W83193R-02 Datasheet, PDF (7/18 Pages) Winbond – 83.3 MHZ 3-DIMM CLOCK

Preliminary W83193R-02/-04/-04A
8.3.1 Register 0: CPU Frequency Select Register (1 = Enable, 0 = Stopped)
BIT @POWERUP PIN
DESCRIPTION
7
0
- 0 = ±1.5% Spread Spectrum Modulation
1 = ±0.5% Spread Spectrum Modulation
6
0
-
SSEL2 (Frequency table selection by software via I²C)
5
0
-
SSEL1 (Frequency table selection by software via I²C)
4
0
-
SSEL0 (Frequency table selection by software via I²C)
3
0
- 0 = Selection by hardware
1 = Selection by software I²C - Bit 6:4
2
0
- 0 = Spread Spectrum center spread type
1 = Spread Spectrum down spread type
1
0
- 0 = Normal
1 = Spread Spectrum enabled
0
0
- 0 = Running
1 = Tristate all outputs
Frequency table selection by software via I²C
SSEL2 SSEL1 SSEL0 CPU, SDRAM (MHz)
0
0
0
50
0
0
1
75
0
1
0
83.3
0
1
1
68.5
1
0
0
83.3
1
0
1
75
1
1
0
60
1
1
1
66.8
PCI (MHz)
25
32
41.65
34.25
33.3
37.5
30
33.4
REF, IOAPIC (MHz)
14.318
14.318
14.318
14.318
14.318
14.318
14.318
14.318
FUNCTION TABLE
FUNCTION
DESCRIPTION
TRI-STATE
NORMAL
CPU
Hi-Z
See table
PCI
Hi-Z
See table
OUTPUTS
SDRAM
Hi-Z
CPU
REF
Hi-Z
14.318
IOAPIC
Hi-Z
14.318
Publication Release Date: April 1999
-7-
Revision A1