954226 Datasheet, PDF (12/22 Pages) Integrated Device Technology – Programmable Timing Control HubTM for Mobile P4TM Systems

954226
Programmable Timing Control Hub^TM for Mobile P4^TM Systems
SMBus Table: VCO Frequency Control Register
Byte 12
Pin #
Name
Bit 7
-
Bit 6
-
Bit 5
-
Bit 4
-
Bit 3
-
Bit 2
-
Bit 1
-
Bit 0
-
N Div7
N Div6
N Div5
N Div4
N Div3
N Div2
N Div1
N Div0
SMBus Table: Spread Spectrum Control Register
Byte 13
Pin #
Name
Bit 7
-
Bit 6
-
Bit 5
-
Bit 4
-
Bit 3
-
Bit 2
-
Bit 1
-
Bit 0
-
SSP7
SSP6
SSP5
SSP4
SSP3
SSP2
SSP1
SSP0
SMBus Table: Spread Spectrum Control Register
Byte 14
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Pin #
-
-
-
-
-
-
-
-
Name
Reserved
SSP14
SSP13
SSP12
SSP11
SSP10
SSP9
SSP8
SMBus Table: Output Divider Control Register
Byte 15
Pin #
Name
Bit 7
-
Bit 6
-
Bit 5
-
Bit 4
-
Bit 3
-
Bit 2
-
Bit 1
-
Bit 0
-
PCIEX Div3
PCIEX Div2
PCIEX Div1
PCIEX Div0
CPU Div3
CPU Div2
CPU Div1
CPU Div0
Control
Function
N Divider Programming
b(8:0)
Type
0
1
RW
RW _{The decimal representation of M and N}
RW Divier in Byte 11 and 12 will configure the
RW VCO frequency. Default at power up =
RW
latch-in or Byte 0 Rom table. VCO
RW
Frequency = 14.318 x [NDiv(9:0)+8] /
RW
[MDiv(5:0)+2]
RW
PWD
X
X
X
X
X
X
X
X
Control
Function
Spread Spectrum
Programming b(7:0)
Type
RW
RW
RW
RW
RW
RW
RW
RW
0
1
These Spread Spectrum bits in Byte 13
and 14 will program the spread
pecentage. It is recommended to use
ICS Spread % table for spread
programming.
PWD
X
X
X
X
X
X
X
X
Control
Function
Reserved
Spread Spectrum
Programming b(14:8)
Type
R
RW
RW
RW
RW
RW
RW
RW
0
1
-
-
These Spread Spectrum bits in Byte 13
and 14 will program the spread
pecentage. It is recommended to use
ICS Spread % table for spread
programming.
PWD
0
X
X
X
X
X
X
X
Control
Function
PCIEX Divider Ratio
Programming Bits
CPUDivider Ratio
Programming Bits
Type
0
1
RW 0000:/2 0100:/4 1000:/8 1100:/16
RW 0001:/3 0101:/6 1001:/12 1101:/24
RW 0010:/5 0110:/10 1010:/20 1110:/40
RW 0011:/15 0111:/30 1011:/60 1111:/120
RW 0000:/2 0100:/4 1000:/8 1100:/16
RW 0001:/3 0101:/6 1001:/12 1101:/24
RW 0010:/5 0110:/10 1010:/20 1110:/40
RW 0011:/15 0111:/30 1011:/60 1111:/120
PWD
X
X
X
X
X
X
X
X
IDT^® Programmable Timing Control Hub^TM for Mobile P4^TM Systems
12
0930A—04/13/10