W48S87-04 Datasheet, PDF (10/21 Pages) Cypress Semiconductor – Spread Spectrum 3 DIMM Desktop Clock

PRELIMINARY
W48S87-04
Table 5. Additional Frequency Selections through Serial Data Interface Data Bytes
Input Conditions
Output Frequency
Data Byte 0, Bit 3 = 1
Bit 6
BYT0_SEL2
Bit 5
BYT0_SEL1
Bit 4
BYT0_SEL0
CPU, SDRAM Clocks
(MHz)
PCI Clocks
(MHz)
0
0
0
50
25
0
0
1
75.0
32
0
1
0
83.3
41.65
0
1
1
68.5
34.25
1
0
0
55.0
27.5
1
0
1
75.0
37.5
1
1
0
60.0
30.0
1
1
1
66.8
33.4
Table 6. Select Function for Data Byte 0, Bits 0:1
Input Conditions
Function
Data Byte 0
Bit 1
Bit 0
CPU0:3,
SRAM0:11
Normal Operation
0
0
Note 3
Test Mode
0
1
X1/2
Spread Spectrum
1
0
Note 3
SS±0.5%
Three-state
1
1
Hi-Z
Note:
3. CPU, SDRAM, and PCI frequency selections are listed in Table 1 and Table 5.
4. In Test Mode, the 48/24MHz clock outputs are:
- X1/2 for 48-MHz output.
- X1/4 for 24-MHz output.
Output Conditions
PCI_F,
PCI0:5
Note 3
X1/4
Note 3
SS±0.5%
Hi-Z
REF0:1, IOAPIC
14.318 MHz
X1
14.318 MHz
Hi-Z
48/24MHZ
48/24 MHz
Note 4
48/24 MHz
Hi-Z
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