ICS94235 Datasheet, PDF (1/19 Pages) Integrated Circuit Systems – PROGRAMMABLE SYSTEM CLOCK CHIP FOR AMD-K7 TM PROCESSOR

Integrated
Circuit
Systems, Inc.
ICS94235
Recommended Application:
Output Features:
• 1 - Differential pair open drain CPU clocks
• 1 - Single-ended open drain CPU clock
• 13 - SDRAM @ 3.3V
• 7 - PCI @ 3.3V
• 2 - AGP @ 3.3V
• 1 - 48MHz, @3.3V
• 1 - REF @ 3.3V, (selectable strength) through I²C
Features:
• Programmable ouput frequency
• Programmable ouput rise/fall time
• Programmable CPU, SDRAM, PCI and AGP 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
Skew Specifications:
• CPUT - CPUC: <250ps
• PCI - PCI: <500ps
• CPU - SDRAM: <350ps
• SDRAM - SDRAM: <250ps
• AGP - AGP: <250ps
• AGP - PCI: <750ps
• CPU - PCI: <3ns
Pin Configuration
RESET#
1
*PD#
2
GND
3
X1
4
X2
5
AVDD
6
**FS0/REF0
7
VDD
8
**FS1/AGP0
9
AGP1
10
GND
11
*FS2/PCICLK_F
12
PCICLK0
13
PCICLK1
14
PCICLK2
15
GND
16
VDD
17
*MODE/PCICLK3
18
PCICLK4
19
PCICLK5
20
AVDD48
21
**FS3/48MHz
22
GND
23
SCLK
24
48
GND
47
CPUCLKT0
46
CPUCLKC0
45
CPUCLKT1
44
SDATA
43
SDRAM0
42
SDRAM1
41
GND
40
VDD
39
SDRAM2
38
SDRAM3
37
SDRAM4
36
SDRAM5
35
VDD
34
GND
33
SDRAM6
32
SDRAM7
31
SDRAM8
30
SDRAM9
29
GND
28
VDD
27
SDRAM10(PCI_STOP#)*
26
SDRAM11
25
SDRAM12
48-Pin 300mil SSOP &
240mil TSSOP package
Block Diagram
PLL2
X1
XTAL
X2
OSC
PLL1
Spread
Spectrum
SDATA
SCLK
FS (3:0)
PD#
PCI_STOP#
MODE
Control
Logic
Config.
Reg.
CPU
DIVDER
SDRAM
DIVDER
Stop
PCI
DIVDER
Stop
AGP
DIVDER
Stop
48MHz
REF0
CPUCLKT (1:0)
2
CPUCLKC0
SDRAM (12:0)
13
PCICLK (5:0)
6
PCICLK_F
AGP (1:0)
2
RESET#
Functionality
FS3
0
0
0
0
0
0
0
0
1
1
1
1
1
0
1
1
FS2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
FS1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Power Groups
FS0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
CPU SDRAM
66.66 66.66
66.66 100.00
100.00 66.66
100.00 100.00
100.00 133.33
120.00 120.00
133.33 100.00
133.33 133.33
90.00 90.00
100.90 100.90
100.00 66.66
100.00 100.00
100.00 133.33
126.00 126.00
133.33 100.00
133.33 133.33
PCI
33.33
33.33
33.33
33.33
33.33
30.00
33.33
33.33
30.00
33.63
33.33
33.33
33.33
31.50
33.33
33.33
AGP
66.66
66.66
66.66
66.66
66.66
60.00
66.66
66.66
60.00
67.27
66.66
66.66
66.66
63.00
66.66
66.66
94235 Rev A 01/17/02
Third party brands and names are the property of their respective owners.