HD151TS207SS Datasheet, PDF (18/38 Pages) Renesas Technology Corp – Mother Board Clock Generator for Intel P4+ Chipset (Springdale)

HD151TS207SS
I²C Controlled Register Bit Map (cont.)
Byte18 Control Register
Bit Description
Contents
Type Default
7
VCO2 Frequency Control Bit7
These bits are 10MHz digit of
R/W 0
6
VCO2 Frequency Control Bit6
VCO2 frequency.
R/W 0
0000 = 0, 0001 = 1 …. 1001 = 9
5
VCO2 Frequency Control Bit5
R/W 0
4
VCO2 Frequency Control Bit4
R/W 0
3
VCO2 Frequency Control Bit3
These bits are 1MHz digit of
R/W 0
2
VCO2 Frequency Control Bit2
VCO2 frequency.
R/W 0
0000 = 0, 0001 = 1 …. 1001 = 9
1
VCO2 Frequency Control Bit1
R/W 0
0
VCO2 Frequency Control Bit0
R/W 0
Note: 1. B17[3:0] and B18[7:0] must be written together (at writing B18) in every case.
Note
See
Note
1
How to set VCO2 frequency to 666 MHz.
Write
Byte17
0 0 0 10 1 1 0
ON
6
Byte18
0 1 1 00 1 1 0
6
6
max 720
min 200
How to read actual frequency of VCO2 and CPU clock
Byte17[4] = 1
Actual VCO2 freq. read back.
Byte19
0 1 1 00 1 1 0
Byte20
0 1 1 01 0 0 0
6
6
6
8
Note:
Case of VCO2 = 666.8 MHz.
Other clock frequency are able to read using the same way as shown at upper.
Byte19, Byte20 = Read back of VCO2 actual frequency.
Byte21, Byte22 = Read back of CPU actual frequency.
Rev.1.00, Apr.25.2003, page 18 of 38