W48S87-72
| Model | W48S87-72 |
| Description | Desktop/Notebook Frequency Generator |
| PDF file | Total 19 pages (File size: 248K) |
| Chip Manufacturer | CYPRESS |
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
0
1
CPU, SDRAM
Clocks (MHz)
60
66.8
PCI Clocks
(MHz)
30
33.4
Block Diagram
VDDQ3
REF0
X1
X2
XTAL
OSC
PLL Ref Freq
VDDQ2
IOAPIC
VDDQ2
CPU0
CPU_STOP#
I/O
Control
Stop
Output
Control
CPU1
CPU2
CPU3
VDDQ3
SDRAM0
SDRAM1
SDRAM2
60/66_SEL
PLL 1
SDRAM3
SDRAM4
SDRAM5
÷2
SDRAM6
SDRAM7
PCI_F
Stop
Output
Control
Power
Down
Control
PCI0
PCI1
PCI2
PWR_DWN#
PCI3
PCI4
PCI5
PLL2
48/24MHZ
48/24MHZ
REF1
Pin Configuration
REF1
REF0
GND
X1
X2
MODE
VDDQ3
PCI_F
PCI0
GND
PCI1
PCI2
PCI3
PCI4
VDDQ3
PCI5
GND
60/66_SEL
SDATA
SCLOCK
VDDQ3
48/24MHZ
48/24MHZ
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
VDDQ3
CPU2.5#
VDDQ2
IOAPIC
PWR_DWN#
GND
CPU0
CPU1
VDDQ2
CPU2
CPU3
GND
SDRAM0
SDRAM1
VDDQ3
SDRAM2
SDRAM3
GND
SDRAM4
SDRAM5
VDDQ3
SDRAM6/CPU_STOP#
SDRAM7/PCI_STOP#
VDDQ3
W48S87-72
MODE
Note:
1. Additional frequency selections provided by serial data interface; refer to
Table 5
on page 8.
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134 •
408-943-2600
August 4, 2000 rev. *A
