ICS94211 Datasheet, PDF (8/16 Pages) Integrated Circuit Systems – Programmable System Frequency Generator for PII/III™

ICS94211
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
PCICLK_F Skew Control
PCICLK [0:4} Skew Control
SDRAM_F Skew Control
SDRAM [0:7} Skew Control
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
SDRAM [8:11] Skew Control
X Reserved
X Reserved
X Reserved
X Reserved
X Reserved
X Reserved
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
CPUCLK_F: Slew Rate Control
CPUCLK1: Slew Rate Control
SDRAM_F: Slew Rate Control
SDRAM [0:11] Slew Rate Control
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
PCI {0:4]: Slew Rate Control
PCI_F Slew Rate Control
48MHz: Slew Rate Control
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.
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