ICS9248-77 Datasheet, PDF (3/14 Pages) Integrated Circuit Systems – Frequency Timing Generator for PENTIUM II Systems

ICS9248-77
Frequency Selection
FS3
FS2
FS1
FS0
CPU
MHz
CPU/2
MHz
PCI
MHz
0 0 0 0 105 52.5 35
0 0 0 1 75 37.5 37.5
0 0 1 0 100.3 50.15 33.4
0 0 1 1 66.8 33.4 33.4
0 1 0 0 110 55 36.6
0 1 0 1 115 57.5 38.3
0 1 1 0 117 58.5 39
0 1 1 1 120 60
40
1 0 0 0 125 62.5 41.6
1 0 0 1 127 63.5 42.3
1 0 1 0 133.3 66.5 33.3
1 0 1 1 135 67.5 33.75
1 1 0 0 137 68.5 34.25
1 1 0 1 140 70
35
1 1 1 0 145 72.5 36.25
1 1 1 1 150 75 37.5
3V66 MHz
IOAPIC MHz
SEL_3V66=0
70
64*
66.6
66.6
64*
64*
64*
64*
64*
64*
66.6
67.5
68.5
70
64*
64*
SEL_3V66=1
70
75
66.6
66.6
73.3
76.6
78
80
83.3
84.6
66.6
67.5
68.5
70
72.5
75
FREQ_APIC=0 FREQ_APCI=1
17.5
35
18.75
37.5
16.7
33.4
16.67
33.4
18.3
36.6
19.16
38.3
19.5
39
20
40
20.8
41.6
21.16
42.3
16.6
33.3
16.8
33.75
17.125
34.25
17.5
35
18.125
36.25
18.75
37.5
Note:
* These output frequencies are Not synchronous to CPUCLK and Do Not have Spread Spectrum modulation.
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