ICS94228 Datasheet, PDF (1/17 Pages) Integrated Circuit Systems – Programmable System Clock Chip for AMD - K7™ processor

Integrated
Circuit
Systems, Inc.
ICS94228
Programmable System Clock Chip for AMD - K7™ processor
Recommended Application:
VIA KT266 style chipset
Output Features:
• 1 - Differential pair open drain CPU clocks @ 2.7V
• 1 - Differential pair push-pull CPU clocks @ 2.5V
• 11 - PCI including 1 free running and 1 early @ 3.3V
• 1 - 48MHz, @ 3.3V fixed
• 1 - 24/48MHz @ 3.3V
• 3 - REF @ 3.3V, 14.318MHz.
Features:
• Programmable output frequency.
• Programmable output rise/fall time.
• Programmable slew and skew control for CPUCLK,
PCICLK, AGP, REF, 48MHz and 24_48MHz.
• 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:
• CPU - CPU: <200ps
• PCI - PCI: <500ps
• CPU (early - PCI: min=1.0ns, max=2.6ns
• CPU cycle to cycle jitter: <250ps
Pin Configuration
VDDREF
1
GND
2
X1
3
X2
4
AVDD48
5
*FS2/48MHz
6
*FS3/24_48MHz
7
GND
8
PCICLK_F
9
*SEL24_48#/PCICLK0
10
PCICLK1
11
GND
12
PCICLK2
13
PCICLK3
14
VDDPCI
15
PCICLK4
16
PCICLK5
17
PCICLK6
18
GND
19
PCICLK7
20
PCILCK8
21
PCICLK9_E
22
VDDPCI
23
SRESET#
24
48
REF0/FS0*
47
REF1/FS1*
46
REF_F
45
REF_STOP#*
44
AGP_STOP#*
43
GND
42
CPUCLKT0
41
CPUCLKC0
40
VDDL
39
CPUCLK_CST0
38
CPUCLK_CSC0
37
GND
36
CPU_STOP#*
35
PCI_STOP#*
34
PD#*
33
AVDD
32
AGND
31
SDATA
30
SCLK
29
GND
28
AGP2
27
AGP1
26
AGP0
25
VDDAGP
48-Pin 300mil SSOP
* Internal Pull-up Resistor of 120K to VDD
Block Diagram
PLL2
X1
XTAL
X2
OSC
PLL1
Spread
Spectrum
SEL24_48#
SDATA
SCLK
FS (3:0)
PD#
PCI_STOP#
CPU_STOP#
AGP_STOP#
REF_STOP#
Control
Logic
Config.
Reg.
/2
CPU
DIVDER
CPU
DIVDER
Stop
Stop
PCI
DIVDER
Stop
AGP
DIVDER
Stop
48MHz (1:0)
2
24_48MHz
2 ^{REF (1:0)}
REF_F
CPUCLKT0
CPUCLKC0
CPUCLK_CST0
CPUCLK_CSC0
PCICLK9_E
9 ^{PCICLK (8:0)}
PCICLK_F
AGP (2:0)
3
SRESET#
Functionality
FS3 FS2 FS1 FS0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
CPU
(MHz)
233.33
220.00
210.00
200.00
190.00
180.00
170.00
150.00
140.00
120.00
110.00
66.67
200.00
166.67
100.00
133.33
AGP
(MHz)
77.78
73.33
70.00
66.67
76.00
72.00
68.00
75.00
70.00
60.00
66.00
66.67
66.67
66.67
66.67
66.67
PCICLK
(MHz)
38.88
36.67
35.00
33.33
38.00
36.00
34.00
37.50
35.00
30.00
33.00
33.33
33.33
33.33
33.33
33.33
0447E—05/07/04