Philips Semiconductors

Product specification

PCK2020

CK00 (100/133MHz) spread spectrum

differential system clock generator

2000 Nov 13

3

PIN DESCRIPTION

PIN NUMBER

SYMBOL

FUNCTION

1

2, 3

Ref0/MultSel0

Ref1/MultSel1

During power up, pins functions as a latched inputs that enables MULTSEL0 and

MULTSEL1 prior to the pins being used for output of 3 V at 14.318 MHz. Part must be

clocked to latch data in.

4

5

XTAL_IN

Crystal input

6

XTAL_OUT

Crystal output

7, 13, 19

8, 9, 11, 12, 14, 15, 17,

18, 20, 21

PCICLK[0–9]

3.3 V PCI clock outputs fixed at 33 MHz.

10, 16, 22

23

SEL100/133

Select input pin for enabling 133 MHz or 100 MHz CPU outputs.

24

25, 26

48 MHz/SelA

48 MHz/SelB

3.3 V fixed 48 MHz clock outputs. During power up, pins functions as latched inputs

that enables SELA and SELB prior to the pins being used for output of 3 V at 48 MHz.

Part must be clocked to latch data in.

27

28

PWRDWN

Device enters power down mode when held low. Asserts low.

29, 36

30, 31, 34, 35

3V66[0–3]

3.3 V fixed 66 MHz CPU clock outputs.

32, 33

37

38

3.3 V power supply for analog circuits.

39

I_REF

This pin controls the reference current for the host pairs. This pin requires a fixed

precision resistor tied to ground in order to establish the correct current.

40, 46

41, 44, 47, 50

CPUCLK[0–3]

42, 45, 48, 51

CPUCLK[0–3]

43, 49

52

SPREAD

Enables spread spectrum mode when held low on differential host outputs,

MREF/MREF_B clocks, 66 MHz clocks, and 33 MHz PCI clocks. Asserts low.

53

54

3VMref_b

3.3 V clock outputs running at 1/2 CPU clock frequency. 66 MHz or 50 MHz depending

on the state of input pin SEL133/100. (Out of phase with 3VMREF output).

55

3VMref

3.3 V clock outputs running at 1/2 CPU clock frequency. 66 MHz or 50 MHz depending

on the state of input pin SEL133/100.

56

3.3 V power supply