ICS94211AFLF Datasheet, PDF (1/17 Pages) Integrated Device Technology – 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
*PCI_STOP/REF0
2
GND
3
X1
4
X2
5
VDDPCI
6
*MODE/PCICLK_F
7
**FS3/PCICLK0
8
GND
9
PCICLK1
10
PCICLK2
11
PCICLK3
12
PCICLK4
13
VDDPCI
14
BUFFER_IN
15
GND
16
SDRAM12_F
17
SDRAM11
18
VDDSDR
19
SDRAM10
20
SDRAM9
21
GND
22
SDATA
23
SCLK
24
48
VDDLAPIC
47
IOAPIC
46
REF1/FS2*
45
GND
44
CPUCLK0
43
CPUCLK1
42
VDDLCPU
41
RESET#
40
SDRAM0
39
GND
38
SDRAM1
37
SDRAM2
36
VDDSDR
35
SDRAM3
34
SDRAM4
33
GND
32
SDRAM5
31
SDRAM6
30
VDDSDR
29
SDRAM7
28
SDRAM8
27
VDD48
26
48MHz/FS0*
25
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
Block Diagram
X1
X2
BUFFER IN
PLL2
XTAL
OSC
PLL1
Spread
Spectrum
FS(3:0) ⁴
MODE
PCI_STOP#
SDATA
SCLK
Control
Logic
Config.
Reg.
/2
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
0
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
0
1
0
0
1
0
1
1
0
1
1
1
0
1
1
0
1
1
1
1
1
1
FS0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
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
0441F—08/24/05