ICS9248-199
Integrated
Circuit
Systems,Inc.
Frequency Generator for SIS 735/740 with AMD K7 Processor
Features:
Recommended Application:
Main system clock for SIS 735/740 with
AMD K7 chipset.
•
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.
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
•
•
Programmable watch dog safe frequency.
Support I2C Index read/write and block read/write
operations.
2 - AGP @ 3.3V
•
Uses external 14.318MHz crystal.
1- 48MHz, @3.3V fixed
1- 24/48MHz, @3.3V selectable by I2C
(Default is 24MHz)
Skew Specifications:
•
•
•
•
•
CPU - CPU: < 175ps
PCI - PCI: < 500ps
•
2- REF @3.3V, 14.318MHz
CPU - SDRAM: < 250ps
AGP - AGP: <175ps
CPU - AGP, PCI: 1-4ns
Frequency Table
Pin Configuration
Bit 2 Bit 7 Bit 6 Bit 5 Bit 4
FS4 FS3 FS2 FS1 FS0
AGP
AGP
VDDREF
*FS0/REF0
*FS1/REF1
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
VDDLAPIC
IOAPIC*
GND
CPU SDRAM PCI
66.66 66.66 33.33
100.00 100.00 33.33
166.66 166.66 33.33
133.33 133.33 33.33
SEL = 0 SEL = 1
2
2
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
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
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
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
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
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
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
VDDL
GND
X1
X2
GND
CPUCLKT0
CPUCLKC0
GND
VDDL
CPUCLK
GND
NC
NC
VDDSDR
SDRAM
GND
66.66
100.00 66.66
100.00 33.33
33.33
2
100.00 133.33 33.33
133.33 100.00 33.33
112.00 112.00 33.60
124.00 124.00 31.00
138.00 138.00 34.50
150.00 150.00 30.00
100.00 166.66 31.25
133.33 166.66 33.33
150.00 100.00 30.00
160.00 120.00 30.00
FS2/PCICLK_F
2
FS3/PCICLK0
VDDPCI
2
**FS4/PCICLK1
**PCICLK2
GND
**PCICLK3
**PCICLK4
VDDAGP
AGPCLK0
AGPCLK1
GND
2
2
PCI_STOP#
CPU_STOP#
1
PD#
2
SDRAM_STOP#
2
90.00
90.00 30.00
AGP_STOP#
100.90 100.90 33.63
103.00 103.00 34.33
133.90 133.90 33.48
137.33 103.00 34.33
137.33 137.33 34.33
100.90 133.90 33.48
133.90 100.90 33.48
107.00 107.00 35.66
107.00 142.66 35.66
142.66 142.66 35.66
110.00 110.00 36.66
110.00 146.66 36.66
146.66 146.66 36.66
166.70 125.00 31.25
200.00 200.00 33.33
VDD48
SDATA
SCLK
GND
48MHz
AGPSEL/ 24_48MHz
GND
2
1
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.
Note: Please see full table on page 4.
0376E—12/23/02