w83196s-14 Winbond Electronics Corp America, w83196s-14 Datasheet - Page 6

• Manufacturer Part Number: w83196s-14
• Description: 100 Mhz Clock For Bx Chipset 2 Chip
• Manufacturer: Winbond Electronics Corp America

Set R/W to 1 when read back the data sequence is as follows:
7.3 Serial Control Registers
The Pin column lists the affected pin number and the @PowerUp column gives the state at true
power up. Registers are set to the values shown only on true power up. "Command Code" byte and
"Byte Count" byte must be sent following the acknowledge of the Address Byte. Although the data
(bits) in these two bytes are considered "don't care", they must be sent and will be acknowledge. After
that, the below described sequence (Register 0, Register 1, Register 2, ....) will be valid and
acknowledged.
Register 0 to Register 2 are referred to the Winbond SDRAM buffer(W83178S/179J) drivers.
7.3.1 Register 3: CPU Frequency Select Register (1 = Enable, 0 = Stopped)
(I) Default Frequency table selection by software via I
SSEL2
Clock Address
A(6:0) & R/W
BIT
1-0
7
6
5
4
3
2
0
0
0
0
1
1
1
1
@POWERUP
SSEL1
00
0
0
1
1
0
0
1
1
0
0
0
0
0
0
Ack
SSEL0
0
1
0
1
0
1
0
1
PIN
Byte 0
-
-
-
-
-
-
-
CPU, SDRAM (MHZ)
Reserved
SSEL2 ( Frequency table selection by software via I
SSEL1 ( Frequency table selection by software via I
SSEL0 ( Frequency table selection by software via I
0 = Selection by SEL100/66#
1 = Selection by software I
Reserved
Bit1
0
0
1
1
Bit0 (See Function Table)
133.3
68.5
83.3
66.8
Ack
103
112
100
0
1
0
1
75
- 6 -
Normal
Test Mode
Tristate
0.5% center type Spread Spectrum enabled
Byte 1
2
C (When Register 7 Bit 0 = 0 )
Preliminary W83196S-14
DESCRIPTION
2
PCI (MHZ)
C - Bit 6:4 and Register 7 Bit0
34.25
34.25
44.43
37.5
41.6
33.4
37.3
33.3
Ack
Byte2, 3, 4...
until Stop
REF2X (MHZ)
14.318
14.318
14.318
14.318
14.318
14.318
14.318
14.318
2
2
2
C)
C)
C)