ICS94241 Datasheet, PDF (8/16 Pages) Integrated Circuit Systems – Programmable TCH™ for Differential PIII™ Processor

ICS94241
Byte 13: Spread Sectrum Control Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
X Spread Spectrum Bit7
X Spread Spectrum Bit6
X Spread Spectrum Bit5
X Spread Spectrum Bit4
X Spread Spectrum Bit3
X Spread Spectrum Bit2
X Spread Spectrum Bit1
X Spread Spectrum Bit0
Note: Please utilize software utility provided by ICS
Application Engineering to configure spread
spectrum. Incorrect spread percentage may cause
system failure.
Byte 15: Output Skew Control
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
0
1
1
PCICLK0 Skew Control
0
0
1
1
PCICLK (6:1) Skew Control
0
Byte 14: Spread Sectrum Control Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
X Reserved
X Reserved
X Reserved
X Spread Spectrum Bit12
X Spread Spectrum Bit11
X Spread Spectrum Bit10
X Spread Spectrum Bi 9
X Spread Spectrum Bit8
Note: Please utilize software utility provided by ICS
Application Engineering to configure spread
spectrum. Incorrect spread percentage may cause
system failure.
Byte 16: Output Skew Control
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
0
0
SDRAM (12:1) Skew Control
0
0
CPUCLK_CS Skew Control
0
0
CPUCLK0 Skew Control
0
0
SDRAM0 Skew Control
Byte 17: Output Rise/Fall Time Select Register
Byte 18: Output Rise/Fall Time Select Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
1
0
CPUCLK_CS Slew Rate Control
1
0
CPUCLK0 Slew Rate Control
1
0
SDRAM0 Slew Rate Control
1
0
SDRAM (12:1) Slew Rate Control
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
1
0
PCICLK (6:1) Slew Rate Control
1
0
PCICLK0 Slew Rate Control
1
0
48MHz Slew Rate Control
1
0
24MHz Slew Rate Control
Notes:
1. PWD = Power on Default
2. The power on default for byte 13-20 depends on the harware (latch inputs FS[0:4]) or I²C (Byte 0 bit [1:7]) setting.
Be sure to read back and re-write the values of these 8 registers when VCO frequency change is desired for the first
pass.
0453C—10/26/04
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