ICS9248-64 [ICSI]

AMD-K7TM System Clock Chip; AMD- K7TM系统时钟芯片
ICS9248-64
型号: ICS9248-64
厂家: INTEGRATED CIRCUIT SOLUTION INC    INTEGRATED CIRCUIT SOLUTION INC
描述:

AMD-K7TM System Clock Chip
AMD- K7TM系统时钟芯片

时钟
文件: 总15页 (文件大小:143K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
Integrated  
Circuit  
Systems, Inc.  
ICS9248-64  
TM  
AMD-K7 System Clock Chip  
General Description  
Features  
The ICS9248-64 is a main clock synthesizer chip for AMD-  
K7 based systems. This provides all clocks required for such  
a system when used with a Zero Delay Buffer Chip such as  
the ICS9179-06.  
Generates the following system clocks:  
- 3 differential pair open drain CPU clocks  
(1.5V external  
pull-up; up to 133MHz).  
- 8 PCI including 1 free running (3.3V) @33.3MHz.  
- 2AGP(3.3V) up to 66.6MHz.  
- 2 REF(3.3V)@14.318MHz  
- 1 48MHz(3.3V)  
Spread Spectrum may be enabled by driving the SPREAD#  
pin active. Spread spectrum typically reduces system EMI by  
8dB to 10dB. This simplifies EMI qualification without  
resorting to board design iterations or costly shielding. The  
ICS9248-64 employs a proprietary closed loop design, which  
tightly controls the percentage of spreading over process and  
temperature variations.  
- 24 / 48MHz(3.3V)  
Skew characteristics:  
- CPU -CPU<250ps  
- CPUt - CPUc <200ps (differential pair)  
- PCI – PCI: <500ps  
- CPU – SDRAM_OUT: < 250ps  
- CPU AGP <500ps  
Efficient Power Management through PD#, PCI_STOP#  
and CPU_STOP#.  
Spread Spectrum option for EMI reduction  
(-1.0% down spread).  
Block Diagram  
Uses external 14.318 MHz crystal  
Pin Configuration  
*FS0/REF0  
*FS1/REF1  
GNDREF  
X1  
1
2
3
4
5
6
7
8
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
48  
47  
46  
45  
44  
43  
42  
41  
40  
39  
38  
37  
36  
35  
34  
33  
32  
31  
30  
29  
28  
27  
26  
25  
VDDREF  
GNDSD  
SDRAM_OUT  
VDDSD  
X2  
RESERVED  
CPUCLKC2  
CPUCLKT2  
GNDCPU  
CUCLKC1  
CPUCLKT1  
GND  
CPUCLKC0  
CPUCLKT0  
RESERVED  
VDD  
GNDPCI  
PCICLK_F  
PCICLK0  
VDDPCI  
PCICLK1  
PCICLK2  
GNDPCI  
PCICLK3  
PCICLK4  
VDDPCI  
PCICLK5  
PCICLK6  
VDDAGP  
AGP0  
AGP1  
GNDAGP  
VDD48  
GND  
PCI_STOP#  
CPU_STOP#  
PD#  
SPREAD#  
TEST#  
SDATA  
SCLK  
GND48  
I2C  
{
48MHz  
SEL24_48#/24-48MHz  
48-Pin SSOP  
* Internal 120K pullup resistor on indicated inputs  
AMD-K is a trademark of Advanced Micro Devices.  
ICS reserves the right to make changes in the device data identified in  
this publication without further notice. ICS advises its customers to  
obtain the latest version of all device data to verify that any  
9248-64RevC03/19/01  
information being relied upon by the customer is current and accurate.  
ICS9248-64  
Pin Descriptions  
PIN NUMBER  
PIN NAME  
FS(0:1)  
REF(0:1)  
GNDREF  
TYPE  
IN  
OUT  
PWR  
DESCRIPTION  
Frequency Select pins, has pull-up to VDD  
14.318MHz clock output  
1, 2  
3
Ground for REF outputs  
XTAL_IN 14.318MHz Crystal input, has internal 33pF load  
cap and feed back resistor from X2  
XTAL_OUT Crystal output, has internal load cap 33pF  
Ground for PCI outputs  
4
X1  
IN  
5
X2  
GNDPCI  
OUT  
PWR  
6, 12  
Free Running PCI output. Not affected by the PCI_STOP#  
input.  
7
PCICLK_F  
OUT  
OUT  
8, 10, 11, 13,  
14,16,17  
9, 15  
PCICLK (0:6)  
PCI clock outputs. TTL compatible 3.3V  
VDDPCI  
VDDAGP  
AGP (0:1)  
GNDAGP  
VDD48  
PWR  
PWR  
OUT  
PWR  
PWR  
OUT  
Power for PCICLK outputs, nominally 3.3V  
Power for AGP outputs, nominally 3.3V  
AGP outputs defined as 2X PCI. These may not be stopped.  
Ground for AGP clock outputs  
Power for USB, FDC outputs nominally 3.3V  
48MHz output  
18  
19, 20  
21  
22  
23  
48MHz  
Selects 24 or 48MHz output for pin 24  
Low = 48MHz High = 24MHz  
SEL24-48#  
IN  
24  
24-48MHz  
GND48  
SCLK  
OUT  
PWR  
IN  
Fixed clock out selectable through SEL24-48#  
Ground for 48MHz outputs  
25  
26  
27  
Clock input for I2C  
SDATA  
IN  
Data input for I2C  
Tri State or test mode when low  
(please refer to frequency table)  
Enables Spread Spectrum feature when LOW. Down Spread  
0.5% modulation frequency =50KHz  
Powers down chip, active low. Internal PLL & all outputs are  
disabled.  
28  
29  
30  
TEST#  
SPREAD#  
PD#  
IN  
IN  
IN  
Halts CPUCLKs. CPUCLKT(0:2) is driven LOW whereas  
CPUCLKC(0:2) is driven HIGH when this pin is asserted  
(Active LOW).  
31  
CPU_STOP#  
IN  
Halts PCI Bus at logic "0" level when driven low. PCICLK_F  
is not affected by this pin  
32  
PCI_STOP#  
IN  
33  
34  
35, 44  
GND  
VDD  
RESERVED  
PWR  
PWR  
N/C  
Isolated ground for core  
Isolated power for core, nominally 3.3V  
Furture CPU power rail  
"True" clocks of differential pair CPU outputs. These open  
drain outputs need an external 1.5V pull-up.  
"Complementory" clocks of differental pair CPU output. These  
open drain outputs need an external 1.5V pull_up.  
Ground for CPUCLK outputs.  
36, 39, 42,  
37, 40, 43  
CPUCLKT (0:2)  
CPUCLKC(0:2)  
OUT  
OUT  
38, 41  
45  
GNDCPU  
VDDSD  
PWR  
PWR  
OUT  
PWR  
PWR  
Power for SDRAM_OUT pin. Norminally 3.3V  
Reference clock for SDRAM zero delay buffer  
Ground for SDRAM_OUT pins  
46  
47  
48  
SDRAM_OUT  
GNDSD  
VDDREF  
Power for REF (0:1), X1, X2, nominally 3.3V  
2
ICS9248-64  
Frequency Select  
CPU,  
SDRAM  
TEST# FS1 FS0  
PCI  
AGP  
48MHz  
REF  
Comments  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Hi-Z  
50.0  
66.6  
Hi-Z  
25.0  
33.3  
Hi-Z  
50.0  
66.6  
Hi-Z  
48  
Hi-Z  
Tri-state  
14.318  
14.318  
TCLK  
14.318  
14.318  
14.318  
14.318  
48  
TCLK/2 TCLK/6 TCLK/3 TCLK/4  
Test mode(1)  
90.0  
30.0  
33.3  
30.0  
33.3  
60.0  
66.6  
60.0  
66.6  
48  
48  
48  
48  
133.3  
120.0  
100.0  
Notes:  
1. TCLK is a test clock driven on the X1 (crystal in pin) input during test mode.  
3
ICS9248-64  
I2C Command Bitmaps  
Byte 1: Reserved for Buffer  
Byte 0: Reserved for Buffer  
BIT PIN# PWD  
DESCRIPTION  
BIT PIN# PWD  
DESCRIPTION  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
-
-
-
-
-
-
-
-
1
1
1
1
1
1
1
1
(Reserved for Buffer)  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
-
-
-
-
-
-
-
-
1
1
1
1
1
1
1
1
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
Byte 3: Reserved for Buffer  
Byte 2: Reserved for Buffer  
BIT PIN# PWD  
DESCRIPTION  
BIT PIN# PWD  
DESCRIPTION  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
-
-
-
-
-
-
-
-
1
1
1
1
1
1
1
1
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
-
-
-
-
-
-
-
-
1
1
1
1
1
1
1
1
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
(Reserved for Buffer)  
4
ICS9248-64  
Byte 5: PCI Clock Control Register  
BIT PIN# PWD DESCRIPTION  
REF1 enable  
Byte 4: Clock Control Register  
BIT PIN# PWD  
DESCRIPTION  
REF0 enable  
7
6
5
4
3
2
1
0
2
1
1
1
1
1
1
1
1
7
6
5
4
3
1
1
1
1
1
1
17  
16  
14  
13  
11  
10  
8
PCICLK6 enable  
PCICLK5 enable  
PCICLK4 enable  
PCICLK3 enable  
PCICLK2 enable  
PCICLK1 enable  
PCICLK0 enable  
24  
23  
20  
19  
24MHz/48MHz enable  
48MHz enable  
AGP1 enable  
AGP0 enable  
CPUCLK2 enable (both of  
differential pair, True" and  
"Complimentary"  
CPUCLK1 enable (both of  
differential pair, True" and  
"Complimentary"  
CPUCLK0 enable (both of  
differential pair, True" and  
"Complimentary"  
2
1
0
42, 43  
39, 40  
36, 37  
1
1
1
Notes: A value of '1'b is enable, '0'b is disable  
Notes: A value of '1'b is enable, '0'b is disable  
Byte 6: SDRAM Clock & Generator Mode Control Register  
Bit  
Description  
PWD  
7
Spread Spectrum enable down spread  
1
Bit  
CPU  
PCI  
Spread Percentage  
654  
111  
110  
101  
100  
100  
120  
133  
90  
33.3  
30  
33.3  
30  
1% Down Spread  
1% Down Spread  
1% Down Spread  
-0.5%Down Spread  
6:4  
1
011 TCLK/2 TCLK/6 1% Down Spread  
010  
001  
000  
66  
50  
HI-Z  
33  
25  
HI-Z  
-0.5%Down Spread  
1% Down Spread  
1% Down Spread  
2:3  
1
0
(Reserved)  
1
1
1
I2C enable  
SDRAM_OUT Enable  
Notes: A value of '1'b is enable, '0'b is disable  
5
ICS9248-64  
Absolute Maximum Ratings  
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5V  
Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . GND 0.5 V to VDD +0.5 V  
Ambient Operating Temperature . . . . . . . . . . . . 0°C to +70°C  
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . 65°C to +150°C  
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are  
stress specifications only and functional operation of the device at these or any other conditions above those listed in the  
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended  
periods may affect product reliability.  
Electrical Characteristics - Input/Supply/Common Output Parameters  
TA = 0 - 70º C; Supply Voltage VDD = 3.3 V +/-5% (unless otherwise stated)  
PARAMETER  
Input High Voltage  
Input Low Voltage  
Input High Current  
Input Low Current  
Input Low Current  
SYMBOL  
CONDITIONS  
MIN  
2
TYP  
MAX UNITS  
VIH  
VDD+0.3  
V
V
VIL  
VSS-0.3  
0.8  
5
A
IIH  
VIN = VDD  
0.1  
2.0  
µ
µ
µ
A
A
IIL1  
VIN = 0 V; Inputs with no pull-up resistors  
VIN = 0 V; Inputs with pull-up resistors  
-5  
IIL2  
-200  
-100  
100  
110  
120  
IDD3.3OP66 CL = max cap loads; Select @ 66MHz  
IDD3.3OP100 CL = max cap loads; Select @ 100MHz  
IDD3.3OP133 CL = max cap loads; Select @ 133MHz  
PD  
Operating Supply  
Current  
180  
mA  
600  
16  
5
Power Down  
Input frequency  
95  
14.318  
A
µ
MHz  
Fi  
VDD = 3.3 V;  
12  
27  
CIN  
Logic Inputs  
pF  
Input Capacitance1  
Clk Stabilization1  
CINX  
TSTAB  
X1 & X2 pins  
36  
45  
3
pF  
From VDD = 3.3 V to 1% target Freq.  
VT = 50%  
ms  
ps  
tCPU-SDRAM  
tCPU-AGP  
190  
60  
250  
Skew1  
VT = 50%  
500  
ps  
1Guaranteed by design, not 100% tested in production.  
6
ICS9248-64  
Electrical Characteristics - 24_48M, REF(0:1)  
TA = 0 - 70º C; VDD = 3.3 V +/-5%; CL = 20 pF (unless otherwise stated)  
PARAMETER  
SYMBOL  
VOH5  
CONDITIONS  
MIN  
2.4  
TYP  
MAX UNITS  
V
Output High Voltage  
Output Low Voltage  
Output High Current  
Output Low Current  
IOH = -12 mA  
IOL = 9 mA  
VOH = 2.0 V  
VOL = 0.8 V  
2.8  
0.32  
-27  
22  
VOL5  
0.4  
-22  
V
IOH5  
mA  
mA  
IOL5  
16  
45  
Rise Time1  
Fall Time1  
Duty Cycle1  
tr5  
tf5  
VOL = 0.4 V, VOH = 2.4 V  
VOH = 2.4 V, VOL = 0.4 V  
2.3  
2.4  
4
4
ns  
ns  
dt5  
VT = 50%  
51  
55  
%
400  
1000  
ps  
VT = 1.5 Volts, REF  
VT = 1.5 Volts, USB, 24_48M  
Jitter, Cycle-to-cycle1  
tjcyc-cyc1  
260  
500  
ps  
1Guaranteed by design, not 100% tested in production.  
Electrical Characteristics - CPUCLK (Open Drain)  
TA = 0 - 70º C; VDD = 3.3 V +/-5%; CL = 20 pF (unless otherwise stated)  
PARAMETER  
Output Impedance  
SYMBOL  
ZO  
CONDITIONS  
VO = VX  
MIN  
TYP  
50  
MAX  
UNITS  
Termination to  
Vpull-up(external)  
Termination to  
Vpull-up(external)  
VOL = 0.3 V  
VOH2B  
Output High Voltage  
1
1.2  
0.4  
V
VOL2B  
IOL2B  
tr2B  
Output Low Voltage  
Output Low Current  
0.175  
21  
V
mA  
ns  
18  
Rise Time1  
VOL = 0.3 V, VOH = 1.2 V  
0.85  
0.9  
Differential voltage-  
AC1  
Differential voltage-  
DC1  
Vpullup(external)  
VDIF  
VDIF  
VX  
Note 2  
Note 2  
Note 3  
0.4  
0.2  
V
V
+ 0.6  
Vpullup(external)  
+ 0.6  
Differential Crossover  
550  
45  
750  
1100  
mV  
Voltage1  
Duty Cycle1  
dt2B  
tsk2B  
tsk2B  
VT = 50%  
VT = 50%  
VT = 50%  
51  
55  
%
ps  
ps  
Skew1, CPU to CPU  
100  
135  
250  
200  
Skew1, CPUT to CPUC  
Jitter, Cycle-to-cycle1  
tjcyc-cyc2B  
VT = VX  
110  
250  
ps  
Notes:  
1 - Guaranteed by design, not 100% tested in production.  
2 - VDIF specifies the minimum input differential voltages (VTR-VCP) required for switching, where VTR is the "true" input  
level and VCP is the "complement" input level.  
3 - Vpullup(external) = 1.5V, Min = Vpullup(external)/2-150mV; Max=(Vpullup(external)/2)+150mV  
7
ICS9248-64  
Electrical Characteristics - PCICLK(0:6)  
TA = 0 - 70º C; VDD = 3.3 V +/-5%; CL = 30 pF (unless otherwise stated)  
PARAMETER  
SYMBOL  
VOH1  
CONDITIONS  
MIN  
2.6  
TYP  
MAX UNITS  
V
Output High Voltage  
Output Low Voltage  
Output High Current  
Output Low Current  
IOH = -11 mA  
IOL = 9.4 mA  
VOH = 2.0 V  
VOL = 0.8 V  
3.1  
0.17  
-54  
44  
VOL1  
0.4  
-16  
V
IOH1  
mA  
mA  
IOL1  
19  
45  
Rise Time1  
Fall Time1  
Duty Cycle1  
Skew1(window)  
tr1  
tf1  
VOL = 0.4 V, VOH = 2.4 V  
VOH = 2.4 V, VOL = 0.4 V  
VT = 50%  
1.8  
1.65  
51  
2
2
ns  
ns  
%
ps  
dt1  
55  
500  
1
Tsk  
VT = 50%  
470  
Jitter, Cycle-to-cycle1  
tjcyc-cyc1  
120  
500  
ps  
VT = 1.5 Volts  
1Guaranteed by design, not 100% tested in production.  
Electrical Characteristics - PCICLK_F  
TA = 0 - 70º C; VDD = 3.3 V +/-5%; CL = 20 pF (unless otherwise stated)  
PARAMETER  
SYMBOL  
VOH1  
CONDITIONS  
MIN  
2.6  
TYP  
3.1  
MAX UNITS  
V
Output High Voltage  
Output Low Voltage  
Output High Current  
Output Low Current  
IOH = -11 mA  
IOL = 9.4 mA  
VOH = 2.0 V  
VOL = 0.8 V  
VOL1  
0.165  
-54  
0.4  
-12  
V
IOH1  
mA  
mA  
IOL1  
12  
45  
44  
Rise Time1  
Fall Time1  
Duty Cycle1  
tr1  
tf1  
VOL = 0.4 V, VOH = 2.4 V  
VOH = 2.4 V, VOL = 0.4 V  
VT = 50%  
1.75  
1.65  
51  
2
2
ns  
ns  
%
dt1  
55  
Jitter, Cycle-to-cycle1  
tjcyc-cyc1  
120  
500  
ps  
VT = 1.5 Volts  
1Guaranteed by design, not 100% tested in production.  
8
ICS9248-64  
Electrical Characteristics - AGP(0:1)  
TA = 0 - 70º C; VDD = 3.3 V +/-5%; CL = 20 pF (unless otherwise stated)  
PARAMETER  
SYMBOL  
VOH4B  
VOL4B  
CONDITIONS  
MIN  
2
TYP  
3
MAX UNITS  
V
Output High Voltage  
Output Low Voltage  
Output High Current  
Output Low Current  
IOH = -18 mA  
IOL = 18 mA  
VOH = 2.0 V  
VOL = 0.8 V  
0.31  
-63  
30  
0.4  
-19  
V
IOH4B  
mA  
mA  
IOL4B  
19  
45  
Rise Time1  
Fall Time1  
Duty Cycle1  
Tr4B  
Tf4B  
Dt4B  
VOL = 0.4 V, VOH = 2.0 V  
VOH = 2.0 V, VOL = 0.4 V  
VT = 50%  
1.3  
1.4  
50  
2
2
ns  
ns  
%
55  
Jitter, Cycle-to-cycle1  
tjcyc-cyc1  
290  
500  
ps  
VT = 1.5 Volts  
1Guaranteed by design, not 100% tested in production.  
Electrical Characteristics - SDRAM_OUT  
TA = 0 - 70º C; VDD = 3.3 V +/-5%, CL = 30 pF (unless otherwise stated)  
PARAMETER  
Output High Voltage  
Output Low Voltage  
Output High Current  
Output Low Current  
Rise Time1  
SYMBOL  
VOH3  
CONDITIONS  
MIN  
2
TYP  
3
MAX UNITS  
V
IOH = -11 mA  
IOL = 11 mA  
VOH = 2.0 V  
VOL = 0.8 V  
VOL3  
0.31  
-60  
30  
0.4  
-12  
V
mA  
mA  
ns  
IOH3  
IOL3  
12  
45  
1
Tr3  
VOL = 0.4 V, VOH = 2.4 V  
VOH = 2.4 V, VOL = 0.4 V  
VT = 50%  
1.7  
1.9  
55  
2.2  
2.2  
55  
Fall Time1  
Duty Cycle1  
1
Tf3  
ns  
1
Dt3  
%
Jitter, Cycle-to-cycle1  
tjcyc-cyc1  
130  
250  
ps  
VT = 1.5 Volts  
1Guarenteed by design, not 100% tested in production.  
9
ICS9248-64  
General I2C serial interface information  
The information in this section assumes familiarity with I2C programming.  
For more information, contact ICS for an I2C programming application note.  
How to Write:  
• Controller (host) sends a start bit.  
• Controller (host) sends the write address D2 (H)  
• ICS clock will acknowledge  
How to Read:  
• Controller (host) will send start bit.  
• Controller (host) sends the read address D3 (H)  
• ICS clock will acknowledge  
• Controller (host) sends a dummy command code  
• ICS clock will acknowledge  
• ICS clock will send the byte count  
• Controller (host) acknowledges  
• Controller (host) sends a dummy byte count  
• ICS clock will acknowledge  
• Controller (host) starts sending first byte (Byte 0)  
through byte 5  
• ICS clock sends first byte (Byte 0) through byte 5  
• Controller (host) will need to acknowledge each byte  
• Controller (host) will send a stop bit  
• ICS clock will acknowledge each byte one at a time.  
• Controller (host) sends a Stop bit  
How to Write:  
Controller (Host)  
ICS (Slave/Receiver)  
How to Read:  
Start Bit  
Controller (Host)  
ICS (Slave/Receiver)  
Address  
Start Bit  
D2(H)  
Address  
D3(H)  
ACK  
ACK  
ACK  
ACK  
ACK  
ACK  
ACK  
ACK  
ACK  
Dummy Command Code  
ACK  
Byte Count  
Dummy Byte Count  
Byte 0  
ACK  
ACK  
ACK  
ACK  
ACK  
ACK  
Byte 0  
Byte 1  
Byte 2  
Byte 3  
Byte 4  
Byte 5  
Byte 1  
Byte 2  
Byte 3  
Byte 4  
Byte 5  
ACK  
Stop Bit  
Stop Bit  
Notes:  
1.  
The ICS clock generator is a slave/receiver, I2C component. It can read back the data stored in the latches for  
verification. Read-Back will support Intel PIIX4 "Block-Read" protocol.  
2.  
3.  
4.  
5.  
The data transfer rate supported by this clock generator is 100K bits/sec or less (standard mode)  
The input is operating at 3.3V logic levels.  
The data byte format is 8 bit bytes.  
To simplify the clock generator I2C interface, the protocol is set to use only "Block-Writes" from the controller. The  
bytes must be accessed in sequential order from lowest to highest byte with the ability to stop after any complete byte  
has been transferred. The Command code and Byte count shown above must be sent, but the data is ignored for those  
two bytes. The data is loaded until a Stop sequence is issued.  
6.  
At power-on, all registers are set to a default condition, as shown.  
10  
ICS9248-64  
Shared Pin Operation -  
Input/Output Pins  
Figure 1 shows a means of implementing this function when  
a switch or 2 pin header is used. With no jumper is installed  
the pin will be pulled high. With the jumper in place the pin  
will be pulled low. If programmability is not necessary, than  
only a single resistor is necessary.The programming resistors  
should be located close to the series termination resistor to  
minimize the current loop area. It is more important to locate  
the series termination resistor close to the driver than the  
programmingresistor.  
The I/O pins designated by (input/output) on the ICS9248-  
64 serve as dual signal functions to the device. During initial  
power-up, they act as input pins. The logic level (voltage)  
that is present on these pins at this time is read and stored  
into a 5-bit internal data latch. At the end of Power-On reset,  
(seeAC characteristics for timing values), the device changes  
the mode of operations for these pins to an output function.  
In this mode the pins produce the specified buffered clocks  
to external loads.  
To program (load) the internal configuration register for these  
pins, a resistor is connected to either the VDD (logic 1) power  
supply or the GND (logic 0) voltage potential. A 10 Kilohm  
(10K) resistor is used to provide both the solid CMOS  
programming voltage needed during the power-up  
programming period and to provide an insignificant load on  
the output clock during the subsequent operating period.  
Via to  
VDD  
Programming  
Header  
2K W  
Via to Gnd  
Device  
Pad  
8.2K W  
Clock trace to load  
Series Term. Res.  
Fig. 1  
11  
ICS9248-64  
PD# Timing Diagram  
The power down selection is used to put the part into a very low power state without turning off the power to the part. PD# is  
an asynchronous active low input. This signal needs to be synchronized internal to the device prior to powering down the  
clock synthesizer.  
Internal clocks are not running after the device is put in power down. When PD# is active low all clocks need to be driven to  
a low value and held prior to turning off the VCOs and crystal. The power up latency needs to be less than 3 mS. The power  
down latency should be as short as possible but conforming to the sequence requirements shown below. PCI_STOP# and  
CPU_STOP# are considered to be don't cares during the power down operations. The REF and 48MHz clocks are expected to  
be stopped in the LOW state as soon as possible. Due to the state of the internal logic, stopping and holding the REF clock  
outputs in the LOW state may require more than one clock cycle to complete.  
PD#  
CPUCLKT  
CPUCLKC  
PCICLK  
VCO  
Crystal  
Notes:  
1. All timing is referenced to the Internal CPUCLK (defined as inside the ICS9248-64 device).  
2. As shown, the outputs Stop Low on the next falling edge after PD# goes low.  
3. PD# is an asynchronous input and metastable conditions may exist. This signal is synchronized inside this part.  
4. The shaded sections on the VCO and the Crystal signals indicate an active clock.  
5. Diagrams shown with respect to 133MHz. Similar operation when CPU is 100MHz.  
12  
ICS9248-64  
CPU_STOP# Timing Diagram  
CPU_STOP# is an asychronous input to the clock synthesizer. It is used to turn off the CPUCLKs for low power operation.  
CPU_STOP# is synchronized by the ICS9248-64. All other clocks will continue to run while the CPUCLKs clocks are  
disabled. The CPUCLKs will always be stopped in a low state and start in such a manner that guarantees the high pulse width  
is a full pulse. CPUCLK on latency is less than 4 CPUCLKs and CPUCLK off latency is less than 4 CPUCLKs.  
INTERNAL  
CPUCLK  
PCICLK  
CPU_STOP#  
PCI_STOP# (High)  
PD# (High)  
CPUCLKT  
CPUCLKC  
Notes:  
1. All timing is referenced to the internal CPUCLK.  
2. CPU_STOP# is an asynchronous input and metastable conditions may exist.  
This signal is synchronized to the CPUCLKs inside the ICS9248-64.  
3. All other clocks continue to run undisturbed including SDRAMR.  
4. PD# and PCI_STOP# are shown in a high (true) state.  
13  
ICS9248-64  
PCI_STOP# Timing Diagram  
PCI_STOP# is an asynchronous input to the ICS9248-64. It is used to turn off the PCICLK clocks for low power operation.  
PCI_STOP# is synchronized by the ICS9248-64 internally. PCICLK clocks are stopped in a low state and started with a full  
high pulse width guaranteed. PCICLK clock on latency cycles are only one rising PCICLK clock off latency is one PCICLK  
clock.  
CPUCLK  
(Internal)  
PCICLK  
(Internal)  
PCICLK  
(Free-running)  
CPU_STOP#  
PCI_STOP#  
PWR_DWN#  
PCICLK  
(External)  
Notes:  
1. All timing is referenced to the Internal CPUCLK (defined as inside the ICS9248 device.)  
2. PCI_STOP# is an asynchronous input, and metastable conditions may exist. This signal is required to be synchronized  
inside the ICS9248.  
3. All other clocks continue to run undisturbed.  
4. PD# and CPU_STOP# are shown in a high (true) state.  
14  
ICS9248-64  
In Millimeters  
In Inches  
c
N
SYMBOL COMMON DIMENSIONS COMMON DIMENSIONS  
MIN  
2.41  
0.20  
0.20  
0.13  
MAX  
2.80  
0.40  
0.34  
0.25  
MIN  
.095  
.008  
.008  
.005  
MAX  
.110  
.016  
.0135  
.010  
L
A
A1  
b
E1  
E
INDEX  
AREA  
c
D
E
E1  
e
SEE VARIATIONS  
SEE VARIATIONS  
10.03  
7.40  
10.68  
7.60  
.395  
.291  
.420  
.299  
1
2
a
hh xx 4455°°  
0.635 BASIC  
0.025 BASIC  
D
h
L
0.38  
0.50  
0.64  
1.02  
.015  
.020  
.025  
.040  
N
SEE VARIATIONS  
SEE VARIATIONS  
A
0°  
8°  
0°  
8°  
α
A1  
VARIATIONS  
- CC --  
D mm.  
D (inch)  
N
e
SEATING  
PLANE  
MIN  
15.75  
MAX  
16.00  
MIN  
.620  
MAX  
b
48  
.630  
.10 (.004)  
C
Reference Doc.: JEDEC Publication 95, MO-118  
10-0034  
300 mil SSOP Package  
Ordering Information  
ICS9248yF-64  
Example:  
ICS XXXX y F - PPP  
Pattern Number (2 or 3 digit number for parts with ROM code patterns)  
Package Type  
F=SSOP  
Revision Designator (will not correlate with datasheet revision)  
Device Type  
Prefix  
ICS, AV = Standard Device  
ICS reserves the right to make changes in the device data identified in  
this publication without further notice. ICS advises its customers to  
obtain the latest version of all device data to verify that any  
15  
information being relied upon by the customer is current and accurate.  

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