MAX66020K_技术文档

19-5540; Rev 0; 12/10

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

General Description

Features

The MAX66020 combines 1024 bits of user EEPROM, a

64-bit unique identifier (UID), and a 13.56MHz RF inter-

face (ISO/IEC 14443 Type B, Parts 2-4) in a plastic key

fob. The memory is organized as 16 blocks of 8 bytes

plus two more blocks for data and control registers.

Four adjacent user EEPROM blocks form a memory

page (pages 0 to 3). Memory protection features are

write protection and EPROM emulation, which the user

can set for each individual memory page. Memory

access is accomplished through the block transmission

protocol (ISO/IEC 14443-4), where requests and

responses are exchanged through I-blocks once a

device is in the ACTIVE state. The data rate can be as

high as 847.5kbps. The reader must support a frame

size of 19 bytes. The device supports an application

family identifier (AFI) and a card identifier (CID).

ISO/IEC 14443 functions not supported are chaining,

frame-waiting time extension, and power indication.

♦ Fully Compliant ISO/IEC 14443 (Parts 2-4) Type B

Interface

♦ 13.56MHz ±±7Hz Carrier Freꢀuency

♦ 1024-Bit User EEPROM with Bloc7 Loc7 Feature,

Write-Cycle Counter, and Optional EPROM-

Emulation Mode

♦ 64-Bit UID

♦ Read and Write (64-Bit Bloc7)

♦ Supports AFI and CID Function

♦ 10ms Maximum Programming Time

♦ To Fob: 10% ASK Modulation at 105.97bps,

211.97bps, 423.±57bps, or 84±.57bps

♦ From Fob: Load Modulation Using BPSK

Modulated Subcarrier at 105.97bps, 211.97bps,

423.±57bps, or 84±.57bps

♦ 200,000 Write/Erase Cycles (Minimum)

♦ 40-Year Data Retention (Minimum)

♦ Powered Entirely Through the RF Field

♦ Operating Temperature: -25°C to +50°C

Applications

Driver Identification (Fleet Application)

Access Control

Asset Tracking

Ordering Information

PART

TEMP RANGE

PIN-PACKAGE

Key Fob Mechanical Drawing appears at end of data sheet.

MAX66020K-000AA+

-25°C to +50°C

Key Fob

+Denotes a lead(Pb)-free/RoHS-compliant package.

Typical Operating Circuit

13.56MHz READER

MAGNETIC

COUPLING

MAX66020

IC LOAD

TX_OUT

TRANSMITTER

SWITCHED

LOAD

RX_IN

ANTENNA

________________________________________________________________ Maxim Integrated Products

1

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

ABSOLUTE MAXIMUM RATINGS

Maximum Incident Magnetic Field Strength ..........141.5dBµA/m

Operating Temperature Range ...........................-25°C to +50°C

Relative Humidity..............................................(Water Resistant)

Storage Temperature Range...............................-25°C to +50°C

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to

absolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

(T = -25°C to +50°C.) (Note 1)

A

MAX620

PARAMETER

EEPROM

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Programming Time

Endurance

t

9

10

ms

PROG

N

At +25°C

(Note 1)

200,000

40

Cycles

Years

CYCLE

Data Retention

t

RET

RF INTERFACE

Carrier Frequency

Operating Magnetic Field Strength

Power-Up Time

f

C

13.553 13.560 13.567

123.5

MHz

H

At +25°C (Note 1)

(Note 2)

137.5 dBμA/m

1.0 ms

t

POR

Note 1: System requirement.

Note 2: Measured from the time at which the incident field is present with strength greater than or equal to H

to the time at

(MIN)

which the MAX66020’s internal power-on reset signal is deasserted and the device is ready to receive a command frame.

Not characterized or production tested; guaranteed by simulation only.

2

_______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

blocks of user and control registers. Figure 2 shows the

Detailed Description

hierarchical structure of the ISO/IEC 14443 Type B-

compliant access protocol. The master must first apply

network function commands to put the MAX66020 into

the ACTIVE state before the memory and control func-

tions become accessible. The protocol required for

these network function commands is described in the

Network Function Commands section. Once the

MAX66020 is in the ACTIVE state, the master can issue

any one of the available memory and control function

commands. Upon completion of such a command, the

MAX66020 returns to the ACTIVE state and the master

can issue another memory and control function com-

mand or deselect the device, which returns it to the

HALT state. The protocol for these memory and control

function commands is described in the Memory and

Control Function Commands section. All data is read

and written least significant bit (LSb) first, starting with

the least significant byte (LSB).

The MAX66020 combines 1024 bits of user EEPROM,

128 bits of user and control registers, a 64-bit UID, and

a 13.56MHz RF interface (ISO/IEC 14443 Type B, Parts

2-4) in a single key fob. The memory is organized as 18

blocks of 8 bytes each. Four adjacent user EEPROM

blocks form a memory page (pages 0 to 3). Memory

protection features include write protection and EPROM

emulation, which the user can set for each individual

memory page. The memory of the MAX66020 is

accessed through the ISO/IEC 14443-4 block transmis-

sion protocol, where requests and responses are

exchanged through I-blocks once a device is in the

ACTIVE state. The reader must support a frame size of

at least 19 bytes. The data rate can be as high as

847.5kbps. The MAX66020 supports AFI and CID.

Functions not supported are chaining, frame-waiting

time extension, and power indication. Applications of

the MAX66020 include driver identification (fleet appli-

cation), access control, and asset tracking.

Parasite Power

As a wireless device, the MAX66020 is not connected

to any power source. It gets the energy for operation

from the surrounding RF field, which needs to have a

minimum strength as specified in the Electrical

Characteristics table.

Overview

Figure 1 shows the relationships between the major

control and memory sections of the MAX66020. The

device has three main data components: 64-bit UID,

four 256-bit pages of user EEPROM, and two 8-byte

INTERNALSUPPLY

VOLTAGE

REGULATOR

MEMORY AND

FUNCTION

CONTROL

UID

RF

FRONT-

ISO 14443

END

FRAME

FORMATTING

AND

ERROR

DATA

f

c

DETECTION

REGISTER

BLOCK

USER

EEPROM

MODULATION

Figure 1. Block Diagram

_______________________________________________________________________________________

3

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX66020

COMMAND LEVEL:

AVAILABLE COMMANDS:

DATA FIELD AFFECTED:

REQUEST (REQB)

WAKEUP (WUPB)

SLOT-MARKER

AFI, ADMINISTRATIVE DATA

(ADMINISTRATIVE DATA)

PUPI

NETWORK

FUNCTION COMMANDS

HALT (HLTB)

SELECT (ATTRIB)

DESELECT (DESELECT)

PUPI, ADMINISTRATIVE DATA

(ADMINISTRATIVE DATA)

MAX620

GET SYSTEM INFORMATION

WRITE SINGLE BLOCK

LOCK BLOCK

64-BIT UID, AFI, CONSTANTS

DATA OF SELECTED MEMORY BLOCK, APPLICABLE PROTECTION CONTROL REGISTER

PROTECTION CONTROL REGISTER

READ SINGLE BLOCK

READ SINGLE BLOCK WITH

BLOCK SECURITY STATUS

CUSTOM READ BLOCK

WRITE AFI

SELECTED MEMORY BLOCK

SELECTED MEMORY BLOCK, APPLICABLE PROTECTION CONTROL REGISTER

MEMORY AND CONTROL

FUNCTION COMMANDS

SELECTED MEMORY BLOCK, INTEGRITY BYTES

AFI BYTE

LOCK AFI

GET UID

AFI-LOCK BYTE

64-BIT UID

Figure 2. Hierarchical Structure of ISO/IEC 14443 Type B Protocol

MSb

LSb

1

64

57 56

49 48

45 44

37 36

E0h

2Bh

0h

FEATURE CODE (02h)

36-BIT IC SERIAL NUMBER

Figure 3. 64-Bit UID

which is transmitted as part of the ATQB response.

This way the master receives the complete UID in the

first response from the slave. See the Network

Function Commands section for details.

Unique Identification Number (UID)

Each MAX66020 contains a factory-programmed and

locked identification number that is 64 bits long

(Figure 3). The lower 36 bits are the serial number of

the chip. The next 8 bits store the device feature

code, which is 02h. Bits 45 to 48 are 0h. The code in

bit locations 49 to 56 identifies the chip manufacturer,

according to ISO/IEC 7816-6/AM1. This code is 2Bh

for Maxim. The code in the upper 8 bits is E0h. The

UID is read accessible through the Get UID and Get

System Information commands. The lower 32 bits of

the UID are transmitted in the PUPI field of the ATQB

response to the REQB, WUPB, or SLOT-MARKER

command. By default, the upper 32 bits of the UID are

factory programmed into the application data field,

Detailed Memory Description

The memory of the MAX66020 is organized as 18

blocks of 8 bytes each. Figure 4 shows the memory

map. The first 16 blocks (block numbers 00h to 0Fh in

hexadecimal counting) are the user EEPROM, the area

for application-specific data. Four adjacent blocks are

referred to as a page. Blocks 00h to 03h are page 0,

blocks 04h to 07h are page 1, blocks 08h to 0Bh are

page 2, and blocks 0Ch to 0Fh are page 3.

4

_______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

DATA BYTE NUMBER

INTEGRITY BYTES

BLOCK

NUMBER

(SEQUENCE LEFT TO RIGHT AS WRITTEN TO OR READ FROM DEVICE)

0

1

2

3

4

5

6

7

LSB

MSB

00h

01h

02h

03h

04h

05h

06h

07h

08h

09h

0Ah

0Bh

0Ch

0Dh

0Eh

0Fh

10h

11h

Page 0 User EEPROM R/(W)

Page 1 User EEPROM R/(W)

Page 2 User EEPROM R/(W)

Page 3 User EEPROM R/(W)

Write-Cycle Counter

ISO/IEC 14443 Application Data Field

BP1 BP2 BP3 BP4

AFI

U1

U2

U3

ADF-Lock AFI-Lock U1-Lock

S-Lock

Figure 4. Memory Map

Block 10h provides storage for user-programmable

parameters that are defined by the ISO/IEC 14443 stan-

dard. These are application data field and AFI. The

remaining bytes (U1, U2, U3) are not defined by the

communication standard; the application software can

use them, e.g., for proprietary markings. Block 11h con-

tains control bytes that determine the operation of the

individual pages (EPROM-emulation mode, write protec-

tion of individual blocks), or to write protect the applica-

tion data field, the AFI, and U1. The S-Lock byte, if

programmed to a suitable code, only protects itself from

future changes. The self-protection feature can be used

to permanently mark the fob as being “special,” as

defined by the application. Table 1 illustrates the rela-

tionship between the controlling register in block 11h

and the memory area affected. Tables 2 and 3 specify

the code assignments to achieve the protection.

Besides the storage for 8 data bytes, each memory

block has 2 integrity bytes, which are not memory

mapped. The integrity bytes function as a MAX66020-

maintained, 16-bit write-cycle counter. Having

reached its maximum value of 65,535, the write-cycle

counter stops incrementing, but does not prevent

additional write cycles to the memory block. The

integrity bytes can be read through the Custom Read

Block command.

_______________________________________________________________________________________

5

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

Table 1. Memory Protection Matrix

AFFECTED MEMORY AREA

CONTROLLING

BLOCKS

APPLICATION

REGISTER*

AFI

U1

S-LOCK

00h TO 03h 04h TO 07h 08h TO 0Bh 0Ch TO 0Fh DATA FIELD

BP1

BP2

E, W

—

E, W

—

W

—

W

—

W

—

W

BP3

—

E, W

—

BP4

—

E, W

—

MAX620

ADF-Lock

AFI-Lock

U1-Lock

S-Lock

—

*If programmed to a locking (protecting) code, the controlling register irreversibly protects itself from further changes. See Tables 2

and 3 for additional details.

Legend (Table 1):

CODE

DESCRIPTION

ERPOM-Emulation Mode

Write Protection

E

W

Table 2. BP1 to BP4 Protection Code Assignments

CODE

DESCRIPTION

00000000b

(00h)

Unlocked (factory default)

EPROM-Emulation Mode (irreversible)

BP1: blocks 00h to 03h

BP2: blocks 04h to 07h

00001010b

(0Ah)

BP3: blocks 08h to 0Bh

BP4: blocks 0Ch to 0Fh

Write-Protect Block Mode. Once set to Ah, the upper nibble cannot be changed to any other

value (irreversible). The bits of the lower nibble can still be changed only from 0 (unlocked) to 1

(locked) to write protect blocks individually.

b0: block 00h (BP1), block 04h (BP2), block 08h (BP3), block 0Ch (BP4)

b1: block 01h (BP1), block 05h (BP2), block 09h (BP3), block 0Dh (BP4)

b2: block 02h (BP1), block 06h (BP2), block 0Ah (BP3), block 0Eh (BP4)

b3: block 03h (BP1), block 07h (BP2), block 0Bh (BP3), block 0Fh (BP4)

1010<b3><b2><b1><b0>b

(Axh)

Note: Do not program the upper nibble of BP4 to 9 or 5, because this blocks the read access to blocks 0Ch to 0Fh.

Table 3. Protection Code Assignments for ADF-Loc7, AFI-Loc7, U1-Loc7, S-Loc7

CODE

00000000b (00h)

10101010b (AAh)

All other codes

DESCRIPTION

Unlocked (factory default)

Locked (irreversible)

Unlocked

6

_______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

LSb

BIT 1

MSb

BIT 8

1

0

START

BIT 2

BIT 3

BIT 4

BIT 5

BIT 6

BIT 7

STOP

Figure 5. ISO/IEC 14443 Data Character Format

STOP/IDLE

1

0

START

BIT 1

BIT 2

BIT 3

BIT 4

BIT 5

BIT 6

BIT 7

BIT 8

BIT 9

Figure 6. ISO/IEC 14443 SOF/EOF Character Format

SOF

ONE OR MORE DATA CHARACTERS

CRC (LSB)

CRC (MSB)

EOF

TIME

Figure 7. ISO/IEC 14443 Frame Format

For transmission, the frame information is modulated on a

carrier frequency, which is 13.56MHz for ISO/IEC 14443 .

The subsequent paragraphs are a concise description

of the required modulation and coding. For full details

including SOF/EOF and subcarrier on/off timing, refer to

ISO/IEC 14443-3, Sections 7.1 and 7.2.

ISO/IEC 14443 Type B

Communication Concept

The communication between the master and the

MAX66020 (slave) is based on the exchange of data

packets. The master initiates every transaction; only

one side (master or slaves) transmits information at any

time. Data packets are composed of characters, which

always begin with a START bit and typically end with

one or more STOP bits (Figure 5). The least significant

data bit is transmitted first. Data characters have 8 bits.

Each data packet begins with a start-of-frame (SOF)

character and ends with an end-of-frame (EOF) charac-

ter. The EOF/SOF characters have 9 all-zero data bits

(Figure 6). The SOF has 2 STOP bits, after which data

characters are transmitted. A data packet with at least

3 bytes between SOF and EOF is called a frame

(Figure 7). The last two data characters of an

ISO/IEC 14443 Type B frame are an inverted 16-bit

CRC of the preceding data characters generated

according to the CRC-16-CCITT polynomial. This CRC

is transmitted with the LSB first. For more details on the

CRC-16-CCITT, refer to ISO/IEC 14443-3, Annex B.

With network function commands, the command code,

parameters, and response are embedded between

SOF and CRC. With memory function commands, com-

mand code, and parameters are placed into the infor-

mation field of I-blocks (see the Block Types section),

which in turn are embedded between SOF and EOF.

The path from master to slave uses amplitude modula-

tion with a modulation index between 8% and 14%

(Figure 8). In this direction, a START bit and logic 0 bit

correspond to a modulated carrier; STOP bit and

logic 1 bit correspond to the unmodulated carrier. EOF

ends with an unmodulated carrier instead of STOP bits.

The path from slave to master uses an 847.5kHz sub-

carrier, which is modulated using binary phase-shift key

(BPSK) modulation. Depending on the data rate, the

transmission of a single bit takes eight, four, two, or one

subcarrier cycles. The slave generates the subcarrier

only when needed; i.e., starting shortly before an SOF

and ending shortly after an EOF. The standard defines

the phase of the subcarrier before the SOF as 0° refer-

ence, which corresponds to logic 1. The phase of the

subcarrier changes by 180° whenever there is a binary

transition in the character to be transmitted (Figure 9).

The first phase transition represents a change from

logic 1 to logic 0, which coincides with the beginning of

the SOF. The BPSK modulated subcarrier is used to

modulate the load on the fob’s antenna (Figure 10).

_______________________________________________________________________________________

±

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

CARRIER AMPLITUDE

A - B

A + B

MODULATION INDEX

1

M =

1

= 0.08 TO 0.14

0

1

0

1

A

MAX620

B

t

Figure 8. Downlink: 8% to 14% Amplitude Modulation

DATA TO BE TRANSMITTED

1

0

1

847kHz SUBCARRIER

BPSK MODULATION

OR

TRANSMISSION OF A SINGLE BIT

POWER-UP DEFAULT = EIGHT CYCLES OF 847kHz (9.44μs)

CAN BE REDUCED TO FOUR, TWO, OR ONE SUBCARRIER CYCLES FOR COMMUNICATION IN THE ACTIVE STATE.

INDICATES 180° PHASE CHANGE (POLARITY REVERSAL)

Figure 9. Uplink: BPSK Modulation of the 847.5kHz Subcarrier

8

_______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

DATA*

1

0

1

TRANSMISSION OF A SINGLE BIT

SHOWN AS EIGHT CYCLES OF THE 847kHz SUBCARRIER

*DEPENDING ON THE INITIAL PHASE, THE DATA POLARITY MAY BE INVERSE.

Figure 10. Uplink: Load Modulation of the RF Field by the BPSK Modulated Subcarrier

Block Types

ISO/IEC 14443 Block

Transmission Protocol

The standard defines three types of blocks: I-block,

R-block, and S-block. Figures 12, 13, and 14 show the

applicable PCB bit assignments.

Before the master can send a data packet to access the

memory, the MAX66020 must be in the ACTIVE state.

The protocol to put the MAX66020 into the ACTIVE state

is explained in the Network Function Commands sec-

tion. While in the ACTIVE state, the communication

between the master and the MAX66020 follows the

block transmission protocol as specified in Section 7 of

ISO/IEC 14443-4. Such a block (Figure 11) consists of

three parts: the prologue field, the information field, and

the epilogue field. The prologue can contain up to 3

bytes, called the protocol control byte (PCB), card iden-

tifier (CID), and the node address (NAD). Epilogue is

another name for the 16-bit CRC that precedes the EOF.

The information field is the general location for data.

The I-block is the main tool to access the memory. For

I-blocks, bit 2 must be 1 and bit 6, bit 7, and bit 8 must

be 0. Bit 5, marked as CH, is used to indicate chaining,

a function that is not used or supported by the

MAX66020. Therefore, bit 5 must always be 0. Bit 4,

marked as CID, is used by the master to indicate

whether the prologue field contains a CID byte. The

MAX66020 processes blocks with and without CID as

defined in the standard. The master must include the

CID byte if bit 4 is 1. Bit 3, marked as NAD, is used to

indicate whether the prologue field contains an NAD

byte, a feature not supported by the MAX66020.

Therefore, bit 3 must always be 0. Bit 1, marked as #, is

PROLOGUE FIELD

INFORMATION FIELD

EPILOGUE FIELD

CRC

(LSB)

CRC

(MSB)

PCB

CID

NAD

(DATA)

1 BYTE

0 OR MORE BYTES

1 BYTE

Figure 11. ISO/IEC 14443-4 Type B Block Format

MSb

LSb

BIT 1

#

MSb

LSb

BIT 8

0

BIT 7

0

BIT 6

0

BIT 5

CH

BIT 4

CID

BIT 3

NAD

BIT 2

1

BIT 8

1

BIT 7

BIT 6

1

BIT 5

AN

BIT 4

CID

BIT 3

0

BIT 2

1

BIT 1

#

0

Figure 12. Bit Assignments for I-Block PCB

Figure 13. Bit Assignments for R-Block PCB

_______________________________________________________________________________________

9

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

the master that the response is going to take longer than

specified by the frame-waiting time (FWT) (see the

ATQB Response section). However, the MAX66020

does not use this feature and consequently, the only use

of the S-block is to transition the device from the ACTIVE

state to the HALT state using the DESELECT command

(see the Network Function Commands section).

MSb

BIT 8

1

LSb

BIT 1

0

BIT 7

1

BIT 6

BIT 5

BIT 4

CID

BIT 3

0

BIT 2

1

Figure 14. Bit Assignments for S-Block PCB

Card Identifier

Figure 15 shows the bit assignment within the card

identifier byte. The purpose of bits 4 to 1 is to select

one of multiple slave devices that the master has ele-

vated to the ACTIVE state. The CID is assigned to a

slave through Param 4 of the ATTRIB command (see

the Network Function Commands section). While in

ACTIVE state, a compliant slave only processes blocks

that contain a matching CID and blocks without CID if

the assigned CID is all zeros. If the master includes a

CID, then the slave’s response also includes a CID

byte. Blocks with a nonmatching CIDs are ignored.

MSb

LSb

MAX620

BIT 8

0

BIT 7

0

BIT 6

0

BIT 5

0

BIT 4

BIT 3

BIT 2

BIT 1

(POWER LEVEL)

(FIXED)

CARD IDENTIFIER VALUE

Figure 15. Bit Assignments for CID Byte in I-Blocks

SOF PCB CID INFORMATION FIELD CRC (LSB) CRC (MSB) EOF

According to the standard, the slave can use bits 8 and

7 to inform the master whether power-level indication is

supported, and, if yes, whether sufficient power is avail-

able for full functionality. Since the MAX66020 does not

support power-level indication, the power-level bits are

always 00b. When the master transmits a CID byte, the

power-level bits must be 00b.

Figure 16. Frame Format for Block Transmission Protocol

the block number field. The block number is used to

ensure that the response received relates to the

request sent. This function is important in the error han-

dling, which is illustrated in Annex B of ISO/IEC 14443-

4. The rules that govern the numbering and handling of

blocks are found in Sections 7.5.3 and 7.5.4 of

ISO/IEC 14443-4. The MAX66020 ignores I-blocks that

have bit 5 or bit 3 set to 1.

Information Field

Since the MAX66020 does not generate WTX requests,

the information field (Figure 11) is found only with

I-blocks. The length of the information field is calculated

by counting the number of bytes of the whole block

minus length of prologue and epilogue field. The

ISO/IEC 14443 standard does not define any rules for

the contents of the information field. The MAX66020

assumes that the first byte it receives in the information

field is a command code followed by 0 or more com-

mand-specific parameters. When responding to an

I-block, the first byte of the information field indicates

success (code 00h) followed by command-specific

data or failure (code 01h) followed by one error code.

For R-blocks, the states of bit 2, bit 3, bit 6, bit 7, and

bit 8 are fixed and must be transmitted as shown in

Figure 13. The function of bit 1 (block number) and bit 4

(CID indicator) is the same as for I-blocks. Bit 5,

marked as AN, is used to acknowledge (if transmitted

as 0) or not to acknowledge (if transmitted as 1) the

reception of the last frame for recovery from certain

error conditions. The MAX66020 fully supports the func-

tion of the R-block as defined in the standard. For

details and the applicable rules, refer to Sections 7.5.3

and 7.5.4 and Annex B of ISO/IEC 14443-4.

Memory and Control

Function Commands

The commands described in this section are transmit-

ted using the block transmission protocol. The data of a

block (from prologue to epilogue) is embedded

between SOF and EOF, as shown in Figure 16. The CID

field (shaded) is optional. If the request contains a CID,

the response also contains a CID.

For S-blocks, the states of bit 1, bit 2, bit 3, and bit 7

and bit 8 are fixed and must be transmitted as shown in

Figure 14. The function of bit 4 (CID indicator) is the

same as for I-blocks. Bit 5 and bit 6, when 00b, specify

whether the S-block represents a deselect command. If

bit 5 and bit 6 are 11b, the S-block represents a frame-

waiting time extension (WTX) request, a feature to tell

10 ______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

Table 4. Error Code Matrix

FAILING COMMANDS

ERROR

CODE

ERROR DESCRIPTION

Invalid block number

10h

11h

12h

ꢀ

Already locked

ꢀ

Write access failed because block is locked

ꢀ

The command descriptions in this section only show

the information field of the I-blocks used to transmit

requests and responses. Since the MAX66020 neither

supports chaining nor generates WTX requests, when it

receives an I-block, the MAX66020 responds with an

I-block. The block number in the I-block response is the

same as in the I-block request.

specific data, as specified in the detailed command

description.

If the MAX66020 does not recognize a command, it

does not generate a response.

Detailed Command Descriptions

Get System Information

This command allows the master to retrieve technical

information about the MAX66020. In the response, the

least significant UID byte is transmitted first. The

response is adapted from ISO 15693-3, Section 10. The

IC reference code indicates the die revision in hexa-

decimal format, such as A1h, A2h, B1h, etc. To receive

the system information, issue a request with the com-

mand code 2Bh in the request information field.

Error Indication

Depending on the complexity of a function, various

error conditions can occur. In case of an error, the

response to a request begins with a 01h byte followed

by one error code.

Table 4 shows a matrix of commands and potential

errors. If there was no error, the information field of

the response begins with 00h followed by command-

Response Information Field for the Get System Information Command (No Error)

INFO

FLAGS

NUMBER OF

BLOCKS

MEMORY BLOCK

SIZE

INDICATOR

UID

U1

AFI

IC REFERENCE

00h

0Fh

(8 Bytes)

(1 Byte)

12h

07h

(1 Byte)

______________________________________________________________________________________ 11

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

Request Information Field for the Write Single Block Command

COMMAND

BLOCK NUMBER

NEW BLOCK DATA

21h

(1 Byte)

(8 Bytes)

Request Information Field for the Lock Block Command

Command

Block Number

22h

(1 Byte)

MAX620

Request Information Field for the Read Single Block Command

COMMAND

BLOCK NUMBER

20h

(1 Byte)

Response Information Field for the Read Single Block Command (No Error)

INDICATOR

MEMORY DATA

00h

(8 Bytes)

other cases, the data sent by the master arrives in the

buffer unaltered.

Write Single Block

The normal way to write data to the device is through

Write Single Block. This command uses one command-

specific parameter, which is the memory block number.

Valid block numbers are 00h to 11h. Writing a block

Lock Block

This command permanently locks (write protects) the

selected block and reports the success of the operation

takes t

. If this command is processed without any

PROG

in the response. Locking a block takes t

. If this

PROG

error, the response information field consists of an indi-

cator byte with the code 00h. The response is transmit-

ted after the memory is updated.

command is processed without any error, the response

information field consists of an indicator byte with the

code 00h. The response is transmitted after the protec-

tion byte is updated. The block protection can alterna-

tively be achieved by directly writing to memory block

11. Before using the Lock Block command, the final

block data should be defined and written to the device.

Depending on the protection settings of the memory

location to be updated, the MAX66020 manipulates

data as it arrives in a buffer. Upon receiving a Write

Single Block command for a write-protected location,

e.g., a self-locking nibble or byte in memory block 11h,

the buffer is loaded with the data already in memory,

rather than the data transmitted in the request.

Similarly, if the target memory block is in EPROM mode,

the buffer is loaded with the bitwise logical AND of the

transmitted data and data already in memory. In all

Read Single Block

This command allows for retrieving the data of a single

memory block. This command uses one command-spe-

cific parameter, which is the memory block number.

Valid block numbers are 00h to 11h.

12 ______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

Request Information Field for the Read Single Block with Block Security Status Command

COMMAND

BLOCK NUMBER

B0h

(1 Byte)

Response Information Field for the Read Single Block with Block Security

Status Command (No Error)

SECURITY STATUS

(SEE CODES BELOW)

INDICATOR

MEMORY DATA

00h

(1 Byte)

(8 Bytes)

00h = The memory block is not protected.

01h = The memory block is write protected.

Request Information Field for the Custom Read Block Command

COMMAND

A4h

BLOCK NUMBER

(1 Byte)

Response Information Field for the Custom Read Block Command (No Error)

INDICATOR

MEMORY DATA

INTEGRITY BYTES

00h

(8 Bytes)

(2 Bytes)

Read Single Block with Block

Custom Read Block

This command allows for retrieving the data of a single

block, followed by the block’s integrity bytes. This com-

mand uses one command-specific parameter, which is

the memory block number. Valid block numbers are

00h to 11h.

Security Status

This command allows for retrieving the security status

of a memory block followed by the memory block’s

data. This command uses one command-specific para-

meter, which is the memory block number. Valid block

numbers are 00h to 11h.

______________________________________________________________________________________ 13

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

Request Information Field for the Write AFI Command

COMMAND

AFI VALUE

27h

(1 Byte)

Response Information Field for the Get UID Command (No Error)

INDICATOR

00h

UID

(8 Bytes)

MAX620

Write AFI

ISO/IEC 14443-3 Type B Initialization

and Anticollision Protocol

This command writes the AFI byte and reports the suc-

cess of the operation in the response. The AFI byte can

alternatively be defined by writing to the proper loca-

tion in memory block 10h using the Write Single Block

command. If this command is processed without any

error, the response information field consists of an indi-

cator byte with the code 00h.

Before an ISO/IEC 14443-compliant RF device gives

access to its memory, a communication path between

the master and the RF device must be established.

Initially, the master has no information whether there

are any RF devices in the field of its antenna. To find

out whether there are one or more RF devices compli-

ant to a known standard in the field, the master uses a

standard-specific initialization and anticollision proto-

col. The ISO/IEC 14443 Type B protocol defines six

states: POWER-OFF, IDLE, WAITING FOR SLOT-

MARKER, READY, HALT, and ACTIVE. Figure 17

shows these states and the conditions under which a

slave transitions between states. For most cases, let-

ters surrounded by small circles reference the condi-

tion under which a transition occurs. The conditions

are explained in the legend to Figure 17. Table 5

explains terms that are used in the anticollision proto-

col and in the network function command description.

Lock AFI

This command permanently locks (write protects) the

AFI byte and reports the success of the operation in the

response. Before using the Lock AFI command, the AFI

byte should be written to the device using the Write AFI

command. The AFI byte can alternatively be locked by

writing the AFI-Lock byte in memory block 11h to AAh,

using the Write Single Block command. To lock the AFI,

issue a request with the command code 28h in the

request information field. If this command is processed

without any error, the response information field con-

sists of an indicator byte with the code 00h.

Get UID

This command allows the master to retrieve the

device’s unique identification number, UID. In the

response, the least significant UID byte is transmitted

first. To read the UID, issue a request with the com-

mand code 30h in the request information field.

14 ______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

RESPONSE LEGEND:

POWER-OFF

1

2

3

4

ATQB RESPONSE

ATTRIB RESPONSE

HLTB RESPONSE

OUT OF FIELD

(FROM ANY STATE)

IN FIELD

ANY OTHER

COMMAND

OR CASE

DESELECT RESPONSE

IDLE

S

A

ANY OTHER

COMMAND

OR CASE

WAITING FOR

SLOT-MARKER*

A

B

S

MS

B

a

1

s

1

READY

1

ANY OTHER

COMMAND OR CASE

ATTRIB WITH

MATCHING PUPI

b

2

HLTB WITH

EXECUTIVE BLOCK

TRANSMISSION

PROTOCOL FUNCTION

MATCHING PUPI

4

3

DESELECT

HALT

ACTIVE

(SPECIAL CASE OF A BLOCK TRANSMISSION

PROTOCOL FUNCTION)

ANY OTHER COMMAND

*WHEN ENTERING “WAITING FOR SLOT-MARKER,” EACH TAG SELECTS A RANDOM NUMBER R IN THE RANGE OF 1 TO “NUMBER OF SLOTS.”

CONDITIONS LEGEND:

NAME

DESCRIPTION

RESULT

A (AFI MISMATCH)

REQB/WUPB WITH NONMATCHING AFI

RETURN TO IDLE

a

WUPB WITH NONMATCHING AFI

B (BYPASS SM)

REQB/WUPB WITH MATCHING AFI AND [(N = 1) OR [R = 1)]

WUPB WITH MATCHING AFI AND [(N = 1) OR [R = 1)]

REQB/WUPB WITH MATCHING AFI AND (N ꢀ 1) AND (R ꢀ 1)

WUPB WITH MATCHING AFI AND (N ꢀ 1) AND (R ꢀ 1)

SLOT-MARKER COMMAND WITH SLOT NUMBER = R

TRANSITION DIRECTLY TO READY

b

S (SLOT-MARKER)

WAIT FOR MATCHING SLOT NUMBER

s

MS (MATCHING SLOT)

TRANSITION TO READY WITH MATCHING SLOT-MARKER

Figure 17. ISO/IEC 14443 Type B State Transitions Diagram

______________________________________________________________________________________ 15

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

Table 5. ISO/IEC 14443 Type B Technical Terms

TERM

DESCRIPTION

ACTIVE

One of the slave’s six states. In this state, the memory and control function commands and deselect apply.

Application Data Coding. 2-Bit field of the 3rd protocol info byte of the ATQB response.

Application Family Identifier. 1-Byte field used in the REQB/WUPB request to preselect slaves.

Answer to Request, Type B. Response to REQB, WUPB, and SLOT-MARKER command.

Slave Selection Command, Type B. Used to transition a slave from READY to the ACTIVE state.

Binary Phase-Shift Keying Modulation

ADC

AFI

ATQB

ATTRIB

BPSK

MAX620

Card Identifier. 4-Bit temporary identification number assigned to a slave through the ATTRIB command, used

in conjunction with the block transmission protocol.

CID

EOF

DESELECT

fc

End of Frame

Slave Deselection Command. Transitions the slave from the ACTIVE state to the HALT state.

Carrier Frequency = 13.56MHz

FO

Frame Option. 2-Bit field of the 3rd protocol info byte of the ATQB response.

fs

Subcarrier Frequency = f /16 = 847.5kHz

c

FWI

Frame-Waiting Time Integer. 4-bit field of the 3rd protocol info byte of the ATQB response.

Frame-Waiting Time. Calculated from FWI.

FWT

HALT

HLTB

IDLE

INF

One of the slave’s six states. The master puts a slave in this state to park it.

Halt Command, Type B

One of the slave’s six states. In this state, the slave has power and is waiting for action.

Information Field for Higher Layer Protocol (per ISO/IEC 14443-4)

Maximum Buffer Length Index of Slave (per ISO/IEC 14443-4). 4-Bit field of the first protocol info byte of the

ATQB response.

MBLI

N

Number of Anticollision Slots (or response probability per slot)

NAD

Node Address (per ISO/IEC 14443-4)

POWER-OFF

One of the slave’s six states. In this state, the slave has no power and consequently cannot do anything.

Pseudo Unique Identifier. 4-Byte field of the ATQB response.

PUPI

R

4-Bit Random Number Chosen by a Slave When Processing the REQB or WUPB Command

One of the slave’s six states; official name is READY-DECLARED SUBSTATE. In this state, the slave has

identified itself and is waiting for transition to ACTIVE (memory and control functions) or HALT (parking).

READY

REQB

RF

Request Command, Type B. Used to probe the RF field for the presence of slave devices.

Radio Frequency

S

Slot Number. 4-Bit field sent to slave with SLOT-MARKER command.

SLOT-MARKER Command used in the time-slot approach to identify slaves in the RF field

SOF

Start of Frame

TR0

Guard Time per ISO/IEC 14443-2

TR1

Synchronization Time per ISO/IEC 14443-2

WAITING FOR

One of the slave’s six states; official name is READY-REQUESTED SUBSTATE. In this state, the slave is

SLOT-MARKER waiting to be called by its random number R to transition to READY.

WUPB Wake-Up Command, Type B. Similar to REQB, required to wake up slaves in the HALT state.

16 ______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

READY State (READY DECLARED SUBSTATE)

The READY state applies to a slave that has met the cri-

teria in the anticollision protocol to send an ATQB

response. A slave can transition to READY from IDLE or

HALT (conditions B and b) or from WAITING FOR

SLOT-MARKER (conditions B and MS). When transition-

ing to the READY state, the slave transmits an ATQB

response. To maintain this state, the slave must contin-

uously receive sufficient power from the master’s RF

field to prevent transitioning into the POWER-OFF state.

A slave in the READY state listens to the commands

that the master sends, but reacts only on the REQB,

WUPB, ATTRIB and HLTB commands. From READY, a

slave can transition to ACTIVE (ATTRIB command with

matching PUPI), HALT (HLTB command with matching

PUPI), or IDLE (condition A).

ISO/IEC 14443 Type B States and

Transitions

POWER-OFF State

This state applies if the slave is outside the master’s RF

field. A slave transitions to the POWER-OFF state when

leaving the power-delivering RF field. When entering

the RF field, the slave automatically transitions to the

IDLE state.

IDLE State

The purpose of the IDLE state is to have the slave pop-

ulation ready to participate in the anticollision protocol.

When transitioning to the IDLE state, the slave does not

generate any response. To maintain this state, the slave

must continuously receive sufficient power from the

master’s RF field to prevent transitioning into the

POWER-OFF state. While in the IDLE state, the slave lis-

tens to the commands that the master sends, but reacts

only on the REQB and WUPB commands, provided that

they include a matching AFI value. If the master sends

a command with a nonmatching AFI byte (conditions A

and a), a transition to IDLE is also possible from the

HALT state, the READY state, and the WAITING FOR

SLOT-MARKER state. From IDLE, a slave can transition

to the higher states READY (condition B) or WAITING

FOR SLOT-MARKER (condition S). For details, see the

REQB/WUPB command description in the Network

Function Commands section.

HALT State

The HALT state is used to silence slaves that have

been identified and shall no longer participate in the

anticollion protocol. This state is also used to park

slaves after communication in the ACTIVE state was

completed. A slave transitions to the HALT state either

from READY (HLTB command with matching PUPI) or

from ACTIVE (DESELECT command with matching

CID). When transitioning to the HALT state, the slave

transmits a response that confirms the transition. To

maintain this state, the slave must continuously receive

sufficient power from the master’s RF field to prevent

transitioning into the POWER-OFF state. The normal

way out of the HALT state is through the WUPB com-

mand. From HALT, a slave can transition to IDLE (con-

dition a), READY (condition b), or WAITING FOR

SLOT-MARKER (condition s).

WAITING FOR SLOT-MARKER State

(READY REQUESTED SUBSTATE)

The WAITING FOR SLOT-MARKER state is used in the

time-slot anticollision approach. A slave can transition

to WAITING FOR SLOT-MARKER from the IDLE, HALT,

or READY state upon receiving a REQB or WUPB com-

mand with a matching AFI (conditions S and s), provid-

ed that both the number of slots specified in the

REQB/WUPB command and the random number that

the slave has chosen are different from 1. To maintain

this state, the slave must continuously receive sufficient

power from the master’s RF field to prevent transitioning

into the POWER-OFF state. A slave in the WAITING

FOR SLOT-MARKER state listens to the commands that

the master sends, but reacts only on the REQB, WUPB,

and SLOT-MARKER commands. From WAITING FOR

SLOT-MARKER, a slave can transition to the higher

state READY under condition B (bypassing the Slot-

MARKER), or MS (matching slot, SLOT-MARKER com-

mand with a slot number that matches the random

number R). Condition A (AFI mismatch) returns the

slave to the IDLE state.

ACTIVE State

The ACTIVE state enables the slave to process com-

mands sent through the block transmission protocol.

When entering the ACTIVE state, the slave confirms the

transition with a response. The only way for a slave to

transition to the ACTIVE state is from the READY state

(ATTRIB command with a matching PUPI). In the

ATTRIB command, the master assigns a 4-bit CID that

is used to address one of multiple slaves that could all

be in the ACTIVE state. To maintain this state, the slave

must continuously receive sufficient power from the

master’s RF field to prevent transitioning into the

POWER-OFF state. The normal way out of the ACTIVE

state is through the DESELECT command, which transi-

tions the slave to the HALT state.

______________________________________________________________________________________ 1±

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

response to REQB/WUPB is named ATQB. See the

ATQB Response section for details.

Network Function Commands

To transition slaves devices between states, the

ISO/IEC 14443 Type B standard defines six network

function commands, called REQB, WUPB, SLOT-

MARKER, HLTB, ATTRIB, and DESELECT. The master

issues the commands in the form of request frames and

the slaves respond by transmitting response frames.

With network function commands, command code,

parameters and response are embedded between SOF

and CRC. This section describes the format of the

response and request frames and the coding of the

data fields inside the frames as detailed as necessary

to operate the MAX66020. Not all of the fields and

cases that the standard defines are relevant for the

MAX66020. For a full description of those fields refer to

the ISO/IEC 14443-3, Section 7.

The ISO/IEC 14443 standard defines rules for the

assignment of the AFI codes and the behavior of the

slaves when receiving a REQB/WUPB request. If the

request specifies an AFI of 00h, a slave must process

the command regardless of its actual AFI value. If the

least significant nibble of the AFI in the request is

0000b, the slave must process the command only if the

most significant nibble of the AFI sent by the master

matches the most significant nibble of the slave’s AFI.

For all other AFI values, the slave processes the com-

mand only if the AFI in the request and the slave match.

The AFI code can be programmed and locked by the

user. For details see the Memory and Control Function

Commands section.

MAX620

The bit assignments of the PARAM byte are shown in

Figure 19. Bits 5 to 8 are reserved and must be trans-

mitted as 0. Bit 4, if 0, indicates that the request is a

REQB command; bit 4, if 1, defines a WUPB command.

REQB/WUPB Command

The REQUEST command, Type B (REQB) and the

WAKEUP command, Type B (WUPB) are the general

tools for the master to probe the RF field for the presence

of slave devices and to preselect them for action based

on the value of the application family identifier (AFI). An

ISO/IEC 14443 Type B-compliant slave watches for these

commands while in the IDLE state, WAITING FOR SLOT-

MARKER state, and READY state. In the HALT state, the

slave only acts upon receiving a WUPB command. The

REQB or WUPB command is transmitted as a frame, as

shown in Figure 18. Besides the command code, the

request includes two parameters, AFI and PARAM. The

Bits 1, 2, and 3 specify the number of slots (N) to be

used in the anticollision protocol. Table 6 shows the

codes. In the case of N = 1, the SLOT-MARKER com-

mand does not apply and all slaves with a matching AFI

transition to the READY state. With multiple slaves in the

field, this leads to a data collision, since the response

frames are transmitted simultaneously. If N is larger than

1, each slave in the field selects its own 4-bit random

number, R, in the range of 1 to N. A slave that happens

MSb

BIT 8

0

LSb

BIT 7

0

BIT 6

0

BIT 5

0

BIT 4

BIT 3

BIT 2

N

BIT 1

SOF COMMAND

05h

AFI

PARAM

CRC

EOF

(1 BYTE)

(2 BYTES)

REQB/

WUPB

(FIXED)

Figure 18. REQB/WUPB Request Frame

Figure 19. Bit Assignments for PARAM Byte

Table 6. Number of Slots Codes

BIT 3

BIT 2

BIT 1

N

0

1

0

1

0

1

0

1

0

1

0

1

2

4

8

16

1

X

(RESERVED)

18 ______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

to choose R = 1 responds to the REQB/WUPB request.

The bits marked as “nnnn” specify the slot number as

defined in the Table 7. Any sequence of the allowable

slot numbers is permitted.

The larger N is the lower the probability of colliding

response frames; however, if N is 16 and there is only a

single slave in the field, it can take up to 15 SLOT-

MARKER commands to get a response. The method to

identify all slaves in the field relying solely on the ran-

dom number R and the REQB/WUPB command is

called the “probabilistic approach.” For mode informa-

tion about the anticollision process, see the Anticollision

Examples section.

ATQB Response

The response for both the REQB/WUPB and the SLOT-

MARKER command is called ATQB, which stands for

“answer to request, Type B.” Figure 21 shows the for-

mat of the ATQB response. The PUPI field (pseudo-

unique identifier) is used by the master to address a

slave for transitioning to the ACTIVE or HALT state. The

data reported as PUPI is the least significant 4 bytes of

the 64-bit UID. The application data field reports user-

defined data that is relevant for distinguishing otherwise

equal slaves in the RF field. Application data is the first

4 bytes of memory block 10h. By default, the applica-

tion data field is factory programmed to reflect the most

significant 4 bytes of the 64-bit UID. This allows the

master to obtain the full 64-bit UID in the first response

from the slave. However, since this field is not factory

locked, it may be written to any value.

SLOT-MARKER Command

Instead of relying on the fact that a participating slave

chooses a new random number for every REQB/WUPB

command, in the “time-slot approach” the master calls

the slaves by their random number R using the SLOT-

MARKER command. Before this can be done, the mas-

ter must have issued the REQB/WUPB command with a

number of slots (N) value greater than 1. The master

can send up to (N - 1) SLOT-MARKER commands.

Figure 20 shows the format of the SLOT-MARKER

request frame. The AFI field is not needed since the

slaves have already been preselected through the pre-

ceding REQB/WUPB request. The response to the

SLOT-MARKER command is called ATQB. See the

ATQB Response section for details.

The protocol info field provides the master with admin-

istrative information, such as data rate, frame size,

ISO/IEC 14443-4 compliance, frame waiting time, and

whether the slave supports CID and NAD in the

ISO/IEC 14443-4 block transmission protocol. Figure 22

SOF COMMAND

CRC

EOF

SOF INDICATOR

50h

PUPI

APPLICATION DATA PROTOCOL INFO

(4 BYTES) (3 BYTES)

CRC

EOF

(4 BYTES)

(2 BYTES)

nnnn0101b (2 BYTES)

Figure 20. SLOT-MARKER Request Frame

Figure 21. ATQB Response Frame

Table ±. Slot Numbering

BIT 8

BIT 7

BIT 6

BIT 5

SLOT NUMBER

0

1

0

2

3

0

1

4

…

1

…

1

…

1

…

0

…

15

16

1

______________________________________________________________________________________ 19

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

3RD BYTE,

UPPER NIBBLE

3RD BYTE,

BIT 4, BIT 3

3RD BYTE,

BIT 2, BIT 1

1ST BYTE

2ND BYTE

BIT RATE CABILITY MAXIMUM FRAME SIZE, PROTOCOL TYPE

FWI

ADC

00b

FO

77h

11h

0110b

01b

Figure 22. Protocol Info Field Details

SOF COMMAND

50h

PUPI

CRC

EOF

SOF INDICATOR

00h

CRC

EOF

MAX620

(4 BYTES) (2 BYTES)

(2 BYTES)

Figure 23. HLTB Request Frame

Figure 24. HLTB Response Frame

shows where this information is located in the protocol

info field and what the values are.

the HALT state, the slave only responds to the WUPB

request.

The bit-rate capability of the MAX66020 ranges from

105.9kbps to 847.5kbps in both directions (request and

response); request and response bit rate need not be

the same. The maximum frame size (upper nibble of the

2nd byte) of any request/response specifies 24 bytes.

The largest frame that occurs with the MAX66020 is 19

bytes (Get System Information response). The protocol

type (lower nibble of the 2nd byte) specifies that the

MAX66020 supports the ISO/IEC 14443-4 block trans-

mission protocol. The FWI code 0110b specifies a

frame waiting time of 19.3ms. Note that a slave may

respond long before the maximum frame waiting time is

expired. The ADC code 00b specifies that the

MAX66020 uses proprietary coding for the application

data field. The FO code 01b implies that the MAX66020

supports CID, but does not support the NAD field in the

ISO/IEC 14443-4 block transmission protocol.

ATTRIB Command

The ATTRIB command is the only way to select a slave

and make it process commands that are transmitted

according to the ISO/IEC 14443 block transmission pro-

tocol. If, based on the ATQB response, the master

wants to communicate with the slave, the master must

put the slave into the ACTIVE state using the slave

selection command ATTRIB. The normal way for the

master to move a slave out of the ACTIVE state is by

sending a DESELECT command, which uses an

S-block to convey a network function command.

Figure 25 shows the format of the ATTRIB request

frame. The data to be used in the PUPI field must

match the PUPI information that the slave has transmit-

ted in the ATQB response. Param 1 tells the slave how

much time the master needs to switch from transmit to

receive (TR0), how much time the master needs to syn-

chronize to the slave’s subcarrier (TR1), and whether

the master is capable of receiving response frames

without SOF and/or EOF.

HLTB Command

The HLTB command is the only network function com-

mand to silence a slave by parking it in the HALT state.

If, based on the ATQB response, the master does not

want to further communicate with the slave, the master

issues the HLTB command. Figures 23 and 24 show

the format of the HLTB request frame and the corre-

sponding response frame. The data to be used in the

PUPI field must match the PUPI information that the

slave has transmitted in the ATQB response. While in

The MAX66020 ignores the data of Param 1. To ease

requirements for ISO/IEC 14443 Type B readers, the

MAX66020 has TR0 and TR1 fixed at 128/fs (151µs; fs

is the subcarrier frequency of 847.5kHz) and always

begins and ends its responses with SOF and EOF,

respectively.

SOF COMMAND

1Dh

PUPI

PARAM 1

(1 BYTE)

PARAM 2

(1 BYTE)

PARAM 3

01h

PARAM 4

HLINF

CRC

EOF

(4 BYTES)

(1 BYTE) (≥ 0 BYTES) (2 BYTES)

Figure 25. ATTRIB Request Frame

20 ______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

sets the upper nibble of Param 3 to 0000b, the Param 3

value to be used for the MAX66020 in the ATTRIB

MSB

BIT 8

LSB

request is 01h.

BIT 7

BIT 6

BIT 5

BIT 4

X

BIT 3

X

BIT 2

X

BIT 1

X

Param 4 assigns the slave the CID number that is used

with the block transmission protocol to address one of

several slaves in the ACTIVE state. Figure 27 shows the

Param 4 bit assignments. Since the MAX66020 sup-

ports the CID field, the master can assign any number

in the range from 0 to 14. According to ISO/IEC 14443-

3, code 15 is reserved.

RESPONSE DATA RESPONSE DATA

RATE (UPLINK) RATE (DOWNLINK)

RECEIVER FRAME SIZE CAPABILITY

Figure 26. Bit Assignments for Param 2 Byte

MSB

LSB

The ATTRIB request frame contains one optional field,

called higher layer information (HLINF). This field can

be used to include data as in the information field of the

ISO/IEC 14443 Type B block transmission protocol (see

Figure 11). If such data is present and the slave sup-

ports the HLINF field, then the slave processes the

HLINF data and returns the result in its response to the

ATTRIB request. Typically, the ATTRIB request is trans-

mitted without HLINF field. The only HLINF data that the

MAX66020 accepts and processes is the Get UID com-

mand, code 30h.

BIT 8

0

BIT 7

0

BIT 6

0

BIT 5

0

BIT 4

BIT 3

BIT 2

BIT 1

(FIXED)

CARD IDENTIFIER VALUE (CID)

Figure 27. Bit Assignments for Param 4 Byte

SOF INDICATOR HL RESPONSE

MBLI, CID (≥ 0 BYTES)

CRC

(2 BYTES)

EOF

If the ATTRIB request has a matching PUPI and a valid

CRC, the slave transmits an ATTRIB response frame, as

shown in Figure 28. The upper nibble of the indicator,

also referred to as MBLI, is 0000b, telling that the slave

does not provide any information on its internal input

buffer size; the lower nibble returns the card identifier

value that the master has just assigned to the slave.

Figure 28. ATTRIB Response Frame

FRAME WITHOUT CID

SOF COMMAND

C2h

CRC

EOF

(2 BYTES)

The HL response field is optional. There are three

cases to be distinguished:

FRAME WITH CID

SOF COMMAND

CAh

a) If there was no HLINF field in the ATTRIB request,

then there is no HL response field in the response.

CID

CRC

EOF

(1 BYTE)

(2 BYTES)

b) If there was a Get UID command code (30h) in the

HLINF field of the ATTRIB request, then the HL

response field is identical to the Get UID response

information field (i.e., 00h followed by the 8-byte UID).

Figure 29. DESELECT Request and Response Frames

Param 2 informs the slave about the data rate that shall

be used for communication in the ACTIVE state and the

maximum frame size that the master can receive.

Figure 26 shows the bit assignments for the Param 2

byte. The MAX66020 supports the data rates of

105.9kbps (code 00b), 211.9kbps (code 01b),

423.75kbps (code 10b), and 847.5kbps (code 11b).

The master can choose different data rates for request

and response. Since it does not support chaining, the

MAX66020 ignores the frame size capability and

assumes that the master can receive frames as large

as specified in the ATQB response.

c) If the code in the HLINF field of the ATTRIB request

was different from 30h, then the response frame does

not contain an HL response field.

DESELECT Command

The DESELECT command is used to transition the slave

from the ACTIVE to the HALT state after the master has

completed the communication with the slave. There are

two versions of the deselect request frame, one without

CID and one with CID. Figure 29 shows both versions.

Figure 27 shows the CID format.

Logically, the DESELECT command is a special case of

the S-block of the block transmission protocol, as

defined in part 4 of the ISO/IEC 14443 standard. The

MAX66020 responds to a DESELECT command if the

The lower nibble of Param 3 is used to confirm the pro-

tocol type as specified in the lower nibble of the second

byte of the ATQB protocol info. Since ISO/IEC 14443-3

______________________________________________________________________________________ 21

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

CID in the request and the CID in the device match. If

the DESELECT request does not include a CID, the

MAX66020 only responds to the request if its CID is

0000b.

An ATQB response received with a CRC error indicates

a collision because two or more slaves have responded

at the same time. With probabilistic anticollision, the

master must issue another REQB command to cause

the slaves in the field that are not in the HALT or

ACTIVE state to select a new random number R. If one

of the slaves has chosen R = 1, it responds with ATQB.

A REQB without ATQB response does not guaran-

tee that all slaves in the field have been identified.

The response frame to the DESELECT command is

identical to the request frame. The slave returns the

same data that it had received, confirming that the

slave addressed in the request has been transitioned to

the HALT sate.

Figure 30 shows an example of the time-slot anticolli-

sion, assuming that there are four slaves in IDLE state in

the field. The process begins with the master sending

an REQB request with N = 1, which forces all slaves to

respond with ATQB, resulting in a collision. Knowing that

slaves are present, the master now sends REQB with N

= 8. This causes all slaves to select a random number in

the range of 1 to 8. Only the slave that has chosen R = 1

responds, which is slave C in the example. Knowing that

there are more slaves in the field, the master continues

issuing REQB commands, which in the example, even-

tually identifies all slaves. Due to its statistical nature,

probabilistic anticollision is less likely to find every slave

in the field than the time-slot anticollision.

MAX620

Anticollision Examples

Probabilistic Anticollision

The master starts the anticollision process by issuing an

REQB or WUPB command. The WUPB command

involves any slave in the field with a matching AFI code.

The REQB command performs the same function, but is

ignored by slaves in the HALT state. Both commands

include the parameter N, which according to Table 6 is

used to set the probability of an ATQB response to 1/N.

If N = 1, all participating slaves respond with the ATQB

response. If N is greater than one, then each slave

selects a random number R in the range of 1 to N. If a

slave happens to choose R = 1, then it responds with

ATQB. If R is greater than 1, then the slave waits for

another REQB or WUPB command, which causes the

participating slaves to choose a new random number R.

Time-Slot Anticollision

The master starts the anticollision process by issuing

an REQB or WUPB command. The WUPB command

involves any slave in the field with a matching AFI code.

The REQB command performs the same function, but is

ignored by slaves in the HALT state. Both commands

include the parameter N, which according to Table 6

specifies the number of slots to be used in the anticolli-

sion protocol.

The ATQB response contains a field named PUPI,

which is used to direct commands to a specific slave

during the anticollision process. When the master

receives an ATQB response, it should issue a matching

HLTB command to halt the slave or issue a matching

ATTRIB command to assign a CID and place the slave

in the ACTIVE state. If this is not done, the slaves con-

tinue to participate in the anticollision process. A slave

in the ACTIVE state ignores all REQB, WUPB, SLOT-

MARKER, ATTRIB, and HLTB commands, but responds

to the DESELECT command.

If N = 1, all participating slaves respond with the ATQB

response. If N is greater than one, then each slave

selects a random number R in the range of 1 to N. If a

slave happens to choose R = 1, then it responds with

ATQB. If R is greater than 1, then the slave waits for a

TESTING FOR SLAVES

ATTEMPT 1

ATTEMPT 2

ATTEMPT 3

ATTEMPT 4 ATTEMPT 5

ATTEMPT 6

REQB

(N = 1)

REQB

(N = 8)

REQB

(N = 8)

REQB

(N = 8)

REQB

(N = 8)

REQB

(N = 8)

REQB

(N = 8)

MASTER

SLAVE A

SLAVE B

SLAVE C

SLAVE D

ATQB

(R = 3)

(R = 6)

(R = 7)

(R = 4)

(R = 1) ATQB (R = 3)

(R = 6)

(R = 5)

(R = 3)

(R = 4)

(R = 8)

(R = 2)

(R = 8)

(R = 4)

(R = 8)

(R = 1) ATQB

(R = 4)

(R = 1) ATQB (R = 8)

(R = 2)

(R = 1) ATQB (R = 5)

(R = 2)

Figure 30. Probabilistic Anticollision Example

22 ______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

TESTING FOR SLAVES

SLOT 1

REQB

SLOT 2

SM2

SLOT 3

SM3

SLOT 4 SLOT 5

SM4 SM5

SLOT 6

SM6

SLOT 7 SLOT 8

SM7 SM8

REQB

(N = 1)

MASTER

(N = 8)

SLAVE A

SLAVE B

SLAVE C

SLAVE D

ATQB

(R = 3)

ATQB

(R = 6)

ATQB

(R = 1) ATQB

(R = 2)

ATQB

Figure 31. Time-Slot Anticollision Example

SLOT-MARKER command with a slot number that is

equal to R and then responds with ATQB. The master

must try all slot numbers from 2 to N to ensure that no

slave is missed.

to respond with ATQB, resulting in a collision. Knowing

that slaves are present, the master now sends REQB

with N = 8. This causes all slaves to select a random

number in the range of 1 to 8. This does not prevent

two slaves from choosing the same value for R, but the

higher N is, the less likely this is to occur. In the exam-

ple, slave C has chosen R = 1 and responds right after

REQB. The master now sends a SLOT-MARKER com-

mand with slot number 2 (SM2), which causes slave D

to respond. The master continues testing all slots, and,

if a slave with matching R is present, receives an

ATQB. In case the master detects a collision in a slot,

the slaves identified in the remaining slots need to be

put in the HALT or ACTIVE state first, before another

anticollision process is started. Note that there is no

need for the master to test the slots in numerical order,

as in the example.

The ATQB response contains a field named PUPI,

which is used to direct commands to a specific slave

during the anticollision process. When the master

receives an ATQB response, it should issue a matching

HLTB command to halt the slave, or issue a matching

ATTRIB command to assign a CID and place the slave

in the ACTIVE state. A slave in the ACTIVE state ignores

all REQB, WUPB, SLOT-MARKER, ATTRIB, and HLTB

commands, but responds to the DESELECT command.

An ATQB response received with a CRC error indicates

a collision because two or more slaves have responded

at the same time. Typically the master continues issuing

SLOT-MARKER commands to test for slaves with ran-

dom numbers R different from 1. If additional collisions

were encountered, the master must issue a new REQB

command, causing each slave in the field that is not in

the HALT or ACTIVE state to select a new random num-

ber R. The anticollision process then continues in this

manner until all slaves in the field have been identified

and put either into the HALT or ACTIVE state.

CRC Generation

The ISO/IEC 14443 standard uses a 16-bit CRC, gener-

ated according to the CRC-16-CCITT polynomial func-

16

12

5

tion: X + X + X + 1 (Figure 32). This CRC is used

for error detection in request and response data pack-

ets and is always communicated in the inverted form.

After all data bytes are shifted into the CRC generator,

the state of the 16 flip-flops is parallel-copied to a shift

register and shifted out for transmission with the LSb

first. For more details on this CRC refer to ISO/IEC

14443-3, Annex B, CRC_B encoding.

Figure 31 shows an example of the time-slot anticolli-

sion, assuming that there are four slaves in IDLE state

in the field. The process begins with the master send-

ing an REQB request with N = 1, which forces all slaves

______________________________________________________________________________________ 23

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

16

12

5

POLYNOMIAL = X + X + X + 1

MSb

1ST

2ND

3RD

4TH

5TH

6TH

7TH

8TH

STAGE

0

1

2

3

4

5

6

7

X

MAX620

LSb

9TH

STAGE

10TH

STAGE

11TH

STAGE

12TH

STAGE

13TH

STAGE

14TH

STAGE

15TH

STAGE

16TH

STAGE

8

9

10

11

12

13

14

15

16

X

INPUT DATA

Figure 32. CRC-16-CCITT Generator

Key Fob Mechanical Drawing

TOP VIEW

54mm

28mm

7.7mm

MAX66020K-000AA+

1.6mm

SIDE VIEW

24 ______________________________________________________________________________________

ISO/IEC 14443 Type B-Compliant

1Kb Memory Fob

MAX620

Revision History

REVISION REVISION

PAGES

DESCRIPTION

CHANGED

NUMBER

DATE

0

12/10

Initial release

—

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 25

Maxim is a registered trademark of Maxim Integrated Products, Inc.


型号：	MAX66020K
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	ISO/IEC 14443 Type B-Compliant 1Kb Memory Fob Read and Write (64-Bit Block) ISO / IEC 14443 B型兼容的1K位存储器FOB读取和写入（ 64位块）存储
文件：	总25页 (文件大小：355K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

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