9FG430_17 Datasheet, PDF (15/18 Pages) Integrated Device Technology – Four Output Differential Frequency Generator for PCIe Gen3 and QPI

9FG430
Four Output Differential Frequency Generator for PCIe Gen3 and QPI
SMBus Table: PLL Frequency Control Register
Byte 11
Pin #
Name
Control Function
Bit 7
-
PLL N Div7
Bit 6
-
PLL N Div6
Bit 5
-
Bit 4
-
Bit 3
-
Bit 2
-
PLL N Div5
PLL N Div4
PLL N Div3
PLL N Div2
N Divider Programming
Byte11 bit(7:0) and Byte10
bit(7:6)
Bit 1
-
PLL N Div1
Bit 0
-
PLL N Div0
Type
0
1
Default
RW _{The decimal representation of M}
X
RW and N Divider in Byte 10 and 11 will X
RW ^{configure the PLL VCO frequency.} X
RW ^{Default at power up = latch-in or}
X
Byte 0 Rom table. VCO Frequency
RW
= fXTAL x [NDiv(9:0)+8] /
X
RW _{[MDiv(5:0)+2]. The user does NOT} X
RW need to program these resgisters X
RW
for standard frequencies.
X
SMBus Table: PLL Spread Spectrum Control Register
Byte 12
Pin #
Name
Control Function
Bit 7
-
PLL SSP7
Bit 6
-
PLL SSP6
Bit 5
-
PLL SSP5
Bit 4
-
Bit 3
-
PLL SSP4
PLL SSP3
Spread Spectrum
Programming bit(7:0)
Bit 2
-
PLL SSP2
Bit 1
-
PLL SSP1
Bit 0
-
PLL SSP0
Type
RW
RW
RW
RW
RW
RW
RW
RW
0
1
These Spread Spectrum bits in
Byte 12 and 13 will program the
spread pecentage of PLL. The
user does not need to modify
these settings unless non-
standard spread amounts are
required. The part defaults to -
0.5% spread when spread is
enabled.
Default
X
X
X
X
X
X
X
X
SMBus Table: PLL Spread Spectrum Control Register
Byte 13
Pin #
Name
Control Function
Bit 7
-
Reserved
Bit 6
-
PLL SSP14
Bit 5
-
PLL SSP13
Bit 4
-
Bit 3
-
Bit 2
-
PLL SSP12
PLL SSP11
PLL SSP10
Spread Spectrum
Programming bit(14:8)
Bit 1
-
PLL SSP9
Bit 0
-
PLL SSP8
Type
RW
RW
RW
RW
RW
RW
RW
0
1
These Spread Spectrum bits in
Byte 12 and 13 will program the
spread pecentage of PLL. The
user does not need to modify
these settings unless non-
standard spread amounts are
required. The part defaults to -
0.5% spread when spread is
enabled.
Default
0
X
X
X
X
X
X
X
IDT^® Four Output Differential Frequency Generator for PCIe Gen3 and QPI
15
1681D—04/04/17