ICS9148-37 Datasheet, PDF (5/16 Pages) Integrated Circuit Systems – Frequency Generator & Integrated Buffers for PENTIUM/Pro

ICS9148 - 37
Serial Configuration Command Bitmap
Byte0: Functionality and Frequency Select Register
(default = 0)
Bit
Description
Bit 7
0 - ±0.25% Spread Spectrum Modulation
1 - ±0.6% Spread Spectrum Modulation
Bit6 Bit5 CPU Clock PCI AGP
Bit4
111
100
33.3 66.6
110
95.25 31.75 63.5
Bit
101
83.3
33.3 66.6
6:4
100
75
30
60
011
75
37.5
75
010
68.5
34.25 68.5
001
66.8
33.4 66.8
000
60
30
60
0 - Frequency is selected by hardware
Bit 3
select,
Latched Inputs
1 - Frequency is selected by Bit 6:4 (above)
0 - Spread Spectrum center spread type.
1 - Spread Spectrum down spread type.
Bit 1
0 - Normal
1 - Spread Spectrum Enabled
Bit 0
0 - Running
1- Tristate all outputs
PWD
0
Note
1
0
0
0
0
Byte 1: CPU, Active/Inactive
Register (1 = enable, 0 = disable)
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Pin #
-
-
-
-
40
41
43
44
PWD
1
1
1
1
1
1
1
1
Description
(Reserved)
(Reserved)
(Reserved)
(Reserved)
CPUCLK3 (Act/Inact)
CPUCLK2 (Act/Inact)
CPUCLK1 (Act/Inact)
CPUCLK0 (Act/Inact)
Notes:
1. Inactive means outputs are held LOW and are disabled
from switching.
Byte 2: PCI Active/Inactive
Register (1 = enable, 0 = disable)
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Pin #
-
7
15
13
12
11
10
8
PWD
1
1
1
1
1
1
1
1
Description
(Reserved)
PCICLK_F (Act/Inact)
AGP0 (Act/Inact)
PCICLK4 (Act/Inact)
PCICLK3 (Act/Inact)
PCICLK2 (Act/Inact)
PCICLK1 (Act/Inact)
PCICLK0(Act/Inact)
Notes:
1. Inactive means outputs are held LOW and are disabled
from switching.
0143G—08/04/04
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