W167B Datasheet, PDF (2/18 Pages) Cypress Semiconductor – 133-MHz Spread Spectrum FTG for Pentium II Platforms

PRELIMINARY
W167B
Pin Definitions
Pin Name
CPU0:2
Pin
No.
35, 36, 39
SEL133/100#
25
PCI0/SEL2
7
PCI1/SEL1
8
PCI2:9
3V66_0:2
CPUdiv2
10, 11, 12,
13, 15, 16,
18, 19
21, 22, 23
42
IOAPIC0:2
48MHZ/SEL0
46, 45, 1
27
SIO/24_48#MHz
28
REF2X
PWRDWN#
X1
X2
SDATA
SCLK
VDDQ2
VDDQ3
GND
2
31
4
5
34
30
37, 40, 43, 47
3, 9, 17, 24,
29, 33
6, 14, 20, 26,
32, 38, 41,
44, 48
Pin
Type
O
I
I/O
I/O
O
O
O
O
I/O
I/O
O
I
I
I
I/O
I
P
P
G
Pin Description
CPU Clock Outputs 0 through 2: CPU clock outputs. Their output voltage
swing is controlled by voltage applied to VDDQ2.
SEL133/100#: Frequency selection input pin as shown in Table 1.
PCI Clock Output 0 and Selection Bit 2: As an output, this pin works in
conjunction with PCI2:9. When an input, this pin functions as part of the fre-
quency selection address (see Table 1).
PCI Clock Output 1 and Selection Bit 1: As an output, this pin works in
conjunction with PCI2:9. When an input, this pin functions as part of the fre-
quency selection address (see Table 1).
PCI Clock Outputs 2 through 9: Output voltage swing is controlled by voltage
applied to VDDQ3.
66-MHz Clock Outputs 0 through 2: Output voltage swing is controlled by
voltage applied to VDDQ3.
CPU-Divide-By-2 Output: This serves as a reference input signal for Direct
Rambus Clock Generator (Cypress W134). The output voltage is determined
by VDDQ2.
I/O APIC Clock Output 0 through 2: Provide outputs synchronous to CPU
clock. See Table 1 and Table 5 for their relation to other system clock outputs.
48-MHz Output and Selection Bit 0: Fixed clock output that defaults to
48-MHz following device power-up. When an input, this pin functions as part of
the frequency selection address (see Table 1).
Super I/O Reference Clock Output and SIO Clock Frequency Select: Fixed
clock output that provides the reference input clock to a Super I/O device. The
output frequency is determined by the input value on this pin during power up.
If input is sampled HIGH, the output operates at 24 MHz, otherwise, the output
operates at 48 MHz.
Fixed 14.318-MHz Output: With double strength driving capability.
Power Down Control
Crystal Connection or External Reference Frequency Input: This pin has
dual functions. It can be used as an external 14.318-MHz crystal connection or
as an external reference frequency input.
Crystal Connection: An input connection for an external 14.318-MHz crystal.
If using an external reference, this pin must be left unconnected.
Serial Data Input: Data input for Serial Data Interface. Refer to Serial Data
Interface section that follows.
Serial Clock Input: Clock input for Serial Data Interface. Refer to Serial Data
Interface section that follows.
Power Connection: Connected to 2.5V power supply.
Power Connection: Connected to 3.3V supply.
Ground Connection: Connect all ground pins to the common system ground
plane.
2