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Integrated
Circuit
Systems, Inc.
ICS952003
Preliminary Product Review
Block Diagram
0488B—04/09/02
Pin Configuration
Recommended Application:
SIS 645/650 style chipsets.
Output Features:
2 - Pairs of differential CPUCLKs (differential current mode)
1 - SDRAM @ 3.3V
8 - PCI @3.3V
2 - AGP @ 3.3V
2 - ZCLKs @ 3.3V
1- 48MHz, @3.3V fixed.
1- 24/48MHz, @3.3V selectable by I
2
C
(Default is 24MHz)
3- REF @3.3V, 14.318MHz.
Features/Benefits:
Selectable asynchronous/synchronous SDRAM, AGP,
ZCLK and PCI outputs
Programmable output frequency, divider ratios, output rise/
falltime, output skew.
Programmable spread percentage for EMI control.
Watchdog timer technology to reset system
if system malfunctions.
Programmable watch dog safe frequency.
Support I
2
C Index read/write and block read/write
operations.
For PC133 SDRAM system use the ICS9179-16 as the
memory buffer.
For DDR SDRAM system use the ICS93705 or
ICS93722 as the memory buffer.
Uses external 14.318MHz crystal.
Key Specifications:
PCI - PCI output skew: < 500ps
CPU - SDRAM output skew: < 1ns
AGP - AGP output skew: <150ps
Functionality
Programmable Timing Control Hub for P
4
processor
* These inputs have a 120K pull up to VDD.
** These inputs have a 120K pull down to GND.
48-Pin 300-mil SSOP
Power Groups
VDDCPU = CPU
VDDPCI = PCICLK_F, PCICLK
VDDSD = SDRAM
AVDD48 = 48MHz, 24MHz, fixed PLL
AVDD = Analog Core PLL
VDDAGP= AGP
VDDREF = Xtal, REF
VDDZ = ZCLK
Note: For additional margin testing frequencies, refer to Byte 4
Bit 2 Bit 7 Bit 6 Bit 5 Bit 4
CPU
SDRAM ZCLK
AGP
PCI
FS4 FS3 FS2 FS1 FS0 (MHz)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
1
0
0
1
0
0
1
0
1
0
0
1
0
0
1
0
0
1
0
0
1
1
0
1
1
0
1
1
0
1
1
(MHz)
66.67
100.00
200.00
133.33
150.00
125.00
160.00
133.33
200.00
166.67
166.67
133.33
133.33
95.00
126.67
66.67
(MHz)
66.67
66.67
66.67
66.67
60.00
62.50
66.67
80.00
66.67
62.50
71.43
66.67
66.67
63.33
63.33
50.00
(MHz)
66.67
66.67
66.67
66.67
60.00
62.50
66.67
66.67
66.67
62.50
83.33
66.67
66.67
63.33
63.33
50.00
(MHz)
33.33
33.33
33.33
33.33
30.00
31.25
33.33
33.33
33.33
31.25
41.67
33.33
33.33
31.67
31.67
25.00
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
66.67
100.00
100.00
100.00
100.00
100.00
100.00
100.00
100.00
100.00
100.00
80.00
80.00
95.00
95.00
66.67
VDDREF
FS0/REF0
*FS1/REF1
**FS2/REF2
GNDREF
X1
X2
GNDZ
ZCLK0
ZCLK1
VDDZ
VDDPCI
PCICLK0
PCICLK1
GNDPCI
VDDPCI
PCICLK2
PCICLK3
PCICLK4
PCICLK5
GNDPCI
**
*
*PCI_STOP#
**FS3/PCICLK_F0
**FS4/PCICLK_F1
VDDSD
SDRAM
GNDSD
CPU_STOP#
CPUCLKT_1
CPUCLKC_1
VDDCPU
GNDCPU
CPUCLKT_0
CPUCLKC_0
IREF
GNDA
VDDA
SCLK
SDATA
PD#*/Vtt_PWRGD
GNDAGP
AGPCLK0
AGPCLK1
VDDAGP
VDDA48
48MHz
24_48MHz/MULTISEL
GND48
*
*
I
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
I REF
CPU
DIVDER
PLL2
PLL1
Spread
Spectrum
48MHz
24_48MHz
ZCLK (1:0)
PCICLK (9:0)
AGP (1:0)
PCICLK_F (1:0)
2
2
2
6
2
X1
X2
XTAL
OSC
ZCLK
DIVDER
PCI
DIVDER
Stop
SDATA
SCLK
FS (4:0)
PD#
PCI_STOP#
CPU_STOP#
MULTISEL
PD#/Vtt_PWRGD
Control
Logic
Config.
Reg.
/ 2
REF (1:0)
AGP
DIVDER
SDRAM
SDRAM
Stop
2
2
CPUCLKT (1:0)
CPUCLKC (1:0)
PRODUCT PREVIEW
documents contain information on new products in the sampling or preproduction phase of development. Characteristic data and other specifications are subject to
change without notice.