ICS94222 Datasheet, PDF (1/19 Pages) List of Unclassifed Manufacturers – Programmable System Frequency Generator for PII/III™

Integrated
Circuit
Systems, Inc.
ICS94222
Advance Information
Programmable System Frequency Generator for PII/III™
Recommended Application:
BX, Appollo Pro 133 type of chip set.
Output Features:
• 3 - CPUs @2.5V, up to 166MHz.
• 17 - SDRAM @ 3.3V, up to 166MHz.
• 7 - PCI @3.3V
• 2 - IOAPIC @ 2.5V
• 1 - 48MHz, @3.3V fixed.
• 1 - 24MHz @ 3.3V
• 2 - REF @3.3V, 14.318MHz.
Features:
• Programmable ouput frequency.
• Programmable ouput rise/fall time.
• Programmable PCI_F and PCICLK skew.
• 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.
• FS pins for frequency select
Pin Configuration
AVDD
1
*FS2/REF1
2
*PCI_STOP#/REF0
3
GND
4
X1
5
X2
6
VDD
7
*MODE/PCICLK_F
8
*FS3/PCICLK0
9
GND
10
PCICLK1
11
PCICLK2
12
PCICLK3
13
PCICLK4
14
VDD
15
PCICLK5
16
BUFFERIN
17
SDRAM11
18
SDRAM10
19
VDD
20
SDRAM9
21
SDRAM8
22
GND
23
SDRAM15
24
SDRAM14
25
GND
26
SDATA
27
SCLK
28
56
VDDL
55
IOAPIC0
54
IOAPIC_F
53
GND
52
CPUCLK_F
51
CPUCLK0
50
VDDL
49
CPUCLK1
48
GND
47
CLK_STOP*
46
SDRAM_F
45
VDDSDR
44
SDRAM0
43
SDRAM1
42
GND
41
SDRAM2
40
SDRAM3
39
SDRAM4
38
SDRAM5
37
VDD
36
SDRAM6
35
SDRAM7
34
GND
33
SDRAM12
32
SDRAM13
31
AVDD48
30
24MHz/FS0*
29
48MHz/FSI*¹
Key Specifications:
• CPU – CPU: <175ps
• SDRAM - SDRAM: <500ps
• PCI – PCI: <500ps
• CPU-SDRAM: <500ps
• CPU(early)-PCI: Min=1.0ns, Typ=2.0ns, Max=4.0ns
56-Pin SSOP
* Internal Pull-up Resistor of 240K to 3.3V on indicated inputs
Block Diagram
PLL2
÷2
X1
XTAL
X2
OSC
STOP
FS (3:0)
MODE
CLK_STOP#
PCI_STOP#
SCLK
SDATA
BUFFERIN
PLL1
Spread
Spectrum
LATCH
POR
Control
Logic
Config.
Reg.
STOP
PCI
CLOCK
DIVDER
STOP
STOP
48MHz
24MHz
IOAPIC_F
IOAPIC0
REF [1:0]
2
CPUCLK_F
1
CPUCLK (1:0)
6 ^{PCICLK (5:0)}
PCICLK_F
16 ^{SDRAM (15:0)}
SDRAM_F
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)
80.00
75.00
83.31
66.9
103.00
112.01
68.01
100.7
120.00
114.99
109.99
105.00
140.00
150.00
124.00
133.9
PCICLK
(MHz)
40.00
37.50
41.65
33.45
34.33
37.34
34.01
33.57
40.00
38.33
36.66
35.00
35.00
37.50
31.00
33.25
94222 Rev - 5/10/01
This document is confidential and should not be released
without written consents from ICS.
ADVANCE INFORMATION documents contain information on products in the
formative or design phase development. Characteristic data and other
specifications are design goals. ICS reserves the right to change or discontinue
these products without notice.