CY28381 Datasheet, PDF (1/19 Pages) Cypress Semiconductor – High-Performance SiS645DX/648DX/650/651 Intel Pentium 4 Clock Synthesizer

CY28381
High-Performance SiS645DX/648DX/650/651
Intel Pentium^ 4 Clock Synthesizer
Features
• Supports Pentium^® 4-type CPUs
• 3.3V power supply
• Eight copies of PCI clocks
• One 48-MHz USB clock
• Two copies of ZCLK cocks
• One 48-MHz/24-MHz Programmable SIO clock
• Two differential CPU clock pairs
• SMBus support with readback capabilities
• Spread Spectrum electromagnetic interference (EMI)
reduction
• Dial-A-Frequency^® features
• Dial-A-Ratio™ features
• Dial-A-dB™ features
• 48-pin SSOP Package
• Watchdog function
Block Diagram
XIN
XOUT
PLL1
CPU_STP#
IREF
FS[0:4]
MULT0
Power
on
Latch
VTT_PWRGD
/2
PCI_STP#
PLL2
PD#
SDATA
SCLK
WD
Logic
I2C
Logic
Pin Configuration^[1]
REF(0:2)
CPUT[0:1]
CPUC[0:1]
SDCLK
AGP[0:1]
ZCLK[0:1]
PCI[0:5]
PCIF[0:1]
48M
48M_24M#
SRESET#
VDDR 1
48
**FS0/REF0 2
47
**FS1/REF1 3
46
**FS2/REF2 4
45
VSSR 5
44
XIN 6
43
XOUT 7
42
VSSZ 8
41
ZCLK0 9
40
ZCLK1 10
39
VDDZ 11
38
*SRESET#/PCI_STP# 12
37
VDDP 13
36
**FS3/PCIF0 ¹⁴
35
**FS4/PCIF1 15
34
PCI0 16
33
PCI1 17
32
VSSP 18
31
VDDP 19
30
PCI2 20
29
PCI3 21
28
PCI4 22
27
PCI5 ₂₃
26
VSSP 24
25
48 pin SSOP
VDDSD
SDCLK
VSSSD
CPU_STP#*
CPUT1
CPUC1
VDDC
VSSC
CPUT0
CPUC0
IREF
VSSA
VDDA
SCLK
SDATA
PD#/VTT_PWRGD*
VSSAGP
AGP0
AGP1
VDDAGP
VDD48M
48M
24_48M/MULT0*
VSS48M
Note:
1. Pins marked with [*] have internal 150K pull-up resistors. Pins marked with [**] have internal 150K pull-down resistors.
Cypress Semiconductor Corporation • 3901 North First Street • San Jose, CA 95134 • 408-943-2600
Document #: 38-07546 Rev. **
Revised May 20, 2003