ICS94211 Datasheet, PDF (1/16 Pages) Integrated Circuit Systems – Programmable System Frequency Generator for PII/III™

Integrated
Circuit
Systems, Inc.
ICS94211
Programmable System Frequency Generator for PII/III™
Recommended Application:
440BX/VIA Apollo Pro133/ ALI 1631 style chipset.
Output Features:
• 2 - CPUs @2.5V
• 1 - IOAPIC @ 2.5V
• 13 - SDRAM @ 3.3V
• 6 - PCI @3.3V,
• 1 - 48MHz, @3.3V
• 1 - 24MHz @ 3.3V
• 2 - REF @3.3V, 14.318MHz.
Features:
• Programmable ouput frequency.
• Programmable ouput rise/fall time.
• Programmable PCICLK, PCICLK_F,
SDRAM 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.
• FS pins for frequency select
Pin Configuration
VDDREF
1
48
*PCI_STOP/REF0
2
47
GND
3
46
X1
4
45
X2
5
44
VDDPCI
6
43
*MODE/PCICLK_F
7
42
**FS3/PCICLK0
8
41
GND
9
40
PCICLK1
10
39
PCICLK2
11
38
PCICLK3
12
37
PCICLK4
13
36
VDDPCI
14
35
BUFFER_IN
15
34
GND
16
33
SDRAM12
17
32
SDRAM11
18
31
VDDSDR
19
30
SDRAM10
20
29
SDRAM9
21
28
GND
22
27
SDATA
23
26
SCLK
24
25
VDDL
IOAPIC
REF1/FS2*
GND
CPUCLK0
CPUCLK1
VDDLCPU
RESET#
SDRAM0
GND
SDRAM1
SDRAM2
VDDSDR
SDRAM3
SDRAM4
GND
SDRAM5
SDRAM6
VDDSDR
SDRAM7
SDRAM8
VDD48
48MHz/FS0*
24MHz/FS1*
48-Pin 300mil SSOP
* Internal Pull-up Resistor of 120K to VDD
** Internal Pull-down resistor of 120K to GND
Key Specifications:
• CPU – CPU: <175ps
• SDRAM - SDRAM: <500ps
• PCI – PCI: <500ps
• CPU(early)-PCI: Min=1.0ns, Typ=2.0ns, Max=4.0ns
X1
X2
BUFFER IN
FS(3:0) ⁴
MODE
PCI_STOP#
SDATA
SCLK
Block Diagram
PLL2
/2
XTAL
OSC
PLL1
Spread
Spectrum
Control
Logic
Config.
Reg.
PCI
CLOCK
DIVDER
STOP
48MHz
24MHz
IOAPIC
2 ^REF(1:0)
13 ^{SDRAM (12:0)}
2 ^{CPUCLK (1:0)}
PCICLK (4:0)
5
PCICLK_F
RESET#
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
66.82
103.00
112.01
68.01
100.23
120.00
114.99
109.99
105.00
140.00
150.00
124.00
132.99
PCICLK
(MHz)
40.00
37.50
41.65
33.41
34.33
37.34
34.01
33.41
40.00
38.33
36.66
35.00
35.00
37.50
31.00
33.25
94211 Rev A 03/28/01
ICS reserves the right to make changes in the device data identified in
this publication without further notice. ICS advises its customers to
obtain the latest version of all device data to verify that any
information being relied upon by the customer is current and accurate.