ICS94241 Datasheet, PDF (1/16 Pages) Integrated Circuit Systems – Programmable TCH™ for Differential PIII™ Processor

Integrated
Circuit
Systems, Inc.
ICS94241
Programmable TCH™ for Differential PIII™ Processor
Recommended Application:
VIA PL133-T style chipset with Intel differential PIII
processor
Output Features:
• 2 - CPUs @2.5V
• 13 - SDRAM @ 3.3V
• 7 - 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 output to output skew
• Programmable spread spectrum for EMI control
• Real time system reset output
• Watchdog timer technology to reset system
if over-clocking causes malfunction
• Uses external 14.318MHz crystal
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
Pin Configuration
VDDREF
1
GNDREF
2
X1
3
X2
4
VDDPCI
5
*FS4/PCICLK0
6
*FS3/PCICLK1
7
GNDPCI
8
PCICLK2
9
PCICLK3
10
PCICLK4
11
PCICLK5
12
PCICLK6
13
VDDPCI
14
BUFFER_IN
15
GNDSDR
16
SDRAM12
17
SDRAM11
18
VDDSDR
19
SDRAM10
20
SDRAM9
21
GND48
22
SDATA
23
SCLK
24
48
VTT_PWRGD#
47
REF0
46
REF1/FS2**¹
45
GNDCPU
44
CPUCLK_CS
43
CPUCLK0
42
VDDLCPU
41
RESET#
40
SDRAM0
39
GNDSDR
38
SDRAM1
37
SDRAM2
36
VDDSDR
35
SDRAM3
34
SDRAM4
33
GNDSDR
32
SDRAM5
31
SDRAM6
30
VDDSDR
29
SDRAM7
28
SDRAM8
27
AVDD48
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
1. This output has 1.5 to 2X drive strength
Block Diagram
0453C—10/26/04
Functionality
Bit2 Bit7 Bit6 Bit5 Bit4 _{CPUCLK PCICLK Spread Percentage}
FS4 FS3 FS2 FS1 FS0
0 0 0 0 0 66.67 33.33 +/- 0.25 Center Spread
0 0 0 0 1 66.67 33.33 0 to -0.5% Down Spread
0 0 0 1 0 68.67 34.33 ± 0.25 Center Spread
0 0 0 1 1 71.34 35.66 +/- 0.25 Center Spread
0 1 0 0 0 100.00 33.33 +/- 0.25 Center Spread
0 1 0 0 1 100.00 33.33 0 to -0.5% Down Spread
0 1 0 1 0 103.00 34.33 +/- 0.25 Center Spread
0 1 0 1 1 107.00 35.67 +/- 0.25 Center Spread
1 0 0 0 0 200.00 33.33 +/- 0.25 Center Spread
1 0 0 0 1 200.00 33.33 0 to -0.5% Down Spread
1 0 0 1 0 206.00 34.33 +/- 0.25 Center Spread
1 0 0 1 1 214.00 35.67 +/- 0.25 Center Spread
1 1 0 0 0 133.33 33.33 +/- 0.25 Center Spread
1 1 0 0 1 133.33 33.33 0 to -0.5% Down Spread
1 1 0 1 0 137.33 34.33 +/- 0.25 Center Spread
1 1 0 1 1 142.67 35.67 +/- 0.25 Center Spread
For additional margin testing frequencies refer to pg 5
frequency table.