ICS9248-78 Datasheet, PDF (3/13 Pages) Integrated Circuit Systems – Frequency Timing Generator for Pentium II Systems

ICS9248 - 78
Preliminary Product Preview
Frequency Selection
FS3
FS2
FS1
FS0
CPU SDRAM PCI
MHz MHz MHz
0 0 0 0 100.23 100.23 33.41
0 0 0 1 100.90 100.90 33.63
0 0 1 0 105.00 105.00 35.00
0 0 1 1 66.89 100.33 33.44
0 1 0 0 120.00 120.00 40.00
0 1 0 1 124.00 124.00 41.33
0 1 1 0 133.30 133.30 44.43
0 1 1 1 133.30 133.30 33.32
1 0 0 0 140.00 140.00 35.00
1 0 0 1 150.00 150.00 37.50
1 0 1 0 114.99 114.99 38.33
1 0 1 1 70.00 105.00 35.00
1 1 0 0 75.00 112.50 37.50
1 1 0 1 83.31 124.96 41.65
1 1 1 0 90.00 90.00 30.00
1 1 1 1 95.00 95.00 31.67
3V66 MHz
SEL_3V66=0
66.82
67.26
70.00
66.89
64.00*
64.00*
64.00*
66.65
70.00
64.00*
64.00*
70.00
64.00*
64.00*
60.00
63.33
SEL_3V66=1
66.82
67.26
70.00
66.89
80.00
82.66
88.86
66.65
70.00
75.00
76.66
70.00
75.00
83.31
60.00
63.33
IOAPIC MHz
16.70
16.81
17.50
16.72
20.00
20.67
22.21
16.66
17.50
18.75
19.16
17.50
18.75
20.83
15.00
15.83
Note:
* These output frequencies are not synchronous to CPUCLK and do not have spread spectrum modulation.
Clock Enable Configuration
PD#
CPUCLK SDRAM IOAPIC
66MHz
PCICLK
REF,
48MHz
Osc
0
LOW
LOW
LOW
LOW
LOW
LOW
OFF
1
ON
ON
ON
ON
ON
ON
ON
VCOs
OFF
ON
3