Preliminary W83193R-02/-04/-04A

Publication Release Date: April 1999

- 7 -

Revision A1

8.3.1 Register 0: CPU Frequency Select Register (1 = Enable, 0 = Stopped)

BIT

@POWERUP

PIN

DESCRIPTION

7

0

-

0 =

±1.5% Spread Spectrum Modulation

1 =

±0.5% Spread Spectrum Modulation

6

0

-

SSEL2 (Frequency table selection by software via I

5

0

-

SSEL1 (Frequency table selection by software via I

4

0

-

SSEL0 (Frequency table selection by software via I

3

0

-

0 = Selection by hardware

1 = Selection by software I

2

0

-

0 = Spread Spectrum center spread type

1 = Spread Spectrum down spread type

1

0

-

0 = Normal

1 = Spread Spectrum enabled

0

0

-

0 = Running

1 = Tristate all outputs

Frequency table selection by software via I

SSEL2

SSEL1

SSEL0

CPU, SDRAM (MHz)

PCI (MHz)

REF, IOAPIC (MHz)

0

0

0

50

25

14.318

0

0

1

75

32

14.318

0

1

0

83.3

41.65

14.318

0

1

1

68.5

34.25

14.318

1

0

0

83.3

33.3

14.318

1

0

1

75

37.5

14.318

1

1

0

60

30

14.318

1

1

1

66.8

33.4

14.318

FUNCTION TABLE

FUNCTION

OUTPUTS

DESCRIPTION

CPU

PCI

SDRAM

REF

IOAPIC

TRI-STATE

Hi-Z

Hi-Z

Hi-Z

Hi-Z

Hi-Z

NORMAL

See table

See table

CPU

14.318

14.318