W48S87-72 Datasheet, PDF (1/19 Pages) Cypress Semiconductor – Desktop/Notebook Frequency Generator

W48S87-72
Desktop/Notebook Frequency Generator
Features
• Maximized EMI suppression using Cypress’s Spread
Spectrum technology
• ±0.5% Spread Spectrum clocking
• Equivalent to the W48S67-72 with Spread Spectrum for
Tilamook, MMO, and Deschutes processors
• Generates system clocks for CPU, IOAPIC, SDRAM,
PCI, USB plus 14.318-MHz (REF0:1)
• Serial data interface (SDATA, SCLOCK inputs) provides
additional CPU/PCI clock frequency selections, individ-
ual output clock disabling and other functions
• MODE input pin selects optional power management
input control pins (reconfigures pins 26 and 27)
• Two fixed outputs separately selectable as 24-MHz or
48-MHz (default = 48-MHz)
• V_DDQ3 = 3.3V±5%, V_DDQ2 = 2.5V±5%
• Uses external 14.318-MHz crystal
• Available in 48-pin SSOP (300 mils)
• 10Ω CPU output impedance
Table 1. Pin Selectable Frequency^[1]
60/66_SEL
CPU, SDRAM
Clocks (MHz)
PCI Clocks
(MHz)
0
60
30
1
66.8
33.4
Block Diagram
Pin Configuration
X1
XTAL
X2
OSC
PLL Ref Freq
CPU_STOP#
MODE
I/O
Control
Stop
Output
Control
60/66_SEL
PLL 1
÷2
VDDQ3
REF0
REF1
VDDQ2
IOAPIC
VDDQ2
CPU0
CPU1
CPU2
CPU3
VDDQ3
SDRAM0
SDRAM1
SDRAM2
SDRAM3
SDRAM4
SDRAM5
SDRAM6
SDRAM7
REF1 1
REF0 2
GND 3
X1 4
X2 5
MODE 6
VDDQ3 7
PCI_F 8
PCI0 9
GND 10
PCI1 11
PCI2 12
PCI3 13
PCI4 14
VDDQ3 15
PCI5 16
GND 17
60/66_SEL 18
SDATA 19
SCLOCK 20
VDDQ3 21
48/24MHZ 22
48/24MHZ 23
GND 24
PWR_DWN#
Stop
Output
Control
Power
Down
Control
PCI_F
PCI0
PCI1
PCI2
PCI3
PCI4
PCI5
PLL2
48/24MHZ
48/24MHZ
Note:
1. Additional frequency selections provided by serial data interface; refer to Table 5 on page 8.
48 VDDQ3
47 CPU2.5#
46 VDDQ2
45 IOAPIC
44 PWR_DWN#
43 GND
42 CPU0
41 CPU1
40 VDDQ2
39 CPU2
38 CPU3
37 GND
36 SDRAM0
35 SDRAM1
34 VDDQ3
33 SDRAM2
32 SDRAM3
31 GND
30 SDRAM4
29 SDRAM5
28 VDDQ3
27 SDRAM6/CPU_STOP#
26 SDRAM7/PCI_STOP#
25 VDDQ3
Cypress Semiconductor Corporation • 3901 North First Street • San Jose • CA 95134 • 408-943-2600
August 4, 2000 rev. *A