ICS94225 Datasheet, PDF (1/18 Pages) Integrated Circuit Systems – AMD-K7TM System Clock Chip

Integrated
Circuit
Systems, Inc.
ICS94225
AMD-K7^TM System Clock Chip
Recommended Application:
AMD 750/760 style chipset
Output Features:
• 3 differential pair open drain CPU clocks (1.5V
external
pull-up; up to 150MHz achieviable through I²C)
• 2 - AGPCLK @ 3.3V
• 8 - PCI @3.3V, including 1 free running
• 1 - 48MHz @ 3.3V
• 1 - 24/48MHz @ 3.3V
• 2- REF @3.3V, 14.318MHz.
Features:
• Programmable ouput frequency
• Programmable ouput rise/fall time
• Programmable group skew
• Real time system reset output
• Spread spectrum for EMI control typically
by 7dB to 8dB,
with programmable spread percentage
• Watchdog timer technology to reset system
if over-clocking causes malfunction
• Uses external 14.318MHz crystal
Pin Configuration
**FS0/REF0
1
**FS1/REF1
2
GNDREF
3
X1
4
X2
5
GNDPCI
6
PCICLK_F
7
PCICLK0
8
VDDPCI
9
PCICLK1
10
PCICLK2
11
GNDPCI
12
PCICLK3
13
PCICLK4
14
VDDPCI
15
PCICLK5
16
PCICLK6
17
VDDAGP
18
AGP0
19
AGP1
20
GNDAGP
21
VDD48
22
48MHz
23
SEL24_48#/24-48MHz
24
48
VDDREF
47
GNDSD
46
SDRAM_OUT
45
VDDSD
44
RESERVED
43
CPUCLKC2
42
CPUCLKT2
41
GNDCPU
40
CPUCLKC1
39
CPUCLKT1
38
GND
37
CPUCLKC0
36
CPUCLKT0
35
RESET#
34
VDD
33
GND
32
PCI_STOP#
31
CPU_STOP#
30
PD#
29
SPREAD#
28
FS2*
27
SDATA
26
SCLK
25
GND48
48-Pin 300mil SSOP
* Internal 120K pullup resistor on indicated inputs
** Internal 240K pullup resistor on indicated inputs
Block Diagram
PLL2
X1
XTAL
X2
OSC
PLL1
Spread
Spectrum
SEL24_48#
SDATA
SCLK
FS (2:0)
PD#
PCI_STOP#
CPU_STOP#
SPREAD#
Control
Logic
Config.
Reg.
0445B—08/01/03
/2
CPU
DIVDER
Stop
SDRAM
DIVDER
PCI
DIVDER
Stop
AGP
DIVDER
48MHz
24_48MHz
REF (1:0)
3 ^{CPUCLKT (2:0)}
3 ^{CPUCLKC (2:0)}
SDRAM_OUT
PCICLK (6:0)
7
PCICLK_F
AGP (1:0)
2
Functionality
FS2 FS1 FS0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
CPU,
SDRAM
133.33
95
100.99
115
100.7
103
105
110
Power Groups
VDD48, GND48 = 48MHz, PLL2
VDDREF, GNDREF= REF, X1, X2
VDD, GND = PLL Core
PCI
33.33
31.67
33.66
38.33
33.57
34.33
35.00
36.67
AGP
66.67
63.33
67.33
76.67
67.13
68.67
70.00
73.33