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ICS9248-199 Datasheet, PDF (1/21 Pages) Integrated Circuit Systems – Frequency Generator for SIS 735/740 with AMD K7 Processor
Integrated
Circuit
Systems, Inc.
ICS9248-199
Frequency Generator for SIS 735/740 with AMD K7 Processor
Recommended Application:
Main system clock for SIS 735/740 with
AMD K7 chipset.
Output Features:
• 1 - CPU @ 2.5V
• 1 - Differential pair open drain CPU clock
• 1 - IOAPIC @ 2.5V
• 1 - SDRAM @ 3.3V
• 6- PCI @3.3V
• 2 - AGP @ 3.3V
• 1- 48MHz, @3.3V fixed
• 1- 24/48MHz, @3.3V selectable by I2C
(Default is 24MHz)
• 2- REF @3.3V, 14.318MHz
Frequency Table
Bit 2
FS4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Bit 7
FS3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Bit 6
FS2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Bit 5
FS1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Bit 4
FS0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
CPU
66.66
100.00
166.66
133.33
66.66
100.00
100.00
133.33
112.00
124.00
138.00
150.00
100.00
133.33
150.00
160.00
90.00
100.90
103.00
133.90
137.33
137.33
100.90
133.90
107.00
107.00
142.66
110.00
110.00
146.66
166.70
200.00
SDRAM
66.66
100.00
166.66
133.33
100.00
66.66
133.33
100.00
112.00
124.00
138.00
150.00
166.66
166.66
100.00
120.00
90.00
100.90
103.00
133.90
103.00
137.33
133.90
100.90
107.00
142.66
142.66
110.00
146.66
146.66
125.00
200.00
PCI
33.33
33.33
33.33
33.33
33.33
33.33
33.33
33.33
33.60
31.00
34.50
30.00
31.25
33.33
30.00
30.00
30.00
33.63
34.33
33.48
34.33
34.33
33.48
33.48
35.66
35.66
35.66
36.66
36.66
36.66
31.25
33.33
AGP
SEL = 0
66.66
66.66
66.66
66.66
66.66
66.66
66.66
66.66
67.20
62.00
69.00
60.00
62.50
66.66
60.00
60.00
60.00
67.27
68.67
68.67
66.95
68.67
66.95
66.95
71.33
71.33
71.33
73.33
73.33
73.33
66.68
66.66
AGP
SEL = 1
50.00
50.00
55.60
50.00
50.00
50.00
50.00
50.00
56.00
46.50
46.00
50.00
50.00
55.30
50.00
48.00
45.00
50.45
51.50
51.56
51.45
50.21
50.21
50.21
53.50
53.50
53.50
55.00
55.00
55.00
55.57
50.00
Note: Please see full table on page 4.
Features:
• Programmable output frequency.
• Programmable output divider ratios.
• Programmable output rise/fall time.
• Programmable output skew.
• Programmable spread percentage for EMI control.
• Watchdog timer technology to reset system
if system malfunctions.
• Programmable watch dog safe frequency.
• Support I2C Index read/write and block read/write
operations.
• Uses external 14.318MHz crystal.
Skew Specifications:
• CPU - CPU: < 175ps
• PCI - PCI: < 500ps
• CPU - SDRAM: < 250ps
• AGP - AGP: <175ps
• CPU - AGP, PCI: 1-4ns
Pin Configuration
VDDREF
1
2*FS0/REF0
2
2*FS1/REF1
3
GND
4
GND
5
X1
6
X2
7
GND
8
2FS2/PCICLK_F
9
2FS3/PCICLK0
10
VDDPCI
11
2**FS4/PCICLK1
12
**PCICLK2
13
GND
14
**PCICLK3
15
**PCICLK4
16
VDDAGP
17
AGPCLK0
18
AGPCLK1
19
GND
20
VDD48
21
48MHz
22
2AGPSEL/124_48MHz
23
GND
24
48
VDDLAPIC
47
IOAPIC*
46
GND
45
VDDL
44
CPUCLKT0
43
CPUCLKC0
42
GND
41
VDDL
40
CPUCLK
39
GND
38
NC
37
NC
36
VDDSDR
35
SDRAM
34
GND
33
PCI_STOP#2
32
CPU_STOP#2
31
PD#1
30
SDRAM_STOP#2
29
AGP_STOP#2
28
SDATA
27
SCLK
26
GND
25
VDD
48-Pin 300mil SSOP
* These are double strength.
** (1X/2X) have single or double strength to
drive 2 loads.
1. Internal pull-up, of 120K to VDD.
2. These inputs have a 120K pull down to GND.
0376E—12/23/02
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