Integrated
Circuit
Systems, Inc.
ICS951411
0891E—03/07/05
Pin Configuration
Recommended Application:
ATI RS400 systems using Intel P4
TM
processors
Output Features:
6 - Pairs of SRC/PCI-Express clocks
2 - Pairs of ATIG (SRC/PCI Express*) clocks
3 - Pairs of Intel P4 clocks
3 - 14.318 MHz REF clocks
1 - 48MHz USB clock
1 - 33 MHz PCI clock seed
Key Specifications:
CPU outputs cycle-cycle jitter < 85ps
SRC output cycle-cycle jitter <125ps
PCI outputs cycle-cycle jitter < 250ps
+/- 300ppm frequency accuracy on CPU & SRC clocks
System Clock Chip for ATI RS400 P4
TM
-based Systems
Features/Benefits:
2- Programmable Clock Request pins for SRC clocks
Supports CK410 or CK409 frequency table mapping
Spread Spectrum for EMI reduction
Outputs may be disabled via SMBus
External crystal load capacitors for maximum
frequency accuracy
56-pin SSOP & TSSOP
*Other names and brands may be claimed as the property of others.
Functionality - (CK410# = 0)
FS_C
1
FS_B
1
FS_A
1
CPU
MHz
266.66 100.00 33.33
133.33 100.00 33.33
200.00 100.00 33.33
166.66 100.00 33.33
333.33 100.00 33.33
100.00 100.00 33.33
400.00 100.00 33.33
RESERVED
SRC
MHz
PCI
MHz
REF
MHz
14.318 48.000
14.318 48.000
14.318 48.000
14.318 48.000
14.318 48.000
14.318 48.000
14.318 48.000
14.318 48.000
U
SB
MHz
0
1
0
1
0
1
0
1
Functionality - (CK410# = 1)
FS_C
1
Byte6
bit5
FS_B
1
FS_A
1
CPU
MHz
SRC
MHz
PCI
MHz
REF
MHz
U
SB
MHz
0
1
0
1
0
1
0
1
0
0
1
1
0
0
1
1
100.00 100.00 33.33
200.00 100.00 33.33
133.33 100.00 33.33
166.67 100.00 33.33
200.00 100.00 33.33
400.00 100.00 33.33
266.67 100.00 33.33
333.33 100.00 33.33
14.318 48.000
14.318 48.000
14.318 48.000
14.318 48.000
14.318 48.000
14.318 48.000
14.318 48.000
14.318 48.000
1. FS_C, FS_B and FS_A are low-threshold inputs. Please see the V
IL_FS
and V
IH_FS
specifications in the Input/Supply/Common Output Parameters Table for correct values.
1
0
0
0
1
1
0
1
X1 1
X2 2
56 VDDREF
55 GND
54 **FS_A/REF0
53 **FS_B/REF1
52 **TEST_SEL/REF2
51 VDDPCI
50 **CK410#/PCICLK0
49 GNDPCI
48 *CPU_STOP#
47 CPUCLKT0
46 CPUCLKC0
45 VDDCPU
44 GNDCPU
43 CPUCLKT1
42 CPUCLKC1
41 CPUCLKT2_ITP
40 CPUCLKC2_ITP
39 VDDA
38 GNDA
37 IREF
36 GNDSRC
35 VDDSRC
34 SRCCLKT0
33 SRCCLKC0
32 VDDATI
31 GNDATI
30 ATIGCLKT0
29 ATIGCLKC0
VDD48 3
USB_48MHz 4
GND 5
VTT_PWRGD#/PD 6
SCLK 7
SDATA 8
**FS_C 9
**CLKREQA# 10
**CLKREQB# 11
SRCCLKT7 12
SRCCLKC7 13
VDDSRC 14
GNDSRC 15
SRCCLKT6 16
SRCCLKC6 17
SRCCLKT5 18
SRCCLKC5 19
GNDSRC 20
VDDSRC 21
SRCCLKT4 22
SRCCLKC4 23
SRCCLKT3 24
SRCCLKC3 25
GNDSRC 26
ATIGCLKT1 27
ATIGCLKC1 28
Note:
Pins preceeded by '**' have a 120 Kohm Internal Pull Down resistor
Pins preceeded by '*' have a 120 Kohm Internal Pull Up resistor
I