are taken  
at the same times as in the upper half of Figure 2. The start bit at 1200 baud [5] is 6.5 times as long as  
the start bit at 7812 baud [6].  
$0000  
(MAY BE REMAPPED  
TO ANY 4K BOUNDARY)  
512-BYTE  
RAM  
$01FF  
EXTERNAL  
EXTERNAL  
$1000  
$103F  
(MAY BE REMAPPED  
TO ANY 4K BOUNDARY)  
64-BYTE  
REGISTER  
BLOCK  
EXTERNAL  
EXTERNAL  
(MAY BE DISABLED  
BY AN EEPROM BIT)  
512-BYTE  
EEPROM  
$B600  
$B7FF  
$BFC0  
BOOT  
ROM  
SPECIAL  
MODE  
VECTORS  
EXTERNAL  
EXTERNAL  
$BF00  
$BFC0  
$BFFF  
$BFFF  
(MAY BE DISABLED  
BY AN EEPROM BIT)  
$D000  
12K USER  
EPROM  
(or OTP)  
$FFC0  
NORMAL  
MODE  
VECTORS  
$FFC0  
$FFFF  
$FFFF  
SINGLE  
CHIP  
EXPANDED  
MULTIPLEXED  
SPECIAL  
BOOTSTRAP  
SPECIAL  
TEST  
MODA = 0  
MODB = 1  
MODA = 1  
MODB = 1  
MODA = 0  
MODB = 0  
MODA = 1  
MODB = 0  
NOTE: Software can change some aspects of the memory map after reset.  
Figure 1. MC68HC711E9 Composite Memory Map  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
197  
Main Bootloader Program  
[6]  
[4]  
$FF CHARACTER  
@ 7812 BAUD  
START BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 STOP Tx DATA LINE IDLES HIGH  
Rx DATA SAMPLES  
[3]  
S
0
1
1
1
1
1
1
1
1
1
[2]  
[1]  
$FF  
[5]  
$FF CHARACTER  
@ 1200 BAUD  
START  
BIT 0  
BIT 1  
Rx DATA SAMPLES  
( FOR 7812 BAUD )  
[8]  
0
[12]  
[11]  
S
0
[7]  
0
0
0
0
?
1
1
1
[9]  
$C0  
or $E0 [10]  
Figure 2. Automatic Detection of Baud Rate  
Samples taken at [7] detect the failing edge of the start bit and verify it is a logic 0. Samples taken at the  
middle of what the receiver interprets as the first five bit times [8] detect logic 0s. The sample taken at the  
middle of what the receiver interprets as bit 5 [9] may detect either a 0 or a 1 because the receive data  
has a rising transition at about this time. The samples for bits 6 and 7 detect 1s, causing the receiver to  
think the received character was $C0 or $E0 [10] at 7812 baud instead of the $FF which was sent at 1200  
baud. The stop bit sample detects a 1 as expected [11], but this detection is actually in the middle of bit  
0 of the 1200 baud $FF character. The SCI receiver is not confused by the rest of the 1200 baud $FF  
character because the receive data line is high [12] just as it would be for the idle condition. If a character  
other than $FF is sent as the first character, an SCI receive error could result.  
Main Bootloader Program  
Figure 3 is a flowchart of the main bootloader program in the MC68HC711E9. This bootloader  
demonstrates the most important features of the bootloaders used on all M68HC11 Family members. For  
complete listings of other M68HC11 versions, refer to Listing 3. MC68HC711E9 Bootloader ROM at the  
end of this application note, and to Appendix B of the M68HC11 Reference Manual, Freescale document  
order number M68HC11RM/AD.  
The reset vector in the boot ROM points to the start [1] of this program. The initialization block [2]  
establishes starting conditions and sets up the SCI and port D. The stack pointer is set because there are  
push and pull instructions in the bootloader program. The X index register is pointed at the start of the  
register block ($1000) so indexed addressing can be used. Indexed addressing takes one less byte of  
ROM space than extended instructions, and bit manipulation instructions are not available in extended  
addressing forms. The port D wire-OR mode (DWOM) bit in the serial peripheral interface control register  
(SPCR) is set to configure port D for wired-OR operation to minimize potential conflicts with external  
systems that use the PD1/TxD pin as an input. The baud rate for the SCI is initially set to 7812 baud at a  
2-MHz E-clock rate but can automatically switch to 1200 baud based on the first character received. The  
SCI receiver and transmitter are enabled. The receiver is required by the bootloading process, and the  
transmitter is used to transmit data back to the host computer for optional verification. The last item in the  
initialization is to set an intercharacter delay constant used to terminate the download when the host  
computer stops sending data to the MC68HC711E9. This delay constant is stored in the timer output  
compare 1 (TOC1) register, but the on-chip timer is not used in the bootloader program. This example  
M68HC11 Bootstrap Mode, Rev. 1.1  
198  
Freescale Semiconductor  
Main Bootloader Program  
illustrates the extreme measures used in the bootloader firmware to minimize memory usage. However,  
such measures are not usually considered good programming technique because they are misleading to  
someone trying to understand the program or use it as an example.  
After initialization, a break character is transmitted [3] by the SCI. By connecting the TxD pin to the RxD  
pin (with a pullup because of port D wired-OR mode), this break will be received as a $00 character and  
cause an immediate jump [4] to the start of the on-chip EEPROM ($B600 in the MC68HC711E9). This  
feature is useful to pass control to a program in EEPROM essentially from reset. Refer to Common  
Bootstrap Mode Problems before using this feature.  
If the first character is received as $FF, the baud rate is assumed to be the default rate (7812 baud at a  
2-MHz E-clock rate). If $FF was sent at 1200 baud by the host, the SCI will receive the character as $E0  
or $C0 because of the baud rate mismatch, and the bootloader will switch to 1200 baud [5] for the rest of  
the download operation. When the baud rate is switched to 1200 baud, the delay constant used to monitor  
the intercharacter delay also must be changed to reflect the new character time.  
At [6], the Y index register is initialized to $0000 to point to the start of on-chip RAM. The index register Y  
is used to keep track of where the next received data byte will be stored in RAM. The main loop for loading  
begins at [7].  
The number of data bytes in the downloaded program can be any number between 0 and 512 bytes (the  
size of on-chip RAM). This procedure is called "variable-length download" and is accomplished by ending  
the download sequence when an idle time of at least four character times occurs after the last character  
to be downloaded. In M68HC11 Family members which have 256 bytes of RAM, the download length is  
fixed at exactly 256 bytes plus the leading $FF character.  
The intercharacter delay counter is started [8] by loading the delay constant from TOC1 into the X index  
register. The 19-E-cycle wait loop is executed repeatedly until either a character is received [9] or the  
allowed intercharacter delay time expires [10]. For 7812 baud, the delay constant is 10,241 E cycles (539  
x 19 E cycles per loop). Four character times at 7812 baud is 10,240 E cycles (baud prescale of 4 x baud  
divider of 4 x 16 internal SCI clocks/bit time x 10 bit times/character x 4 character times). The delay from  
reset to the initial $FF character is not critical since the delay counter is not started until after the first  
character ($FF) is received.  
To terminate the bootloading sequence and jump to the start of RAM without downloading any data to the  
on-chip RAM, simply send $FF and nothing else. This feature is similar to the jump to EEPROM at [4]  
except the $FF causes a jump to the start of RAM. This procedure requires that the RAM has been loaded  
with a valid program since it would make no sense to jump to a location in uninitialized memory.  
After receiving a character, the downloaded byte is stored in RAM [11]. The data is transmitted back to  
the host [12] as an indication that the download is progressing normally. At [13], the RAM pointer is  
incremented to the next RAM address. If the RAM pointer has not passed the end of RAM, the main  
download loop (from [7] to [14]) is repeated.  
When all data has been downloaded, the bootloader goes to [16] because of an intercharacter delay  
timeout [10] or because the entire 512-byte RAM has been filled [15]. At [16], the X and Y index registers  
are set up for calling the PROGRAM utility routine, which saves the user from having to do this in a  
downloaded program. The PROGRAM utility is fully explained in EPROM Programming Utility. The final  
step of the bootloader program is to jump to the start of RAM [17], which starts the user’s downloaded  
program.  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
199  
Main Bootloader Program  
FROM RESET  
IN BOOT MODE  
[1]  
START  
[2]  
INITIALIZATION:  
SP = TOP OF RAM ($01FF)  
X = START OF REGS ($1000)  
SPCR = $20 (SET DWOM BIT)  
BAUD = $A2 (÷ 4; ÷ 4) (7812.5 BAUD @ 2 MHz)  
SCCR2 = $C0 (Tx & Rx ON)  
TOC1 = DELAY CONSTANT (539 = 4 SCI CHARACTER TIMES)  
[3]  
SEND BREAK  
NO  
RECEIVED FIRST CHAR YET ?  
YES  
[4]  
JUMP TO START  
OF EEPROM ($B600)  
YES  
FIRST CHAR = $00 ?  
NO  
NOTZERO  
NOTE THAT A BREAK  
CHARACTER IS ALSO  
RECEIVED AS $00  
YES  
FIRST CHAR = $FF ?  
NO  
[5]  
SWITCH TO SLOWER SCI RATE...  
BAUD = $33 (÷13; ÷ 8) (1200 BAUD @ 2 MHz)  
CHANGE DELAY CONSTANT...  
TOC1 = 3504 (4 SCI CHARACTER TIMES)  
BAUDOK  
[6]  
POINT TO START OF RAM ( Y = $0000 )  
[7]  
WAIT  
[8]  
INITIALIZE TIMEOUT COUNT  
WTLOOP  
[9]  
YES  
RECEIVE DATA READY ?  
NO  
LOOP =  
19  
CYCLES  
DECREMENT TIMEOUT COUNT  
NO  
TIMED OUT YET ?  
[10]  
YES  
[11]  
STORE RECEIVED DATA TO RAM ( ,Y )  
TRANSMIT (ECHO) FOR VERIFY  
POINT AT NEXT RAM LOCATION  
[12]  
[13]  
[14]  
NO  
PAST END OF RAM ?  
YES  
[15]  
STAR  
SET UP FOR PROGRAM UTILITY:  
X = PROGRAMMING TIME CONSTANT  
Y = START OF EPROM  
[16]  
JUMP TO START  
OF RAM ($0000)  
[17]  
Figure 3. MC68HC711E9 Bootloader Flowchart  
M68HC11 Bootstrap Mode, Rev. 1.1  
200  
Freescale Semiconductor  
UPLOAD Utility  
UPLOAD Utility  
The UPLOAD utility subroutine transfers data from the MCU to a host computer system over the SCI serial  
data link.  
NOTE  
Only EPROM versions of the M68HC11 include this utility.  
Verification of EPROM contents is one example of how the UPLOAD utility could be used. Before calling  
this program, the Y index register is loaded (by user firmware) with the address of the first data byte to be  
uploaded. If a baud rate other than the current SCI baud rate is to be used for the upload process, the  
user’s firmware must also write to the baud register. The UPLOAD program sends successive bytes of  
data out the SCI transmitter until a reset is issued (the upload loop is infinite).  
For a complete commented listing example of the UPLOAD utility, refer to Listing 3. MC68HC711E9  
Bootloader ROM.  
EPROM Programming Utility  
The EPROM programming utility is one way of programming data into the internal EPROM of the  
MC68HC711E9 MCU. An external 12-V programming power supply is required to program on-chip  
EPROM. The simplest way to use this utility program is to bootload a 3-byte program consisting of a single  
jump instruction to the start of the PROGRAM utility program ($BF00). The bootloader program sets the  
X and Y index registers to default values before jumping to the downloaded program (see [16] at the  
bottom of Figure 3). When the host computer sees the $FF character, data to be programmed into the  
EPROM is sent, starting with the character for location $D000. After the last byte to be programmed is  
sent to the MC68HC711E9 and the corresponding verification data is returned to the host, the  
programming operation is terminated by resetting the MCU.  
The number of bytes to be programmed, the first address to be programmed, and the programming time  
can be controlled by the user if values other than the default values are desired.  
To understand the detailed operation of the EPROM programming utility, refer to Figure 4 during the  
following discussion. Figure 4 is composed of three interrelated parts. The upper-left portion shows the  
flowchart of the PROGRAM utility running in the boot ROM of the MCU. The upper-right portion shows  
the flowchart for the user-supplied driver program running in the host computer. The lower portion of  
Figure 4 is a timing sequence showing the relationship of operations between the MCU and the host  
computer. Reference numbers in the flowcharts in the upper half of Figure 4 have matching numbers in  
the lower half to help the reader relate the three parts of the figure.  
The shaded area [1] refers to the software and hardware latency in the MCU leading to the transmission  
of a character (in this case, the $FF). The shaded area [2] refers to a similar latency in the host computer  
(in this case, leading to the transmission of the first data character to the MCU).  
The overall operation begins when the MCU sends the first character ($FF) to the host computer,  
indicating that it is ready for the first data character. The host computer sends the first data byte [3] and  
enters its main loop. The second data character is sent [4], and the host then waits [5] for the first verify  
byte to come back from the MCU.  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
201  
EPROM Programming Utility  
PROGRAM Utility in MCU  
Driver Program in HOST  
INITIALIZE...  
HOST NORMALLY WAITS FOR $FF  
X = PROGRAM TIME  
Y = FIRST ADDRESS  
FROM MCU BEFORE SENDING DATA  
FOR EPROM PROGRAMMING  
START  
$BF00 - PROGRAM  
START  
INDICATES READY  
TO HOST  
[8]  
[3]  
SEND $FF  
[9]  
SEND FIRST DATA BYTE  
DATA_LOOP  
WAIT1  
NO  
MORE DATA TO SEND ?  
NO  
ANY DATA RECEIVED ?  
YES  
YES  
SEND NEXT DATA [4] [6]  
PROGRAM BYTE [10] [13]  
[5] [7]  
NO  
READ PROGRAMMED DATA  
AND SEND TO VERIFY  
VERIFY DATA RECEIVED ?  
YES  
[11] [14]  
NO  
VERIFY DATA CORRECT ?  
YES  
INDICATE ERROR  
POINT TO NEXT LOCATION  
TO BE PROGRAMMED  
[12] [15]  
YES  
MORE TO VERIFY ?  
NO  
PROGRAM CONTINUES  
AS LONG AS DATA  
IS RECEIVED  
DONE  
VERIFY DATA TO HOST  
(SAME AS MCU Tx DATA)  
$FF  
[3]  
V1  
[6]  
V2  
D3  
V3  
V4  
D5  
[4]  
HOST SENDING  
DATA FOR  
MCU EPROM  
[5]  
[1]  
[7]  
D4  
MCU RECEIVE DATA (FROM HOST)  
EPROM PROGRAMMING  
D1  
D2  
[2]  
[10]  
[13]  
MC68HC711E9  
EXECUTING  
"PROGRAM" LOOP  
P1  
P2  
[12]  
V1  
P3  
P4  
[14]  
[9]  
[11]  
[15]  
[8]  
MCU TRANSMIT DATA (VERIFY)  
$FF  
V2  
V3  
V4  
Figure 4. Host and MCU Activity during EPROM PROGRAM Utility  
M68HC11 Bootstrap Mode, Rev. 1.1  
202  
Freescale Semiconductor  
Allowing for Bootstrap Mode  
After the MCU sends $FF [8], it enters the WAIT1 loop [9] and waits for the first data character from the  
host. When this character is received [10], the MCU programs it into the address pointed to by the Y index  
register. When the programming time delay is over, the MCU reads the programmed data, transmits it to  
the host for verification [11], and returns to the top of the WAIT1 loop to wait for the next data character  
[12]. Because the host previously sent the second data character, it is already waiting in the SCI receiver  
of the MCU. Steps [13], [14], and [15] correspond to the second pass through the WAIT1 loop.  
Back in the host, the first verify character is received, and the third data character is sent [6]. The host  
then waits for the second verify character [7] to come back from the MCU. The sequence continues as  
long as the host continues to send data to the MCU. Since the WAIT1 loop in the PROGRAM utility is an  
indefinite loop, reset is used to end the process in the MCU after the host has finished sending data to be  
programmed.  
Allowing for Bootstrap Mode  
Since bootstrap mode requires few connections to the MCU, it is easy to design systems that  
accommodate bootstrap mode.  
Bootstrap mode is useful for diagnosing or repairing systems that have failed due to changes in the  
CONFIG register or failures of the expansion address/data buses, (rendering programs in external  
memory useless). Bootstrap mode can also be used to load information into the EPROM or EEPROM of  
an M68HC11 after final assembly of a module. Bootstrap mode is also useful for performing system  
checks and calibration routines. The following paragraphs explain system requirements for use of  
bootstrap mode in a product.  
Mode Select Pins  
It must be possible to force the MODA and MODB pins to logic 0, which implies that these two pins should  
be pulled up to VDD through resistors rather than being tied directly to VDD. If mode pins are connected  
directly to VDD, it is not possible to force a mode other than the one the MCU is hard wired for. It is also  
good practice to use pulldown resistors to VSS rather than connecting mode pins directly to VSS because  
it is sometimes a useful debug aid to attempt reset in modes other than the one the system was primarily  
designed for. Physically, this requirement sometimes calls for the addition of a test point or a wire  
connected to one or both mode pins. Mode selection only uses the mode pins while RESET is active.  
RESET  
It must be possible to initiate a reset while the mode select pins are held low. In systems where there is  
no provision for manual reset, it is usually possible to generate a reset by turning power off and back on.  
RxD Pin  
It must be possible to drive the PD0/RxD pin with serial data from a host computer (or another MCU). In  
many systems, this pin is already used for SCI communications; thus no changes are required.  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
203  
Allowing for Bootstrap Mode  
In systems where the PD0/RxD pin is normally used as a general-purpose output, a serial signal from the  
host can be connected to the pin without resulting in output driver conflicts. It may be important to consider  
what the existing logic will do with the SCI serial data instead of the signals that would have been  
produced by the PD0 pin. In systems where the PD0 pin is used normally as a general-purpose input, the  
driver circuit that drives the PD0 pin must be designed so that the serial data can override this driver, or  
the driver must be disconnected during the bootstrap download. A simple series resistor between the  
driver and the PD0 pin solves this problem as shown in Figure 5. The serial data from the host computer  
can then be connected to the PD0/RxD pin, and the series resistor will prevent direct conflict between the  
host driver and the normal PD0 driver.  
CONNECTED ONLY DURING  
BOOTLOADING  
FROM  
HOST  
SYSTEM  
RS232  
LEVEL  
SHIFTER  
MC68HC11  
EXISTING  
CONTROL  
SIGNAL  
RxD/PD0  
(BEING USED  
AS INPUT)  
SERIES  
RESISTOR  
EXISTING  
DRIVER  
Figure 5. Preventing Driver Conflict  
TxD Pin  
The bootloader program uses the PD1/TxD pin to send verification data back to the host computer. To  
minimize the possibility of conflicts with circuitry connected to this pin, port D is configured for wire-OR  
mode by the bootloader program during initialization. Since the wire-OR configuration prevents the pin  
from driving active high levels, a pullup resistor to VDD is needed if the TxD signal is used.  
In systems where the PD1/TxD pin is normally used as a general-purpose output, there are no output  
driver conflicts. It may be important to consider what the existing logic will do with the SCI serial data  
instead of the signals that would have been produced by the PD1 pin.  
In systems where the PD1 pin is normally used as a general-purpose input, the driver circuit that drives  
the PD1 pin must be designed so that the PD1/TxD pin driver in the MCU can override this driver. A simple  
series resistor between the driver and the PD1 pin can solve this problem. The TxD pin can then be  
configured as an output, and the series resistor will prevent direct conflict between the internal TxD driver  
and the external driver connected to PD1 through the series resistor.  
Other  
The bootloader firmware sets the DWOM control bit, which configures all port D pins for wire-OR  
operation. During the bootloading process, all port D pins except the PD1/TxD pin are configured as  
high-impedance inputs. Any port D pin that normally is used as an output should have a pullup resistor so  
it does not float during the bootloading process.  
M68HC11 Bootstrap Mode, Rev. 1.1  
204  
Freescale Semiconductor  
Driving Boot Mode from Another M68HC11  
Driving Boot Mode from Another M68HC11  
A second M68HC11 system can easily act as the host to drive bootstrap loading of an M68HC11 MCU.  
This method is used to examine and program non-volatile memories in target M68HC11s in Freescale  
EVMs. The following hardware and software example will demonstrate this and other bootstrap mode  
features.  
The schematic in Figure 6 shows the circuitry for a simple EPROM duplicator for the MC68HC711E9. The  
circuitry is built in the wire-wrap area of an M68HC11EVBU evaluation board to simplify construction. The  
schematic shows only the important portions of the EVBU circuitry to avoid confusion. To see the  
complete EVBU schematic, refer to the M68HC11EVBU Universal Evaluation Board User’s Manual,  
Freescale document order number M68HC11EVBU/D.  
The default configuration of the EVBU must be changed to make the appropriate connections to the  
circuitry in the wire-wrap area and to configure the master MCU for bootstrap mode. A fabricated jumper  
must be installed at J6 to connect the XTAL output of the master MCU to the wire-wrap connector P5,  
which has been wired to the EXTAL input of the target MCU. Cut traces that short across J8 and J9 must  
be cut on the solder side of the printed circuit board to disconnect the normal SCI connections to the  
RS232 level translator (U4) of the EVBU. The J8 and J9 connections can be restored easily at a later time  
by installing fabricated jumpers on the component side of the board. A fabricated jumper must be installed  
across J3 to configure the master MCU for bootstrap mode.  
One MC68HC711E9 is first programmed by other means with a desired 12-Kbyte program in its EPROM  
and a small duplicator program in its EEPROM. Alternately, the ROM program in an MC68HC11E9 can  
be copied into the EPROM of a target MC68HC711E9 by programming only the duplicator program into  
the EEPROM of the master MC68HC11E9. The master MCU is installed in the EVBU at socket U3. A  
blank MC68HC711E9 to be programmed is placed in the socket in the wire-wrap area of the EVBU (U6).  
With the VPP power switch off, power is applied to the EVBU system. As power is applied to the EVBU,  
the master MCU (U3) comes out of reset in bootstrap mode. Target MCU (U6) is held in reset by the PB7  
output of master MCU (U3). The PB7 output of U3 is forced to 0 when U3 is reset. The master MCU will  
later release the reset signal to the target MCU under software control. The RxD and TxD pins of the target  
MCU (U6) are high-impedance inputs while U6 is in reset so they will not affect the TxD and RxD signals  
of the master MCU (U3) while U3 is coming out of reset. Since the target MCU is being held in reset with  
MODA and MODB at 0, it is configured for the PROG EPROM emulation mode, and PB7 is the output  
enable signal for the EPROM data I/O (input/output) pins. Pullup resistor R7 causes the port D pins,  
including RxD and TxD, to remain in the high-impedance state so they do not interfere with the RxD and  
TxD pins of the master MCU as it comes out of reset.  
As U3 leaves reset, its mode pins select bootstrap mode so the bootloader firmware begins executing. A  
break is sent out the TxD pin of U3. Pullup resistor R10 and resistor R9 cause the break character to be  
seen at the RxD pin of U3. The bootloader performs a jump to the start of EEPROM in the master MCU  
(U3) and starts executing the duplicator program. This sequence demonstrates how to use bootstrap  
mode to pass control to the start of EEPROM after reset.  
The complete listing for the duplicator program in the EEPROM of the master MCU is provided in  
Listing 1. MCU-to-MCU Duplicator Program.  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
205  
Driving Boot Mode from Another M68HC11  
COM +12.25V  
M68HC11EVBU  
PREWIRED AREA WIRE-WRAP AREA  
ON  
V
R11  
100  
P4  
P5  
PP  
+
OFF  
C18  
R14  
15K  
S2  
20 µF  
50  
50  
50  
PE7  
R15  
10K  
MASTER  
MCU  
U3  
MC68HC711E9  
18  
17  
XIRQ/V  
RESET  
PPE  
R8  
35  
35  
35  
PB7  
3.3K  
V
DD  
D5  
41  
42  
41  
42  
41  
42  
26  
1
PB1  
PB0  
V
DD  
RED  
C17  
0.1 µF  
R12 1K  
R13 1K  
D6  
V
SS  
GREEN  
TARGET  
MCU  
U6  
J6  
J3  
8
2
8
8
7
XTAL  
EXTAL  
V
V
DD  
DD  
MODB  
35  
20  
PB7  
RxD  
R7  
10K  
R10  
15K  
21  
20  
21  
20  
21  
20  
TxD  
RxD  
R9  
[1]  
10K  
21  
TxD  
[2]  
3
2
MODA  
MODB  
J8  
J9  
TO/FROM  
RS232 LEVEL  
TRANSLATOR  
U4  
Figure 6. MCU-to-MCU EPROM Duplicator Schematic  
M68HC11 Bootstrap Mode, Rev. 1.1  
206  
Freescale Semiconductor  
Driving Boot Mode from Another M68HC11  
The duplicator program in EEPROM clears the DWOM control bit to change port D (thus, TxD) of U3 to  
normal driven outputs. This configuration will prevent interference due to R9 when TxD from the target  
MCU (U6) becomes active. Series resistor R9 demonstrates how TxD of U3 can drive RxD of U3[1] and  
later TxD of U6 can drive RxD of U3 without a destructive conflict between the TxD output buffers.  
As the target MCU (U6) leaves reset, its mode pins select bootstrap mode so the bootloader firmware  
begins executing. A break is sent out the TxD pin of U6. At this time, the TxD pin of U3 is at a driven high  
so R9 acts as a pullup resistor for TxD of the target MCU (U6). The break character sent from U6 is  
received by U3 so the duplicator program that is running in the EEPROM of the master MCU knows that  
the target MCU is ready to accept a bootloaded program.  
The master MCU sends a leading $FF character to set the baud rate in the target MCU. Next, the master  
MCU passes a 3-instruction program to the target MCU and pauses so the bootstrap program in the target  
MCU will stop the loading process and jump to the start of the downloaded program. This sequence  
demonstrates the variable-length download feature of the MC68HC711E9 bootloader.  
The short program downloaded to the target MCU clears the DWOM bit to change its TxD pin to a normal  
driven CMOS output and jumps to the EPROM programming utility in the bootstrap ROM of the target  
MCU.  
Note that the small downloaded program did not have to set up the SCI or initialize any parameters for  
the EPROM programming process. The bootstrap software that ran prior to the loaded program left the  
SCI turned on and configured in a way that was compatible with the SCI in the master MCU (the duplicator  
program in the master MCU also did not have to set up the SCI for the same reason). The programming  
time and starting address for EPROM programming in the target MCU were also set to default values by  
the bootloader software before jumping to the start of the downloaded program.  
Before the EPROM in the target MCU can be programmed, the VPP power supply must be available at  
the XIRQ/VPPE pin of the target MCU. The duplicator program running in the master MCU monitors this  
voltage (for presence or absence, not level) at PE7 through resistor divider R14–Rl5. The PE7 input was  
chosen because the internal circuitry for port E pins can tolerate voltages slightly higher than VDD  
;
therefore, resistors R14 and R15 are less critical. No data to be programmed is passed to the target MCU  
until the master MCU senses that VPP has been stable for about 200 ms.  
When VPP is ready, the master MCU turns on the red LED (light-emitting diode) and begins passing data  
to the target MCU. EPROM Programming Utility explains the activity as data is sent from the master MCU  
to the target MCU and programmed into the EPROM of the target. The master MCU in the EVBU  
corresponds to the HOST in the programming utility description and the "PROGRAM utility in MCU" is  
running in the bootstrap ROM of the target MCU.  
Each byte of data sent to the target is programmed and then the programmed location is read and sent  
back to the master for verification. If any byte fails, the red and green LEDs are turned off, and the  
programming operation is aborted. If the entire 12 Kbytes are programmed and verified successfully, the  
red LED is turned off, and the green LED is turned on to indicate success. The programming of all 12  
Kbytes takes about 30 seconds.  
After a programming operation, the VPP switch (S2) should be turned off before the EVBU power is turned  
off.  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
207  
Listing 1. MCU-to-MCU Duplicator Program  
V
CUT TRACE  
AS SHOWN  
DD  
RN1D  
47K  
TO MCU  
XIRQ/VPPE  
PIN  
1
3
1
7
+
P4-18  
P5-18  
47  
J7  
48  
46  
44  
9
8
10  
1
FROM OC5 PIN  
OF MCU  
2
45  
41  
15  
REMOVE J7  
JUMPER  
38  
13  
25  
28 19  
27  
J14  
20  
34  
35  
1
21  
33  
TO  
MC68HC68T1  
BE SURE NO  
JUMPER IS  
ON J14  
Figure 7. Isolating EVBU XIRQ Pin  
Listing 1. MCU-to-MCU Duplicator Program  
1
2
**************************************************  
* 68HC711E9 Duplicator Program for AN1060  
3
**************************************************  
4
5
*****  
6
* Equates - All reg addrs except INIT are 2-digit  
7
*
for direct addressing  
8
*****  
INIT  
SPCR  
PORTB  
9 103D  
10 0028  
11 0004  
12  
EQU  
EQU  
EQU  
$103D  
$28  
$04  
RAM, Reg mapping  
DWOM in bit-5  
Red LED = bit-1, Grn = bit-0  
* Reset of prog socket = bit-7  
13 0080  
14 0002  
15 0001  
16 000A  
17 002E  
18  
RESET  
RED  
GREEN  
PORTE  
SCSR  
EQU  
EQU  
EQU  
EQU  
EQU  
%10000000  
%00000010  
%00000001  
$0A  
Vpp Sense in bit-7, 1=ON  
SCI status register  
$2E  
* TDRE, TC, RDRF, IDLE; OR, NF, FE, -  
19 0080  
20 0020  
21 002F  
22 BF00  
23 D000  
24  
TDRE  
RDRF  
SCDR  
PROGRAM  
EPSTRT  
EQU  
EQU  
EQU  
EQU  
EQU  
%10000000  
%00100000  
$2F  
$BF00  
$D000  
SCI data register  
EPROM prog utility in boot ROM  
Starting address of EPROM  
25 B600  
26  
ORG  
$B600  
Start of EEPROM  
M68HC11 Bootstrap Mode, Rev. 1.1  
208  
Freescale Semiconductor  
Listing 1. MCU-to-MCU Duplicator Program  
**************************************************  
27  
28  
*
29 B600 7F103D  
30 B603 8604  
31 B605 9728  
32 B607 8680  
33 B609 9704  
BEGIN  
CLR  
INIT  
#$04  
SPCR  
#RESET  
PORTB  
Moves Registers to $0000-3F  
Pattern for DWOM off, no SPI  
Turns off DWOM in EVBU MCU  
LDAA  
STAA  
LDAA  
STAA  
Release reset to target MCU  
34 B60B 132E20FC WT4BRK  
35 B60F 86FF  
36 B611 972F  
BRCLR SCSR RDRF WT4BRK Loop till char received  
LDAA  
STAA  
LDX  
#$FF  
SCDR  
#BLPROG  
SEND1  
Leading char for bootload ...  
to target MCU  
Point at program for target  
Bootload to target  
37 B613 CEB675  
38 B616 8D53  
BLLOOP  
BSR  
39 B618 8CB67D  
40 B61B 26F9  
CPX  
BNE  
#ENDBPR  
BLLOOP  
Past end ?  
Continue till all sent  
41  
*****  
42  
43  
44  
* Delay for about 4 char times to allow boot related  
* SCI communications to finish before clearing  
* Rx related flags  
45 B61D CE06A7  
46 B620 09  
47 B621 26FD  
48 B623 962E  
49 B625 962F  
50  
LDX  
DEX  
BNE  
LDAA  
LDAA  
#1703  
# of 6 cyc loops  
[3]  
[3] Total loop time = 6 cyc  
Read status (RDRF will be set)  
Read SCI data reg to clear RDRF  
DLYLP  
DLYLP  
SCSR  
SCDR  
*****  
51  
52  
* Now wait for character from target to indicate it's ready for  
* data to be programmed into EPROM  
53 B627 132E20FC WT4FF  
54 B62B 962F  
55 B62D CED000  
BRCLR SCSR RDRF WT4FF Wait for RDRF  
LDAA  
LDX  
SCDR  
#EPSTRT  
Clear RDRF, don't need data  
Point at start of EPROM  
56  
* Handle turn-on of Vpp  
57 B630 18CE523D WT4VPP  
58 B634 150402  
LDY  
#21053  
PORTB RED  
PORTE  
WT4VPP  
PORTB RED  
Delay counter (about 200ms)  
Turn off RED LED  
[3] Wait for Vpp to be ON  
[3] Vpp sense is on port E MSB  
[6] Turn on RED LED  
BCLR  
LDAA  
BPL  
BSET  
DEY  
59 B637 960A  
60 B639 2AF5  
61 B63B 140402  
62 B63E 1809  
63 B640 26F5  
64  
DLYLP2  
[4]  
BNE  
DLYLP2  
[3] Total loop time = 19 cyc  
* Vpp has been stable for 200ms  
65  
66 B642 18CED000  
67 B646 8D23  
68 B648 8C0000  
69 B64B 2702  
70 B64D 8D1C  
71 B64F 132E20FC VERF  
72 B653 962F  
73 B655 18A100  
74 B658 2705  
75 B65A 150403  
76 B65D 2007  
77 B65F  
LDY  
BSR  
CPX  
BEQ  
BSR  
#EPSTRT  
SEND1  
#0  
VERF  
SEND1  
X=Tx pointer, Y=verify pointer  
Send first data to target  
X points at $0000 after last  
Skip send if no more  
Send another data char  
Wait for Rx ready  
Get char and clr RDRF  
Does char verify ?  
Skip error if OK  
DATALP  
BRCLR SCSR RDRF VERF  
LDAA  
CMPA  
BEQ  
BCLR  
BRA  
SCDR  
0,Y  
VERFOK  
PORTB (RED+GREEN) Turn off LEDs  
DUNPRG  
Done (programming failed)  
78 B65F 1808  
79 B661 26E5  
80 B663  
VERFOK  
INY  
BNE  
Advance verify pointer  
Continue till all done  
DATALP  
81 B663 140401  
BSET  
PORTB GREEN  
Grn LED ON  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
209  
Listing 1. MCU-to-MCU Duplicator Program  
82 B666  
83 B666 150482  
84 B669 20FE  
DUNPRG  
BCLR  
BRA  
PORTB (RESET+RED) Red OFF, apply reset  
* Done so just hang  
85 B66B  
86  
87  
**************************************************  
* Subroutine to get & send an SCI char. Also  
88  
89  
*
advances pointer (X).  
**************************************************  
SEND1 LDAA 0,X Get a character  
BRCLR SCSR TDRE TRDYLP Wait for TDRE  
90 B66B A600  
91 B66D 132E80FC TRDYLP  
92 B671 972F  
93 B673 08  
STAA  
INX  
SCDR  
Send character  
Advance pointer  
** Return **  
94 B674 39  
RTS  
95  
96  
97  
**************************************************  
* Program to be bootloaded to target '711E9  
98  
**************************************************  
99 B675 8604  
100 B677 B71028  
101  
BLPROG  
LDAA  
STAA  
#$04  
$1028  
Pattern for DWOM off, no SPI  
Turns off DWOM in target MCU  
* NOTE: Can't use direct addressing in target MCU because  
102  
*
regs are located at $1000.  
103 B67A 7EBF00  
104 B67D  
JMP  
EQU  
PROGRAM  
*
Jumps to EPROM prog routine  
ENDBPR  
Symbol Table:  
Symbol Name  
Value Def.# Line Number Cross Reference  
BEGIN  
BLLOOP  
BLPROG  
DATALP  
DLYLP  
DLYLP2  
DUNPRG  
ENDBPR  
EPSTRT  
GREEN  
INIT  
B600 *00029  
B616 *00038 00040  
B675 *00099 00037  
B648 *00068 00079  
B620 *00046 00047  
B637 *00059 00063  
B666 *00083 00076  
B67D *00104 00039  
D000 *00023 00055 00066  
0001 *00015 00075 00081  
103D *00009 00029  
PORTB  
PORTE  
PROGRAM  
RDRF  
RED  
RESET  
SCDR  
SCSR  
SEND1  
SPCR  
0004 *00011 00033 00058 00061 00075 00081 00083  
000A *00016 00059  
BF00 *00022 00103  
0020 *00020 00034 00053 00071  
0002 *00014 00058 00061 00075 00083  
0080 *00013 00032 00083  
002F *00021 00036 00049 00054 00072 00092  
002E *00017 00034 00048 00053 00071 00091  
B66B *00090 00038 00067 00070  
0028 *00010 00031  
TDRE  
0080 *00019 00091  
TRDYLP  
VERF  
VERFOK  
WT4BRK  
WT4FF  
WT4VPP  
B66D *00091 00091  
B64F *00071 00069 00071  
B65F *00078 00074  
B60B *00034 00034  
B627 *00053 00053  
B630 *00057 00060  
M68HC11 Bootstrap Mode, Rev. 1.1  
210  
Freescale Semiconductor  
Driving Boot Mode from a Personal Computer  
Errors: None  
Labels: 28  
Last Program Address: $B67C  
Last Storage Address: $0000  
Program Bytes: $007D 125  
Storage Bytes: $0000  
0
Driving Boot Mode from a Personal Computer  
In this example, a personal computer is used as the host to drive the bootloader of an MC68HC711E9.  
An M68HC11 EVBU is used for the target MC68HC711E9. A large program is transferred from the  
personal computer into the EPROM of the target MC68HC711E9.  
Hardware  
Figure 7 shows a small modification to the EVBU to accommodate the 12-volt (nominal) EPROM  
programming voltage. The XIRQ pin is connected to a pullup resistor, two jumpers, and the 60-pin  
connectors, P4 and P5. The object of the modification is to isolate the XIRQ pin and then connect it to the  
programming power supply. Carefully cut the trace on the solder side of the EVBU as indicated in Figure  
7. This disconnects the pullup resistor RN1 D from XIRQ but leaves P4–18, P5–18, and jumpers J7 and  
J14 connected so the EVBU can still be used for other purposes after programming is done. Remove any  
fabricated jumpers from J7 and J14. The EVBU normally has a jumper at J7 to support the trace function  
Figure 8 shows a small circuit that is added to the wire-wrap area of the EVBU. The 3-terminal jumper  
allows the XIRQ line to be connected to either the programming power supply or to a substitute pullup  
resistor for XIRQ. The 100-ohm resistor is a current limiter to protect the 12-volt input of the MCU. The  
resistor and LED connected to P5 pin 9 (port C bit 0) is an optional indicator that lights when programming  
is complete.  
Software  
BASIC was chosen as the programming language due to its readability and availability in parallel versions  
on both the IBM® PC and the Macintosh®. The program demonstrates several programming techniques  
for use with an M68HC11 and is not necessarily intended to be a finished, commercial program. For  
example, there is little error checking, and the user interface is elementary. A complete listing of the  
BASIC program is included in Listing 2. BASIC Program for Personal Computer with moderate comments.  
The following paragraphs include a more detailed discussion of the program as it pertains to  
communicating with and programming the target MC68HC711E9. Lines 25–45 initialize and define the  
variables and array used in the program. Changes to this section would allow for other programs to be  
downloaded.  
® IBM is a registered trademark of International Business Machines.  
® Macintosh is a registered trademark of Apple Computers, Inc.  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
211  
Driving Boot Mode from a Personal Computer  
V
DD  
47K  
NORMAL EVBU  
OPERATION  
TO P5-18  
(XIRQ/V  
)
100  
PPE  
PROGRAM  
EPROM  
+12.25 V  
+
JUMPER  
20 µF  
PROGRAMMING  
POWER  
COMMON  
PC0  
P5-9  
1K  
LED  
Figure 8. PC-to-MCU Programming Circuit  
Lines 50–95 read in the small bootloader from DATA statements at the end of the listing. The source code  
for this bootloader is presented in the DATA statements. The bootloaded code makes port C bit 0 low,  
initializes the X and Y registers for use by the EPROM programming utility routine contained in the boot  
ROM, and then jumps to that routine. The hexadecimal values read in from the DATA statements are  
converted to binary values by a subroutine. The binary values are then saved as one string  
(BOOTCODE$).  
The next long section of code (lines 97–1250) reads in the S records from an external disk file (in this  
case, BUF34.S19), converts them to integer, and saves them in an array. The techniques used in this  
section show how to convert ASCII S records to binary form that can be sent (bootloaded) to an  
M68HC11.  
This S-record translator only looks for the S1 records that contain the actual object code. All other  
S-record types are ignored.  
When an S1 record is found (lines 1000–1024), the next two characters form the hex byte giving the  
number of hex bytes to follow. This byte is converted to integer by the same subroutine that converted the  
bootloaded code from the DATA statements. This BYTECOUNT is adjusted by subtracting 3, which  
accounts for the address and checksum bytes and leaves just the number of object-code bytes in the  
record.  
Starting at line 1100, the 2-byte (4-character) starting address is converted to decimal. This address is  
the starting address for the object code bytes to follow. An index into the CODE% array is formed by  
subtracting the base address initialized at the start of the program from the starting address for this S  
record.  
A FOR-NEXT loop starting at line 1130 converts the object code bytes to decimal and saves them in the  
CODE% array. When all the object code bytes have been converted from the current S record, the  
program loops back to find the next S1 record.  
M68HC11 Bootstrap Mode, Rev. 1.1  
212  
Freescale Semiconductor  
Driving Boot Mode from a Personal Computer  
A problem arose with the BASIC programming technique used. The draft versions of this program tried  
saving the object code bytes directly as binary in a string array. This caused "Out of Memory" or "Out of  
String Space" errors on both a 2-Mbyte Macintosh and a 640-Kbyte PC. The solution was to make the  
array an integer array and perform the integer-to-binary conversion on each byte as it is sent to the target  
part.  
The one compromise made to accommodate both Macintosh and PC versions of BASIC is in lines 1500  
and 1505. Use line 1500 and comment out line 1505 if the program is to be run on a Macintosh, and,  
conversely, use line 1505 and comment out line 1500 if a PC is used.  
After the COM port is opened, the code to be bootloaded is modified by adding the $FF to the start of the  
string. $FF synchronizes the bootloader in the MC68HC711E9 to 1200 baud. The entire string is simply  
sent to the COM port by PRINTing the string. This is possible since the string is actually queued in  
BASIC’s COM buffer, and the operating system takes care of sending the bytes out one at a time. The  
M68HC11 echoes the data received for verification. No automatic verification is provided, though the data  
is printed to the screen for manual verification.  
Once the MCU has received this bootloaded code, the bootloader automatically jumps to it. The small  
bootloaded program in turn includes a jump to the EPROM programming routine in the boot ROM.  
Refer to the previous explanation of the EPROM Programming Utility for the following discussion. The  
host system sends the first byte to be programmed through the COM port to the SCI of the MCU. The SCI  
port on the MCU buffers one byte while receiving another byte, increasing the throughput of the EPROM  
programming operation by sending the second byte while the first is being programmed.  
When the first byte has been programmed, the MCU reads the EPROM location and sends the result back  
to the host system. The host then compares what was actually programmed to what was originally sent.  
A message indicating which byte is being verified is displayed in the lower half of the screen. If there is  
an error, it is displayed at the top of the screen.  
As soon as the first byte is verified, the third byte is sent. In the meantime, the MCU has already started  
programming the second byte. This process of verifying and queueing a byte continues until the host  
finishes sending data. If the programming is completely successful, no error messages will have been  
displayed at the top of the screen. Subroutines follow the end of the program to handle some of the  
repetitive tasks. These routines are short, and the commenting in the source code should be sufficient  
explanation.  
Modifications  
This example programmed version 3.4 of the BUFFALO monitor into the EPROM of an MC68HC711E9;  
the changes to the BASIC program to download some other program are minor.  
The necessary changes are:  
1. In line 30, the length of the program to be downloaded must be assigned to the variable  
CODESIZE%.  
2. Also in line 30, the starting address of the program is assigned to the variable ADRSTART.  
3. In line 9570, the start address of the program is stored in the third and fourth items in that DATA  
statement in hexadecimal.  
4. If any changes are made to the number of bytes in the boot code in the DATA statements in lines  
9500–9580, then the new count must be set in the variable "BOOTCOUNT" in line 25.  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
213  
Driving Boot Mode from a Personal Computer  
Operation  
Configure the EVBU for boot mode operation by putting a jumper at J3. Ensure that the trace command  
jumper at J7 is not installed because this would connect the 12-V programming voltage to the OC5 output  
of the MCU.  
Connect the EVBU to its dc power supply. When it is time to program the MCU EPROM, turn on the  
12-volt programming power supply to the new circuitry in the wire-wrap area.  
Connect the EVBU serial port to the appropriate serial port on the host system. For the Macintosh, this is  
the modem port with a modem cable. For the MS-DOS® computer, it is connected to COM1 with a straight  
through or modem cable. Power up the host system and start the BASIC program. If the program has not  
been compiled, this is accomplished from within the appropriate BASIC compiler or interpreter. Power up  
the EVBU.  
Answer the prompt for filename with either a [RETURN] to accept the default shown or by typing in a new  
filename and pressing [RETURN].  
The program will inform the user that it is working on converting the file from S records to binary. This  
process will take from 30 seconds to a few minutes, depending on the computer.  
A prompt reading, "Comm port open?" will appear at the end of the file conversion. This is the last chance  
to ensure that everything is properly configured on the EVBU. Pressing [RETURN] will send the bootcode  
to the target MC68HC711E9. The program then informs the user that the bootload code is being sent to  
the target, and the results of the echoing of this code are displayed on the screen.  
Another prompt reading "Programming is ready to begin. Are you?" will appear. Turn on the 12-volt  
programming power supply and press [RETURN] to start the actual programming of the target EPROM.  
A count of the byte being verified will be updated continually on the screen as the programming  
progresses. Any failures will be flagged as they occur.  
When programming is complete, a message will be displayed as well as a prompt requesting the user to  
press [RETURN] to quit.  
Turn off the 12-volt programming power supply before turning off 5 volts to the EVBU.  
® MS-DOS is a registered trademark of Microsoft Corporation in the United States and oth175190er countries.  
M68HC11 Bootstrap Mode, Rev. 1.1  
214  
Freescale Semiconductor  
Listing 2. BASIC Program for Personal Computer  
Listing 2. BASIC Program for Personal Computer  
1 ' ***********************************************************************  
2 ' *  
3 ' *  
4 ' *  
5 ' *  
6 ' *  
7 ' *  
8 ' *  
9 ' *  
10 '*  
11 '*  
12 '*  
14 '*  
E9BUF.BAS - A PROGRAM TO DEMONSTRATE THE USE OF THE BOOT MODE  
ON THE HC11 BY PROGRAMMING AN HC711E9 WITH  
BUFFALO 3.4  
REQUIRES THAT THE S-RECORDS FOR BUFFALO (BUF34.S19)  
BE AVAILABLE IN THE SAME DIRECTORY OR FOLDER  
THIS PROGRAM HAS BEEN RUN BOTH ON A MS-DOS COMPUTER  
USING QUICKBASIC 4.5 AND ON A MACINTOSH USING  
QUICKBASIC 1.0.  
15 '************************************************************************  
25 H$ = "0123456789ABCDEF" 'STRING TO USE FOR HEX CONVERSIONS  
30 DEFINT B, I: CODESIZE% = 8192: ADRSTART= 57344!  
35 BOOTCOUNT = 25  
'NUMBER OF BYTES IN BOOT CODE  
40 DIM CODE%(CODESIZE%)  
45 BOOTCODE$ = ""  
'BUFFALO 3.4 IS 8K BYTES LONG  
'INITIALIZE BOOTCODE$ TO NULL  
49 REM ***** READ IN AND SAVE THE CODE TO BE BOOT LOADED *****  
50 FOR I = 1 TO BOOTCOUNT  
55 READ Q$  
'# OF BYTES IN BOOT CODE  
60 A$ = MID$(Q$, 1, 1)  
65 GOSUB 7000  
70 TEMP = 16 * X  
75 A$ = MID$(Q$, 2, 1)  
80 GOSUB 7000  
'CONVERTS HEX DIGIT TO DECIMAL  
'HANG ON TO UPPER DIGIT  
85 TEMP = TEMP + X  
90 BOOTCODE$ = BOOTCODE$ + CHR$(TEMP)  
95 NEXT I  
'BUILD BOOT CODE  
96 REM ***** S-RECORD CONVERSION STARTS HERE *****  
97 FILNAM$="BUF34.S19"  
'DEFAULT FILE NAME FOR S-RECORDS  
100 CLS  
105 PRINT "Filename.ext of S-record file to be downloaded (";FILNAM$;") ";  
107 INPUT Q$  
110 IF Q$<>"" THEN FILNAM$=Q$  
120 OPEN FILNAM$ FOR INPUT AS #1  
130 PRINT : PRINT "Converting "; FILNAM$; " to binary..."  
999 REM ***** SCANS FOR 'S1' RECORDS *****  
1000 GOSUB 6000  
'GET 1 CHARACTER FROM INPUT FILE  
'FLAG IS EOF FLAG FROM SUBROUTINE  
1010 IF FLAG THEN 1250  
1020 IF A$ <> "S" THEN 1000  
1022 GOSUB 6000  
1024 IF A$ <> "1" THEN 1000  
1029 REM ***** S1 RECORD FOUND, NEXT 2 HEX DIGITS ARE THE BYTE COUNT *****  
1030 GOSUB 6000  
1040 GOSUB 7000  
1050 BYTECOUNT = 16 * X  
1060 GOSUB 6000  
'RETURNS DECIMAL IN X  
'ADJUST FOR HIGH NIBBLE  
1070 GOSUB 7000  
1080 BYTECOUNT = BYTECOUNT + X  
'ADD LOW NIBBLE  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
215  
Listing 2. BASIC Program for Personal Computer  
1090 BYTECOUNT = BYTECOUNT - 3  
'ADJUST FOR ADDRESS + CHECKSUM  
1099 REM ***** NEXT 4 HEX DIGITS BECOME THE STARTING ADDRESS FOR THE DATA *****  
1100 GOSUB 6000  
1102 GOSUB 7000  
'GET FIRST NIBBLE OF ADDRESS  
'CONVERT TO DECIMAL  
1104 ADDRESS= 4096 * X  
1106 GOSUB 6000  
'GET NEXT NIBBLE  
1108 GOSUB 7000  
1110 ADDRESS= ADDRESS+ 256 * X  
1112 GOSUB 6000  
1114 GOSUB 7000  
1116 ADDRESS= ADDRESS+ 16 * X  
1118 GOSUB 6000  
1120 GOSUB 7000  
1122 ADDRESS= ADDRESS+ X  
1124 ARRAYCNT = ADDRESS-ADRSTART  
'INDEX INTO ARRAY  
1129 REM ***** CONVERT THE DATA DIGITS TO BINARY AND SAVE IN THE ARRAY *****  
1130 FOR I = 1 TO BYTECOUNT  
1140 GOSUB 6000  
1150 GOSUB 7000  
1160 Y = 16 * X  
1170 GOSUB 6000  
1180 GOSUB 7000  
1190 Y = Y + X  
'SAVE UPPER NIBBLE OF BYTE  
'ADD LOWER NIBBLE  
1200 CODE%(ARRAYCNT) = Y  
1210 ARRAYCNT = ARRAYCNT + 1  
1220 NEXT I  
'SAVE BYTE IN ARRAY  
'INCREMENT ARRAY INDEX  
1230 GOTO 1000  
1250 CLOSE 1  
1499 REM ***** DUMP BOOTLOAD CODE TO PART *****  
1500 'OPEN "R",#2,"COM1:1200,N,8,1" 'Macintosh COM statement  
1505 OPEN "COM1:1200,N,8,1,CD0,CS0,DS0,RS" FOR RANDOM AS #2 'DOS COM statement  
1510 INPUT "Comm port open"; Q$  
1512 WHILE LOC(2) >0  
1513 GOSUB 8020  
1514 WEND  
'FLUSH INPUT BUFFER  
1515 PRINT : PRINT "Sending bootload code to target part..."  
1520 A$ = CHR$(255) + BOOTCODE$ 'ADD HEX FF TO SET BAUD RATE ON TARGET HC11  
1530 GOSUB 6500  
1540 PRINT  
1550 FOR I = 1 TO BOOTCOUNT  
1560 GOSUB 8000  
'# OF BYTES IN BOOT CODE BEING ECHOED  
1564 K=ASC(B$):GOSUB 8500  
1565 PRINT "Character #"; I; " received = "; HX$  
1570 NEXT I  
1590 PRINT "Programming is ready to begin.": INPUT "Are you ready"; Q$  
1595 CLS  
1597 WHILE LOC(2) > 0  
1598 GOSUB 8020  
'FLUSH INPUT BUFFER  
1599 WEND  
1600 XMT = 0: RCV = 0  
1610 A$ = CHR$(CODE%(XMT))  
1620 GOSUB 6500  
'POINTERS TO XMIT AND RECEIVE BYTES  
'SEND FIRST BYTE  
1625 FOR I = 1 TO CODESIZE% - 1  
1630 A$ = CHR$(CODE%(I))  
1635 GOSUB 6500  
'ZERO BASED ARRAY 0 -> CODESIZE-1  
'SEND SECOND BYTE TO GET ONE IN QUEUE  
'SEND IT  
M68HC11 Bootstrap Mode, Rev. 1.1  
216  
Freescale Semiconductor  
Listing 2. BASIC Program for Personal Computer  
'GET BYTE FOR VERIFICATION  
1640 GOSUB 8000  
1650 RCV = I - 1  
1660 LOCATE 10,1:PRINT "Verifying byte #"; I; "  
1664 IF CHR$(CODE%(RCV)) = B$ THEN 1670  
1665 K=CODE%(RCV):GOSUB 8500  
"
1666 LOCATE 1,1:PRINT "Byte #"; I; "  
1668 K=ASC(B$):GOSUB 8500  
1669 PRINT " Received "; HX$;  
1670 NEXT I  
", " - Sent "; HX$;  
1680 GOSUB 8000  
'GET BYTE FOR VERIFICATION  
1690 RCV = CODESIZE% - 1  
1700 LOCATE 10,1:PRINT "Verifying byte #"; CODESIZE%; "  
1710 IF CHR$(CODE%(RCV)) = B$ THEN 1720  
1713 K=CODE(RCV):GOSUB 8500  
"
1714 LOCATE 1,1:PRINT "Byte #"; CODESIZE%; "  
1715 K=ASC(B$):GOSUB 8500  
", " - Sent "; HX$;  
1716 PRINT " Received "; HX$;  
1720 LOCATE 8, 1: PRINT : PRINT "Done!!!!"  
4900 CLOSE  
4910 INPUT "Press [RETURN] to quit...", Q$  
5000 END  
5900 '***********************************************************************  
5910 '*  
5930 '*  
SUBROUTINE TO READ IN ONE BYTE FROM A DISK FILE  
RETURNS BYTE IN A$  
5940 '***********************************************************************  
6000 FLAG = 0  
6010 IF EOF(1) THEN FLAG = 1: RETURN  
6020 A$ = INPUT$(1, #1)  
6030 RETURN  
6490 '***********************************************************************  
6492 '*  
6494 '*  
SUBROUTINE TO SEND THE STRING IN A$ OUT TO THE DEVICE  
OPENED AS FILE #2.  
6496 '***********************************************************************  
6500 PRINT #2, A$;  
6510 RETURN  
6590 '***********************************************************************  
6594 '*  
SUBROUTINE THAT CONVERTS THE HEX DIGIT IN A$ TO AN INTEGER  
6596 '***********************************************************************  
7000 X = INSTR(H$, A$)  
7010 IF X = 0 THEN FLAG = 1  
7020 X = X - 1  
7030 RETURN  
7990 '**********************************************************************  
7992 '*  
7994 '*  
7996 '*  
7998 '*  
SUBROUTINE TO READ IN ONE BYTE THROUGH THE COMM PORT OPENED  
AS FILE #2. WAITS INDEFINITELY FOR THE BYTE TO BE  
RECEIVED. SUBROUTINE WILL BE ABORTED BY ANY  
KEYBOARD INPUT. RETURNS BYTE IN B$. USES Q$.  
7999 '**********************************************************************  
8000 WHILE LOC(2) = 0 'WAIT FOR COMM PORT INPUT  
8005 Q$ = INKEY$: IF Q$ <> "" THEN 4900 'IF ANY KEY PRESSED, THEN ABORT  
8010 WEND  
8020 B$ = INPUT$(1, #2)  
8030 RETURN  
8490 '************************************************************************  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
217  
Common Bootstrap Mode Problems  
8491 '*  
8492 '*  
8493 '*  
DECIMAL TO HEX CONVERSION  
INPUT: K - INTEGER TO BE CONVERTED  
OUTPUT: HX$ - TWO CHARACTER STRING WITH HEX CONVERSION  
8494 '************************************************************************  
8500 IF K > 255 THEN HX$="Too big":GOTO 8530  
8510 HX$=MID$(H$,K\16+1,1)  
'UPPER NIBBLE  
8520 HX$=HX$+MID$(H$,(K MOD 16)+1,1) 'LOWER NIBBLE  
8530 RETURN  
9499 '******************** BOOT CODE ****************************************  
9500 DATA 86, 23  
9510 DATA B7, 10, 02  
9520 DATA 86, FE  
9530 DATA B7, 10, 03  
9540 DATA C6, FF  
9550 DATA F7, 10, 07  
9560 DATA CE, 0F, A0  
9570 DATA 18, CE, E0, 00  
9580 DATA 7E, BF, 00  
'LDAA  
'STAA  
'LDAA  
'STAA  
'LDAB  
'STAB  
'LDX  
#$23  
OPT2  
#$FE  
PORTC  
#$FF  
DDRC  
#4000  
make port C wire or  
light 1 LED on port C bit 0  
make port C outputs  
2msec at 2MHz  
'LDY  
'JMP  
#$E000 Start of BUFFALO 3.4  
$BF00 EPROM routine start address  
9590 '***********************************************************************  
Common Bootstrap Mode Problems  
It is not unusual for a user to encounter problems with bootstrap mode because it is new to many users.  
By knowing some of the common difficulties, the user can avoid them or at least recognize and quickly  
correct them.  
Reset Conditions vs. Conditions as Bootloaded Program Starts  
It is common to confuse the reset state of systems and control bits with the state of these systems and  
control bits when a bootloaded program in RAM starts.  
Between these times, the bootloader program is executed, which changes the states of some systems  
and control bits:  
The SCI system is initialized and turned on (Rx and Tx).  
The SCI system has control of the PD0 and PD1 pins.  
Port D outputs are configured for wire-OR operation.  
The stack pointer is initialized to the top of RAM.  
Time has passed (two or more SCI character times).  
Timer has advanced from its reset count value.  
Users also forget that bootstrap mode is a special mode. Thus, privileged control bits are accessible, and  
write protection for some registers is not in effect. The bootstrap ROM is in the memory map. The DISR  
bit in the TEST1 control register is set, which disables resets from the COP and clock monitor systems.  
Since bootstrap is a special mode, these conditions can be changed by software. The bus can even be  
switched from single-chip mode to expanded mode to gain access to external memories and peripherals.  
M68HC11 Bootstrap Mode, Rev. 1.1  
218  
Freescale Semiconductor  
Table 2. Summary of Boot-ROM-Related Features  
BOOT  
ROM  
Revision  
(@$BFD1)  
Mask Set  
I.D.  
MCU Type  
Default  
RAM  
Location  
PROGRAM(3)  
and UPLOAD(4) Notes  
Utility  
Download  
Length  
JMP on  
JMP  
MCU Part  
I.D.  
Security  
BRK or $00(1) to RAM(2)  
(@$BFD2,3) (@$BFD4,5)  
(5)  
MC68HC11A0  
MC68HC11A1  
MC68HC11A8  
MC68SEC11A8  
Mask set #  
Mask set #  
Mask set #  
Mask set #  
256  
256  
256  
256  
$B600  
$B600  
$B600  
$B600  
$0000  
$0000  
$0000  
$0000  
$0000–FF  
$0000–FF  
$0000–FF  
$0000–FF  
(5)  
(5)  
(5)  
Yes  
(6)  
(6)  
MC68HC11D3  
MC68HC711D3  
$00  
$42(B)  
ROM I.D. #  
$0000  
$11D3  
$71D3  
0–192  
0–192  
$F000–ROM  
$F000–EPROM  
$0040–FF  
$0040–FF  
Yes  
(5)  
(5)  
MC68HC811E2  
MC68SEC811E2  
$0000  
$E2E2  
$E25C  
Yes  
256  
256  
$B600  
$B600  
$0000  
$0000  
$0000–FF  
$0000–FF  
MC68HC11E0  
MC68HC11E1  
MC68HC11E9  
MC68SEC11E9  
ROM I.D. #  
ROM I.D. #  
ROM I.D. #  
ROM I.D. #  
$E9E9  
$E9E9  
$E9E9  
$E95C  
0–512  
0–512  
0–512  
0–512  
$B600  
$B600  
$B600  
$B600  
$0000–1FF  
$0000–1FF  
$0000–1FF  
$0000–1FF  
(5)  
(5)  
(5)  
(5)  
Yes  
MC68HC711E9  
MC68HC11F1  
$41(A)  
$42(B)  
$0000  
$0000  
$71E9  
$F1F1  
0–512  
$B600  
$FE00  
$0000–1FF  
$0000–3FF  
Yes  
(6), (7)  
0–1024  
(6), (8)  
(6), (8)  
MC68HC11K4  
MC68HC711K4  
$30(0)  
$42(B)  
ROM I.D. #  
$0000  
$044B  
$744B  
0–768  
0–768  
$0D80  
$0D80  
$0080–37F  
$0080–37F  
Yes  
NOTES:  
1. By sending $00 or a break as the first SCI character after reset in bootstrap mode, a jump (JMP) is executed to the address in this table rather than  
doing a download. Unless otherwise noted, this address is the start of EEPROM. Tying RxD to TxD and using a pullup resistor from TxD to VDD will  
cause the SCI to see a break as the first received character.  
2. If $55 is received as the first character after reset in bootstrap mode, a jump (JMP) is executed to the start of on-chip RAM rather than doing a  
download. This $55 character must be sent at the default baud rate (7812 baud @ E = 2 MHz). For devices with variable-length download, the same  
effect can be achieved by sending $FF and no other SCI characters. After four SCI character times, the download terminates, and a jump (JMP) to  
the start of RAM is executed.  
The jump to RAM feature is only useful if the RAM was previously loaded with a meaningful program.  
3. A callable utility subroutine is included in the bootstrap ROM of the indicated versions to program bytes of on-chip EPROM with data received via the  
SCI.  
4. A callable utility subroutine is included in the bootstrap ROM of the indicated versions to upload contents of on-chip memory to a host computer via  
the SCI.  
5. The complete listing for this bootstrap ROM may be found in the M68HC11 Reference Manual, Freescale document order number M68HC11RM/AD.  
6. The complete listing for this bootstrap ROM is available in the freeware area of the Freescale Web site.  
7. Due to the extra program space needed for EEPROM security on this device, there are no pseudo-vectors for SCI, SPI, PAIF, PAOVF, TOF, OC5F,  
or OC4F interrupts.  
8. This bootloader extends the automatic software detection of baud rates to include 9600 baud at 2-MHz E-clock rate.  
Common Bootstrap Mode Problems  
Connecting RxD to VSS Does Not Cause the SCI to Receive a Break  
To force an immediate jump to the start of EEPROM, the bootstrap firmware looks for the first received  
character to be $00 (or break). The data reception logic in the SCI looks for a 1-to-0 transition on the RxD  
pin to synchronize to the beginning of a receive character. If the RxD pin is tied to ground, no 1-to-0  
transition occurs. The SCI transmitter sends a break character when the bootloader firmware starts, and  
this break character can be fed back to the RxD pin to cause the jump to EEPROM. Since TxD is  
configured as an open-drain output, a pullup resistor is required.  
$FF Character Is Required before Loading into RAM  
The initial character (usually $FF) that sets the download baud rate is often forgotten.  
Original M68HC11 Versions Required Exactly 256 Bytes to be Downloaded to RAM  
Even users that know about the 256 bytes of download data sometimes forget the initial $FF that makes  
the total number of bytes required for the entire download operation equal to 256 + 1 or 257 bytes.  
Variable-Length Download  
When on-chip RAM surpassed 256 bytes, the time required to serially load this many characters became  
more significant. The variable-length download feature allows shorter programs to be loaded without  
sacrificing compatibility with earlier fixed-length download versions of the bootloader. The end of a  
download is indicated by an idle RxD line for at least four character times. If a personal computer is being  
used to send the download data to the MCU, there can be problems keeping characters close enough  
together to avoid tripping the end-of-download detect mechanism. Using 1200 as the baud rate rather  
than the faster default rate may help this problem.  
Assemblers often produce S-record encoded programs which must be converted to binary before  
bootloading them to the MCU. The process of reading S-record data from a file and translating it to binary  
can be slow, depending on the personal computer and the programming language used for the  
translation. One strategy that can be used to overcome this problem is to translate the file into binary and  
store it into a RAM array before starting the download process. Data can then be read and downloaded  
without the translation or file-read delays.  
The end-of-download mechanism goes into effect when the initial $FF is received to set the baud rate.  
Any amount of time may pass between reset and when the $FF is sent to start the download process.  
EPROM/OTP Versions of M68HC11 Have an EPROM Emulation Mode  
The conditions that configure the MCU for EPROM emulation mode are essentially the same as those for  
resetting the MCU in bootstrap mode. While RESET is low and mode select pins are configured for  
bootstrap mode (low), the MCU is configured for EPROM emulation mode.  
The port pins that are used for EPROM data I/O lines may be inputs or outputs, depending on the pin that  
is emulating the EPROM output enable pin (OE). To make these data pins appear as high-impedance  
inputs as they would on a non-EPROM part in reset, connect the PB7/(OE) pin to a pullup resistor.  
M68HC11 Bootstrap Mode, Rev. 1.1  
220  
Freescale Semiconductor  
Boot ROM Variations  
Bootloading a Program to Performa ROM Checksum  
The bootloader ROM must be turned off before performing the checksum program. To remove the boot  
ROM from the memory map, clear the RBOOT bit in the HPRIO register. This is normally a write-protected  
bit that is 0, but in bootstrap mode it is reset to 1 and can be written. If the boot ROM is not disabled, the  
checksum routine will read the contents of the boot ROM rather than the user’s mask ROM or EPROM at  
the same addresses.  
Inherent Delays Caused by Double Buffering of SCI Data  
This problem is troublesome in cases where one MCU is bootloading to another MCU.  
Because of transmitter double buffering, there may be one character in the serial shifter as a new  
character is written into the transmit data register. In cases such as downloading in which this 2-character  
pipeline is kept full, a 2-character time delay occurs between when a character is written to the transmit  
data register and when that character finishes transmitting. A little more than one more character time  
delay occurs between the target MCU receiving the character and echoing it back. If the master MCU  
waits for the echo of each downloaded character before sending the next one, the download process  
takes about twice as long as it would if transmission is treated as a separate process or if verify data is  
ignored.  
Boot ROM Variations  
Different versions of the M68HC11 have different versions of the bootstrap ROM program. Table 3  
summarizes the features of the boot ROMs in 16 members of the M68HC11 Family.  
The boot ROMs for the MC68HC11F1, the MC68HC711K4, and the MC68HC11K4 allow additional  
choices of baud rates for bootloader communications. For the three new baud rates, the first character  
used to determine the baud rate is not $FF as it was in earlier M68HC11s. The intercharacter delay that  
terminates the variable-length download is also different for these new baud rates. Table 3 shows the  
synchronization characters, delay times, and baud rates as they relate to E-clock frequency.  
Commented Boot ROM Listing  
Listing 3. MC68HC711E9 Bootloader ROM contains a complete commented listing of the boot ROM  
program in the MC68HC711E9 version of the M68HC11. Other versions can be found in Appendix B of  
the M68HC11 Reference Manual.  
Table 3. Bootloader Baud Rates  
Baud Rates at E Clock =  
Sync  
Character  
Timeout  
Delay  
2 MHz 2.1 MHz 3 MHz 3.15 MHz 4 MHz 4.2 MHz  
$FF  
$FF  
$F0  
$FD  
$FD  
4 characters  
4 characters  
7812  
1200  
8192 11,718 12,288 15,624 16,838  
1260 1800 1890 2400 2520  
4.9 characters 9600 10,080 14,400 15,120 19,200 20,160  
17.3 characters 5208  
13 characters 3906  
5461  
4096  
7812  
5859  
8192  
6144  
10,416 10,922  
7812 8192  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
221  
Listing 3. MC68HC711E9 Bootloader ROM  
Listing 3. MC68HC711E9 Bootloader ROM  
1
****************************************************  
2
3
4
5
* BOOTLOADER FIRMWARE FOR 68HC711E9 - 21 Aug 89  
****************************************************  
* Features of this bootloader are...  
*
6
7
8
9
10  
11  
* Auto baud select between 7812.5 and 1200 (8 MHz)  
* 0 - 512 byte variable length download  
* Jump to EEPROM at $B600 if 1st download byte = $00  
* PROGRAM - Utility subroutine to program EPROM  
* UPLOAD - Utility subroutine to dump memory to host  
* Mask I.D. at $BFD4 = $71E9  
12  
13  
****************************************************  
* Revision A -  
14  
*
15  
16  
17  
* Fixed bug in PROGRAM routine where the first byte  
* programmed into the EPROM was not transmitted for  
* verify.  
18  
19  
20  
* Also added to PROGRAM routine a skip of bytes  
* which were already programmed to the value desired.  
*
21  
22  
23  
24  
* This new version allows variable length download  
* by quitting reception of characters when an idle  
* of at least four character times occurs  
*
25  
****************************************************  
26  
27  
28  
* EQUATES FOR USE WITH INDEX OFFSET = $1000  
*
29 0008  
30 000E  
31 0016  
32 0023  
33  
PORTD  
TCNT  
TOC1  
EQU  
EQU  
EQU  
EQU  
$08  
$0E  
$16  
$23  
TFLG1  
* BIT EQUATES FOR TFLG1  
34 0080  
35  
OC1F  
*
EQU  
$80  
36 0028  
37 002B  
38 002D  
39 002E  
40 002F  
41 003B  
42  
SPCR  
BAUD  
SCCR2  
SCSR  
SCDAT  
PPROG  
EQU  
EQU  
EQU  
EQU  
EQU  
EQU  
$28  
$2B  
$2D  
$2E  
$2F  
$3B  
(FOR DWOM BIT)  
* BIT EQUATES FOR PPROG  
43 0020  
44 0001  
45  
ELAT  
EPGM  
*
EQU  
EQU  
$20  
$01  
46  
47  
48  
* MEMORY CONFIGURATION EQUATES  
*
49 B600  
50 B7FF  
51  
EEPMSTR EQU  
EEPMEND EQU  
*
$B600  
$B7FF  
Start of EEPROM  
End of EEPROM  
M68HC11 Bootstrap Mode, Rev. 1.1  
222  
Freescale Semiconductor  
Listing 3. MC68HC711E9 Bootloader ROM  
Start of EPROM  
52 D000  
53 FFFF  
54  
EPRMSTR EQU  
EPRMEND EQU  
*
$D000  
$FFFF  
End of EPROM  
55 0000  
56 01FF  
RAMSTR  
RAMEND  
EQU  
EQU  
$0000  
$01FF  
57  
58  
59  
* DELAY CONSTANTS  
*
60 0DB0  
61 021B  
62  
DELAYS  
DELAYF  
*
EQU  
EQU  
3504  
539  
Delay at slow baud  
Delay at fast baud  
63 1068  
64  
PROGDEL EQU  
*
4200  
2 ms programming delay  
At 2.1 MHz  
65  
66  
67 BF00  
****************************************************  
ORG $BF00  
68  
****************************************************  
69  
70  
71  
72  
73  
* Next two instructions provide a predictable place  
* to call PROGRAM and UPLOAD even if the routines  
* change size in future versions.  
*
74 BF00 7EBF13  
75 BF03  
PROGRAM JMP  
UPLOAD EQU  
PRGROUT  
*
EPROM programming utility  
Upload utility  
76  
77  
78  
79  
80  
****************************************************  
* UPLOAD - Utility subroutine to send data from  
* inside the MCU to the host via the SCI interface.  
* Prior to calling UPLOAD set baud rate, turn on SCI  
* and set Y=first address to upload.  
81  
82  
83  
84  
85  
86  
87  
* Bootloader leaves baud set, SCI enabled, and  
* Y pointing at EPROM start ($D000) so these default  
* values do not have to be changed typically.  
* Consecutive locations are sent via SCI in an  
* infinite loop. Reset stops the upload process.  
****************************************************  
88 BF03 CE1000  
89 BF06 18A600  
LDX  
LDAA  
#$1000  
0,Y  
Point to internal registers  
Read byte  
UPLOOP  
90 BF09 1F2E80FC  
91 BF0D A72F  
92 BF0F 1808  
93 BF11 20F3  
BRCLR SCSR,X $80 *  
Wait for TDRE  
Send it  
STAA  
INY  
SCDAT,X  
UPLOOP  
BRA  
Next...  
94  
95  
96  
97  
98  
99  
****************************************************  
* PROGRAM - Utility subroutine to program EPROM.  
* Prior to calling PROGRAM set baud rate, turn on SCI  
* set X=2ms prog delay constant, and set Y=first  
* address to program. SP must point to RAM.  
100  
* Bootloader leaves baud set, SCI enabled, X=4200  
* and Y pointing at EPROM start ($D000) so these  
* default values don't have to be changed typically.  
* Delay constant in X should be equivalent to 2 ms  
101  
102  
103  
104  
105  
106  
*
at 2.1 MHz X=4200; at 1 MHz X=2000.  
* An external voltage source is required for EPROM  
* programming.  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
223  
Listing 3. MC68HC711E9 Bootloader ROM  
107  
* This routine uses 2 bytes of stack space  
108  
* Routine does not return. Reset to exit.  
109  
****************************************************  
110 BF13  
PRGROUT EQU  
PSHX  
LDX  
*
111 BF13 3C  
112 BF14 CE1000  
113 BF17  
Save program delay constant  
Point to internal registers  
#$1000  
114  
* Send $FF to indicate ready for program data  
115  
116 BF17 1F2E80FC  
117 BF1B 86FF  
118 BF1D A72F  
119  
BRCLR SCSR,X $80 *  
Wait for TDRE  
LDAA  
STAA  
#$FF  
SCDAT,X  
120 BF1F  
WAIT1  
EQU  
*
121 BF1F 1F2E20FC  
122 BF23 E62F  
123 BF25 18E100  
124 BF28 271D  
125 BF2A 8620  
126 BF2C A73B  
127 BF2E 18E700  
128 BF31 8621  
129 BF33 A73B  
130 BF35 32  
131 BF36 33  
132 BF37 37  
133 BF38 36  
134 BF39 E30E  
135 BF3B ED16  
136 BF3D 8680  
137 BF3F A723  
138  
BRCLR SCSR,X $20 *  
Wait for RDRF  
Get received byte  
See if already programmed  
If so, skip prog cycle  
Put EPROM in prog mode  
LDAB  
CMPB  
BEQ  
SCDAT,X  
$0,Y  
DONEIT  
#ELAT  
PPROG,X  
0,Y  
#ELAT+EPGM  
PPROG,X  
LDAA  
STAA  
STAB  
LDAA  
STAA  
PULA  
PULB  
PSHB  
PSHA  
ADDD  
STD  
Write the data  
Turn on prog voltage  
Pull delay constant  
into D-reg  
But also keep delay  
keep delay on stack  
Delay const + present TCNT  
Schedule OC1 (2ms delay)  
TCNT,X  
TOC1,X  
#OC1F  
LDAA  
STAA  
TFLG1,X  
Clear any previous flag  
139 BF41 1F2380FC  
140 BF45 6F3B  
141  
BRCLR TFLG1,X OC1F * Wait for delay to expire  
CLR  
PPROG,X  
Turn off prog voltage  
*
142 BF47  
DONEIT  
EQU  
*
143 BF47 1F2E80FC  
144 BF4B 18A600  
145 BF4E A72F  
146 BF50 1808  
147 BF52 20CB  
148  
BRCLR SCSR,X $80 *  
Wait for TDRE  
Read from EPROM and...  
Xmit for verify  
Point at next location  
Back to top for next  
LDAA  
STAA  
INY  
$0,Y  
SCDAT,X  
BRA  
WAIT1  
* Loops indefinitely as long as more data sent.  
149  
150  
151  
****************************************************  
* Main bootloader starts here  
152  
153  
****************************************************  
* RESET vector points to here  
154  
155 BF54  
BEGIN  
EQU  
*
156 BF54 8E01FF  
157 BF57 CE1000  
158 BF5A 1C2820  
159 BF5D CCA20C  
160 BF60 A72B  
161  
LDS  
LDX  
BSET  
LDD  
STAA  
#RAMEND  
#$1000  
SPCR,X $20  
#$A20C  
BAUD,X  
Initialize stack pntr  
Point at internal regs  
Select port D wire-OR mode  
BAUD in A, SCCR2 in B  
SCPx = ÷4, SCRx = ÷4  
* Writing 1 to MSB of BAUD resets count chain  
M68HC11 Bootstrap Mode, Rev. 1.1  
224  
Freescale Semiconductor  
Listing 3. MC68HC711E9 Bootloader ROM  
Rx and Tx Enabled  
Delay for fast baud rate  
Set as default delay  
162 BF62 E72D  
163 BF64 CC021B  
164 BF67 ED16  
165  
STAB  
LDD  
STD  
SCCR2,X  
#DELAYF  
TOC1,X  
166  
* Send BREAK to signal ready for download  
BSET SCCR2,X $01 Set send break bit  
BRSET PORTD,X $01 * Wait for RxD pin to go low  
167 BF69 1C2D01  
168 BF6C 1E0801FC  
169 BF70 1D2D01  
170 BF73  
BCLR  
SCCR2,X $01  
Clear send break bit  
171 BF73 1F2E20FC  
172 BF77 A62F  
173  
BRCLR SCSR,X $20 *  
LDAA SCDAT,X  
* Data will be $00 if BREAK OR $00 received  
Wait for RDRF  
Read data  
174 BF79 2603  
175 BF7B 7EB600  
176 BF7E  
BNE  
JMP  
NOTZERO  
EEPMSTR  
*
Bypass JMP if not 0  
Jump to EEPROM if it was 0  
NOTZERO EQU  
177 BF7E 81FF  
178 BF80 2708  
179  
CMPA  
BEQ  
#$FF  
BAUDOK  
$FF will be seen as $FF  
If baud was correct  
* Or else change to ÷104 (÷13 & ÷8) 1200 @ 2MHZ  
180 BF82 1C2B33  
181 BF85 CC0DB0  
182 BF88 ED16  
183 BF8A  
184 BF8A 18CE0000  
185  
BSET  
LDD  
STD  
EQU  
LDY  
BAUD,X $33  
#DELAYS  
TOC1,X  
*
Works because $22 -> $33  
And switch to slower...  
delay constant  
BAUDOK  
#RAMSTR  
Point at start of RAM  
186 BF8E  
187 BF8E EC16  
188 BF90  
WAIT  
EQU  
LDD  
EQU  
*
TOC1,X  
*
Move delay constant to D  
WTLOOP  
189 BF90 1E2E2007  
190 BF94 8F  
191 BF95 09  
192 BF96 8F  
193 BF97 26F7  
194 BF99 200F  
195  
BRSET SCSR,X $20 NEWONE Exit loop if RDRF set  
XGDX  
DEX  
Swap delay count to X  
Decrement count  
XGDX  
BNE  
BRA  
Swap back to D  
Loop if not timed out  
Quit download on timeout  
WTLOOP  
STAR  
196 BF9B  
NEWONE  
EQU  
*
197 BF9B A62F  
198 BF9D 18A700  
199 BFA0 A72F  
200 BFA2 1808  
201 BFA4 188C0200  
202 BFA8 26E4  
203  
LDAA  
STAA  
STAA  
INY  
CPY  
BNE  
SCDAT,X  
$00,Y  
SCDAT,X  
Get received data  
Store to next RAM location  
Transmit it for handshake  
Point at next RAM location  
See if past end  
#RAMEND+1  
WAIT  
If not, Get another  
204 BFAA  
STAR  
EQU  
LDX  
LDY  
JMP  
*
205 BFAA CE1068  
206 BFAD 18CED000  
207 BFB1 7E0000  
208 BFB4  
#PROGDEL  
#EPRMSTR  
RAMSTR  
Init X with programming delay  
Init Y with EPROM start addr  
** EXIT to start of RAM **  
209  
210  
****************************************************  
* Block fill unused bytes with zeros  
211  
212 BFB4 000000000000  
000000000000  
BSZ  
$BFD1-*  
000000000000  
000000000000  
0000000000  
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
225  
Listing 3. MC68HC711E9 Bootloader ROM  
213  
214  
215  
****************************************************  
* Boot ROM revision level in ASCII  
216  
217 BFD1 41  
218  
*
(ORG  
FCC  
$BFD1)  
"A"  
****************************************************  
* Mask set I.D. ($0000 FOR EPROM PARTS)  
219  
220  
*
(ORG  
FDB  
$BFD2)  
$0000  
221 BFD2 0000  
222  
223  
****************************************************  
* '711E9 I.D. - Can be used to determine MCU type  
224  
*
(ORG  
FDB  
$BFD4)  
$71E9  
225 BFD4 71E9  
226  
227  
228  
****************************************************  
* VECTORS - point to RAM for pseudo-vector JUMPs  
229  
230 BFD6 00C4  
231 BFD8 00C7  
232 BFDA 00CA  
233 BFDC 00CD  
234 BFDE 00D0  
235 BFE0 00D3  
236 BFE2 00D6  
237 BFE4 00D9  
238 BFE6 00DC  
239 BFE8 00DF  
240 BFEA 00E2  
241 BFEC 00E5  
242 BFEE 00E8  
243 BFF0 00EB  
244 BFF2 00EE  
245 BFF4 00F1  
246 BFF6 00F4  
247 BFF8 00F7  
248 BFFA 00FA  
249 BFFC 00FD  
250 BFFE BF54  
251 C000  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
FDB  
END  
$100-60  
$100-57  
$100-54  
$100-51  
$100-48  
$100-45  
$100-42  
$100-39  
$100-36  
$100-33  
$100-30  
$100-27  
$100-24  
$100-21  
$100-18  
$100-15  
$100-12  
$100-9  
SCI  
SPI  
PULSE ACCUM INPUT EDGE  
PULSE ACCUM OVERFLOW  
TIMER OVERFLOW  
TIMER OUTPUT COMPARE 5  
TIMER OUTPUT COMPARE 4  
TIMER OUTPUT COMPARE 3  
TIMER OUTPUT COMPARE 2  
TIMER OUTPUT COMPARE 1  
TIMER INPUT CAPTURE 3  
TIMER INPUT CAPTURE 2  
TIMER INPUT CAPTURE 1  
REAL TIME INT  
IRQ  
XIRQ  
SWI  
ILLEGAL OP-CODE  
COP FAIL  
CLOCK MONITOR  
RESET  
$100-6  
$100-3  
BEGIN  
Symbol Table:  
Symbol Name  
Value Def.# Line Number Cross Reference  
BAUD  
BAUDOK  
BEGIN  
DELAYF  
DELAYS  
DONEIT  
EEPMEND  
EEPMSTR  
ELAT  
002B *00037 00160 00180  
BF8A *00183 00178  
BF54 *00155 00250  
021B *00061 00163  
0DB0 *00060 00181  
BF47 *00142 00124  
B7FF *00050  
B600 *00049 00175  
0020 *00043 00125 00128  
0001 *00044 00128  
FFFF *00053  
EPGM  
EPRMEND  
EPRMSTR  
D000 *00052 00206  
M68HC11 Bootstrap Mode, Rev. 1.1  
226  
Freescale Semiconductor  
Listing 3. MC68HC711E9 Bootloader ROM  
NEWONE  
NOTZERO  
OC1F  
BF9B *00196 00189  
BF7E *00176 00174  
0080 *00034 00136 00139  
0008 *00029 00168  
003B *00041 00126 00129 00140  
BF13 *00110 00074  
PORTD  
PPROG  
PRGROUT  
PROGDEL  
PROGRAM  
RAMEND  
RAMSTR  
SCCR2  
SCDAT  
SCSR  
1068 *00063 00205  
BF00 *00074  
01FF *00056 00156 00201  
0000 *00055 00184 00207  
002D *00038 00162 00167 00169  
002F *00040 00091 00118 00122 00145 00172 00197 00199  
002E *00039 00090 00116 00121 00143 00171 00189  
0028 *00036 00158  
SPCR  
STAR  
BFAA *00204 00194  
TCNT  
000E *00030 00134  
TFLG1  
TOC1  
UPLOAD  
UPLOOP  
WAIT  
0023 *00032 00137 00139  
0016 *00031 00135 00164 00182 00187  
BF03 *00075  
BF06 *00089 00093  
BF8E *00186 00202  
WAIT1  
WTLOOP  
BF1F *00120 00147  
BF90 *00188 00193  
Errors: None  
Labels: 35  
Last Program Address: $BFFF  
Last Storage Address: $0000  
Program Bytes: $0100 256  
Storage Bytes: $0000  
0
M68HC11 Bootstrap Mode, Rev. 1.1  
Freescale Semiconductor  
227  
Listing 3. MC68HC711E9 Bootloader ROM  
M68HC11 Bootstrap Mode, Rev. 1.1  
228  
Freescale Semiconductor  
EB184  
Rev. 0.1, 07/2005  
Freescale Semiconductor  
Engineering Bulletin  
Enabling the Security Feature  
on the MC68HC711E9 Devices  
with PCbug11 on the  
M68HC711E9PGMR  
By Edgar Saenz  
Austin, Texas  
Introduction  
The PCbug11 software, needed along with the M68HC711E9PGMR to program MC68HC711E9 devices,  
is available from the download section of the Microcontroller Worldwide Web site:  
http://www.freescale.com  
Retrieve the file pcbug342.exe (a self-extracting archive) from the MCU11 directory.  
Some Freescale evaluation board products also are shipped with PCbug11.  
NOTE  
For specific information about any of the PCbug11 commands, see the  
appropriate sections in the PCbug11 User's Manual (part number  
M68PCBUG11/D2), which is available from the Freescale Literature  
Distribution Center, as well as the Worldwide Web at  
http://www.freescale.com. The file is also on the software download system  
and is called pcbug11.pdf.  
© Freescale Semiconductor, Inc., 2005. All rights reserved.  
To Execute the Program  
To Execute the Program  
Use this step-by-step procedure to program the MC68HC711E9 device.  
Step 1  
Before applying power to the programming board, connect the M68HC711E9PGMR serial port P2  
to one of your PC COM ports with a standard 25-pin RS-232 cable. Do not use a null modem cable  
or adapter which swaps the transmit and receive signals between the connectors at each end of  
the cable.  
Place the MC68HC711E9 part in the PLCC socket on your board.  
Insert the part upside down with the notched corner pointing toward the red power LED.  
Make sure both S1 and S2 switches are turned off.  
Apply +5 volts to +5-V, +12 volts (at most +12.5 volts) to VPP, and ground to GND on your  
programmer board’s power connector, P1. The remaining TXD/PD1 and RXD/PD0 connections  
are not used in this procedure. They are for gang programming MC68HC711E9 devices, which is  
discussed in the M68HC711E9PGMR Manual. You cannot gang program with PCbug11.  
Ensure that the "remove for multi-programming" jumper, J1, below the +5-V power switch has a  
fabricated jumper installed.  
Step 2  
Apply power to the programmer board by moving the +5-V switch to the ON position. From a DOS  
command line prompt, start PCbug11this way:  
C:\PCBUG11\ > PCBUG11 –E PORT = 1 with the E9PGMR connected to COM1  
or  
C:\PCBUG11\ > PCBUG11 –E PORT = 2 with the E9PGMR connected to COM2  
PCbug11 only supports COM ports 1 and 2. If the proper connections are made and you have a  
high-quality cable, you should quickly get a PCbug11 command prompt. If you do receive a Comms fault  
error, check the cable and board connections. Most PCbug11 communications problems can be traced  
to poorly made cables or bad board connections.  
Step 3  
PCbug11 defaults to base 10 for its input parameters.  
Change this to hexadecimal by typing: CONTROL BASE HEX.  
Step 4  
Clear the block protect register (BPROT) to allow programming of the MC68HC711E9 EEPROM.  
At the PCbug11 command prompt, type: MS 1035 00.  
Enabling the Security Feature on the MC68HC711E9 Devices with PCbug11 on the M68HC711E9PGMR, Rev. 0.1  
230  
Freescale Semiconductor  
To Execute the Program  
Step 5  
The CONFIG register defaults to hexadecimal 103F on the MC68HC711E9. PCBUG11 needs adressing  
parameters to allow programming of a specific block of memory so the following parameter must be given.  
At the PCbug11 command prompt, type: EEPROM 0.  
Then type: EEPROM 103F 103F.  
Step 6  
Erase the CONFIG to allow byte programming.  
At the PCbug11 command prompt, type: EEPROM ERASE BULK 103F.  
Step 7  
You are now ready to download the program into the EEPROM and EPROM.  
At the PCbug11command prompt, type: LOADSC:\MYPROG\MYPROG.S19.  
For more details on programming the EPROM, read the engineering bulletin Programming  
MC68HC711E9 Devices with PCbug11 and the M68HC11EVB, Freescale document number EB187.  
Step 8  
You are now ready to enable the security feature on the MCHC711E9.  
At the PCbug11 command prompt type: MS 103F 05.  
Step 9  
After the programming operation is complete, verifyng the CONFIG on the MCHC711E9 is not possible  
because in bootstrap mode the default value is always forced.  
Step 10  
The part is now in secure mode and whatever code you loaded into EEPROM will be erased if you tried  
to bring the microcontroller up in either expanded mode or bootstrap mode.  
NOTE  
It is important to note that the microcontroller will work properly in secure  
mode only in single chip mode.  
NOTE  
If the part is placed in bootstrap or expanded, the code in EEPROM and  
RAM will be erased and the microcontroller cannot be reused. The security  
software will constantly read the NOSEC bit and lock the part.  
Enabling the Security Feature on the MC68HC711E9 Devices with PCbug11 on the M68HC711E9PGMR, Rev. 0.1  
Freescale Semiconductor  
231  
To Execute the Program  
Enabling the Security Feature on the MC68HC711E9 Devices with PCbug11 on the M68HC711E9PGMR, Rev. 0.1  
232  
Freescale Semiconductor  
EB188  
Rev. 0.1, 07/2005  
Freescale Semiconductor  
Engineering Bulletin  
Enabling the Security Feature  
on M68HC811E2 Devices  
with PCbug11 on the  
M68HC711E9PGMR  
By Edgar Saenz  
Austin, Texas  
Introduction  
The PCbug11 software, needed along with the M68HC711E9PGMR to program MC68HC811E2 devices,  
is available from the download section of the Microcontroller Worldwide Web site  
http://www.freescale.com  
Retrieve the file pcbug342.exe (a self-extracting archive) from the MCU11 directory.  
Some Freescale evaluation board products also are shipped with PCbug11.  
NOTE  
For specific information about any of the PCbug11 commands, see the  
appropriate sections in the PCbug11 User's Manual (part number  
M68PCBUG11/D2), which is available from the Freescale Literature  
http://www.freescale.com. The file is also on the software download system  
and is called pcbug11.pdf.  
© Freescale Semiconductor, Inc., 2005. All rights reserved.  
To Execute the Program  
To Execute the Program  
Once you have obtained PCbug11, use this step-by-step procedure.  
Step 1  
Before applying power to the programming board, connect the M68HC711E9PGMR serial port P2  
to one of your PC COM ports with a standard 25 pin RS-232 cable. Do not use a null modem cable  
or adapter which swaps the transmit and receive signals between the connectors at each end of  
the cable.  
Place your MC68HC811E2 part in the PLCC socket on your board.  
Insert the part upside down with the notched corner pointing toward the red power LED.  
Make sure both S1 and S2 switches are turned off.  
Apply +5 volts to +5 volts and ground to GND on the programmer board’s power connector, P1.  
Applying voltage to the VPP pin is not necessary.  
Step 2  
Apply power to the programmer board by moving the +5-volt switch to the ON position.  
From a DOS command line prompt, start PCbug11 this way:  
C:\PCBUG11\> PCBUG11 –A PORT = 1 when the E9PGMR connected to COM1 or  
C:\PCBUG11\> PCBUG11 –A PORT = 2 when the E9PGMR connected to COM2  
PCbug11only supports COM ports 1 and 2.  
Step 3  
PCbug11 defaults to base ten for its input parameters.  
Change this to hexadecimal by typing: CONTROL BASE HEX  
Step 4  
Clear the block protect register (BPROT) to allow programming of the MC68HC811E2 EEPROM.  
At the PCbug11 command prompt, type: MS 1035 00  
Step 5  
PCbug11 defaults to a 512-byte EEPROM array located at $B600. This must be changed since the  
EEPROM is, by default, located at $F800 on the MC68HC811E2.  
At the PCbug11 command prompt, type: EEPROM 0  
Then type: EEPROM F800 FFFF  
Then type: EEPROM 103F 103F  
This assumes you have not relocated the EEPROM by previously reprogramming the upper 4 bits of the  
CONFIG register. But if you have done this and your S records reside in an address range other than  
$F800 to $FFFF, you will need to first relocate the EEPROM.  
Enabling the Security Feature on M68HC811E2 Devices with PCbug11 on the M68HC711E9PGMR, Rev. 0.1  
234  
Freescale Semiconductor  
To Execute the Program  
Step 6  
Erase the CONFIG to allow programming of NOSEC bit (bit 3). It is also recommended to program the  
EEPROM at this point before programming the CONFIG register. Refer to the engineering bulletin  
Programming MC68HC811E2 Devices with PCbug11 and the M68HC711E9PGMR, Freescale document  
number EB184.  
At the PCbug11command prompt, type: EEPROM ERASE BULK 103F  
Step 7  
You are now ready to enable the security feature on the MCHC811E2.  
At the PCbug11 command prompt, type: MS 103F 05  
The value $05 assumes the EEPROM is to be mapped from $0800 to $0FFF.  
Step 8  
After the programming operation is complete, verifying the CONFIG on the MCHC811E2 is not possible  
because in bootstrap mode the default value is always forced.  
Step 9  
The part is now in secure mode and whatever code you loaded into EEPROM will be erased if you tried  
to bring the microcontroller up in either expanded mode or bootstrap mode. The microcontroller will work  
properly in the secure mode only in single chip mode.  
NOTE  
If the part is placed in bootstrap mode or expanded mode, the code in  
EEPROM and RAM will be erased the microcontroller can be reused.  
Enabling the Security Feature on M68HC811E2 Devices with PCbug11 on the M68HC711E9PGMR, Rev. 0.1  
Freescale Semiconductor  
235  
To Execute the Program  
Enabling the Security Feature on M68HC811E2 Devices with PCbug11 on the M68HC711E9PGMR, Rev. 0.1  
Freescale Semiconductor  
236  
EB296  
Rev. 0.1, 07/2005  
Freescale Semiconductor  
Engineering Bulletin  
Programming MC68HC711E9  
Devices with PCbug11  
and the M68HC11EVBU  
By John Bodnar  
Austin, Texas  
Introduction  
The PCbug1software, needed along with the M68HC11EVBU to program MC68HC711E9 devices, is  
available from the download section of the Microcontroller Worldwide Web site  
http://www.freescale.com  
Retrieve the file pcbug342.exe (a self-extracting archive) from the MCU11 directory.  
Some Freescale evaluation board products also are shipped with PCbug11.  
NOTE  
For specific information about any of the PCbug11 commands, see the  
appropriate sections in the PCbug11 User's Manual (part number  
M68PCBUG11/D2), which is available from the Freescale Literature  
Distribution Center, as well as the Worldwide Web at  
http://www.freescale.com. The file is also on the software download system  
and is called pcbug11.pdf.  
© Freescale Semiconductor, Inc., 2005. All rights reserved.  
Programming Procedure  
Programming Procedure  
Once you have obtained PCbug11, use this step-by-step procedure to program your MC68HC711E9 part.  
Step 1  
Before applying power to the EVBU, remove the jumper from J7 and place it across J3 to ground  
the MODB pin.  
Place a jumper across J4 to ground the MODA pin. This will force the EVBU into special bootstrap  
mode on power up.  
Remove the resident MC68HC11E9 MCU from the EVBU.  
Place your MC68HC711E9 in the open socket with the notched corner of the part aligned with the  
notch on the PLCC socket.  
Connect the EVBU to one of your PC COM ports. Apply +5 volts to VDD and ground to GND on the  
power connector of your EVBU.  
Also take note of P4 connector pin 18. In step 5, you will connect a +12-volt (at most +12.5 volts)  
programming voltage through a 100-current limiting resistor to the XIRQ pin. Do not connect this  
programming voltage until you are instructed to do so in step 5.  
Step 2  
From a DOS command line prompt, start PCbug11 with  
C:\PCBUG11\> PCBUG11 –E PORT = 1 with the EVBU connected to COM1  
C:\PCBUG11\> PCBUG11 –E PORT = 2 with the EVBU connected to COM2  
PCbug11 only supports COM ports 1 and 2. If you have made the proper connections and have a high  
quality cable, you should quickly get a PCbug11 command prompt. If you do receive a Comms fault error,  
check your cable and board connections. Most PCbug11 communications problems can be traced to  
poorly made cables or bad board connections.  
Step 3  
PCbug11 defaults to base 10 for its input parameters; change this to hexadecimal by typing  
CONTROL BASE HEX  
Step 4  
You must declare the addresses of the EPROM array to PCbug11. To do this, type:  
EPROM D000 FFFF  
Step 5  
You are now ready to download your program into the EPROM.  
Connect +12 volts (at most +12.5 volts) through a 100-current limiting resistor to P4 connector  
pin 18, the XIRQ* pin.  
At the PCbug11 command prompt type: LOADS C:\MYPROG\ISHERE.S19  
Substitute the name of your program into the command above. Use a full path name if your program is  
not located in the same directory as PCbug11.  
Programming MC68HC711E9 Devices with PCbug11 and the M68HC11EVBU, Rev. 0.1  
238  
Freescale Semiconductor  
Programming Procedure  
Step 6  
After the programming operation is complete, PCbug11 will display this message  
Total bytes loaded: $xxxx  
Total bytes programmed: $yyyy  
You should now remove the programming voltage from P4 connector pin 18, the XIRQ* pin.  
Each ORG directive in your assembly language source will cause a pair of these lines to be  
generated. For this operation, $yyyy will be incremented by the size of each block of code  
programmed into the EPROM of the MC68HC711E9.  
PCbug11 will display the above message whether or not the programming operation was  
successful. As a precaution, you should have PCbug11 verify your code.  
At the PCbug11 command prompt type: VERF C:\MYPROG\ISHERE.S19  
Substitute the name of your program into the command above. Use a full path name if your program is  
not located in the same directory as PCbug11.  
If the verify operation fails, a list of addresses which did not program correctly is displayed. Should this  
occur, you probably need to erase your part more completely. To do so, allow the MC68HC711E9 to sit  
for at least 45 minutes under an ultraviolet light source. Attempt the programming operation again. If you  
have purchased devices in plastic packages (one-time programmable parts), you will need to try again  
with a new, unprogrammed device.  
Programming MC68HC711E9 Devices with PCbug11 and the M68HC11EVBU, Rev. 0.1  
Freescale Semiconductor  
239  
Programming Procedure  
Programming MC68HC711E9 Devices with PCbug11 and the M68HC11EVBU, Rev. 0.1  
Freescale Semiconductor  
240  
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LDCForFreescaleSemiconductor@hibbertgroup.com  
M68HC11E  
Rev. 5.1, 07/2005  

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