W196 Datasheet, PDF (7/11 Pages) Cypress Semiconductor – Spread Spectrum FTG for 440BX and VIA Apollo Pro-133

W196
Table 5. Additional Frequency Selections through Serial Data Interface Data Bytes
Input Conditions
Data Byte 3, Bit [7:4, 1:0]
Output Frequency
Bit [1:0]
Bit 7
SEL_3
Bit 6
SEL_2
Bit 5
SEL_1
Bit 4
SEL_0
CPU, SDRAM
Clocks (MHz)
PCI Clocks
(MHz)
00
0
0
0
0
78
39
00
0
0
0
1
81
40.5
00
0
0
1
0
113.5
37.8
00
0
0
1
1
66.8
33.4
00
0
1
0
0
117
39
00
0
1
0
1
118.5
39.5
00
0
1
1
0
122
37.3
00
0
1
1
1
100
33.3
00
1
0
0
0
126
31.5
00
1
0
0
1
135
33.75
00
1
0
1
0
137
34.25
00
1
0
1
1
138.5
34.62
00
1
1
0
0
142
35.5
00
1
1
0
1
144
36
00
1
1
1
0
155
38.75
00
1
1
1
1
133.3
33.3
10
0
0
0
0
124
41.3
10
0
0
0
1
75
37.5
10
0
0
1
0
83.3
41.65
10
0
0
1
1
66.8
33.4
10
0
1
0
0
90
30
10
0
1
0
1
112
37.3
10
0
1
1
0
95
31.67
10
0
1
1
1
100
33.3
10
1
0
0
0
120
40
10
1
0
0
1
115
38.3
10
1
0
1
0
110
36.67
10
1
0
1
1
105
35
10
1
1
0
0
140
35
10
1
1
0
1
150
37.5
10
1
1
1
0
124
31
10
1
1
1
1
133.3
33.3
If Spread Is On
Spread Percentage
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
±0.5% Center
Table 6. Select Function for Data Byte 3, Bits 0:1
Input Conditions
Data Byte 3
Function
Bit 1
Bit 0
Spread Spectrum OFF
0
0
Test Mode
0
1
Spread Spectrum ON (default)
1
0
Three-state
1
1
Note:
2. CPU and PCI frequency selections are listed in Table 1 and Table 5.
CPU0:1
Note 2
X1/2
±0.5%
Hi-Z
Output Conditions
PCI_F, PCI1:6
Note 2
CPU/2, 3, or 4
±0.5%
Hi-Z
REF2X,
IOAPIC
14.318 MHz
X1
14.318 MHz
Hi-Z
48MHZ
48 MHz
X1/2
48 MHz
Hi-Z
24MHZ
24 MHz
X1/4
24 MHz
Hi-Z
Rev 1.0, November 28, 2006
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