W149 Datasheet, PDF (8/15 Pages) Cypress Semiconductor – 440BX AGPset Spread Spectrum Frequency Synthesizer

W149
Table 6. Additional Frequency Selections through Serial Data Interface Data Bytes^[3]
Input Conditions
Output Frequency
Data Byte 0, Bit 3 = 1
Bit 6
SEL_2
Bit 5
SEL_1
Bit 4
SEL_0
CPU0:1,
SDRAM0:12 (MHz)
PCI_F, 1:5
(MHz)
1
1
1
100. 2
33.4
1
1
0
(Reserved)
(Reserved)
1
0
1
100
33.3
1
0
0
103
34.3
0
1
1
66.8
33.4
0
1
0
83.3
41.65
0
0
1
66.8
33.4
0
0
0
124
41.3
Spread%
–0.5
(Reserved)
±0.5
–0.5
–0.5
–0.5
±0.5
–0.5
Table 7. Select Function for Data Byte 0, Bits 0:1
Input Conditions
Data Byte 0
Function
Bit 1
Bit 0
CPU0:1
Normal Operation
X
0
Note 1
Three-state
1
1
Hi-Z
Note:
3. CPU and PCI frequency selections are listed in Table 2 and Table 6.
Output Conditions
PCI_F,
PCI1:5
Note 1
Hi-Z
REF0:1,
IOAPIC
14.318 MHz
Hi-Z
48 MHZ
48 MHz
Hi-Z
24 MHZ
24 MHz
Hi-Z
Rev 1.0, November 21, 2006
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