ICS9250-14 Datasheet, PDF (3/13 Pages) Integrated Circuit Systems – Frequency Timing Generator for Pentium II Systems

ICS9250 - 14
Preliminary Product Preview
Frequency Selection
FS4 FS3 FS2
000
000
000
000
0
0
1
0
0
1
0
0
1
0
0
1
0
1
0
0
1
0
0
1
0
0
1
0
0
1
1
0
1
1
0
1
1
0
1
1
10 0
10 0
10 0
10 0
10
1
10
1
10
1
10
1
110
110
110
110
111
111
111
111
FS1 FS0
00
01
10
11
00
01
10
11
00
0
1
10
11
00
0
1
10
11
00
0
1
10
11
00
0
1
10
11
00
0
1
10
11
00
01
10
11
CPU
MHz
67.81
70.00
72.01
66.67
73.01
75.00
77.00
78.01
80.00
83.00
84.49
100.00
86.08
88.00
90.00
95.00
49.90
100.00
74.85
66.58
82.84
89.81
94.80
100.50
104.78
111.77
114.77
100.00
123.75
132.74
139.75
149.69
SDRAM
MHz
101.71
105.00
108.01
100.00
109.51
112.50
115.50
117.01
120.00
124.51
126.74
150.00
129.12
132.00
135.00
142.50
49.90
100.00
74.85
66.58
82.84
89.81
94.80
100.50
104.78
111.77
114.77
100.00
123.75
132.74
139.75
149.69
3V66 MHz
67.81
70.00
72.01
66.67
73.01
75.00
77.00
78.01
80.00
83.00
84.49
100.00
86.08
88.00
90.00
95.00
33.26
66.66
49.90
44.39
55.23
59.88
63.20
67.00
69.86
74.52
76.51
66.66
82.50
88.49
93.16
99.79
PCI
MHz
33.90
35.00
36.00
33.33
36.50
37.50
38.50
39.00
40.00
41.50
42.25
50.00
43.04
44.00
45.00
47.50
16.63
33.33
24.95
22.19
27.61
29.94
31.60
33.50
34.93
37.26
38.26
33.33
41.25
44.25
46.58
49.90
IOAPIC MHz
16.95
17.50
18.00
16.67
18.25
18.75
19.25
19.50
20.00
20.75
21.12
25.00
21.52
22.00
22.50
23.75
8.32
16.67
12.47
11.10
13.81
14.97
15.80
16.75
17.46
18.63
19.13
16.67
20.62
22.12
23.29
24.95
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