Datasheet
Intel® Xeon® Processor D-1500 Product Family and System Clocks
Intel® Xeon® Processor D-1500 Product Family 43
Datasheet - Volume 1 of 4: Integrated Platform Controller Hub
March 2015
2.5.1.9 DCOSS—Differential Clock Out Source Select Register
Attribute: R/W
Default Value: 00000400h Size: 32-bit
2.5.1.10 SECOSS—Single Ended Clock Out Source Select Register
Attribute: R/W
Default Value: 00002516h Size: 32-bit
4 CLKOUT_33MHz_1 Clock Buffer Resistance Selection — R/W. This parameter controls Single/
Double load series resistance.
0 = 25 Ω single load usage
1 = 17 Ω double load usage (Default).
3:1 CLKOUT_33MHz_0 Clock Buffer Slew Rate Selection — R/W. This parameter controls slew
rate of 33 MHz clock 0. Each bit step change corresponds to ~0.2 V/ns.
000 = 0.6 V/ns minimum
100 = 1.4 V/ns (Default)
111 = 2.0 V/ns maximum
0 CLKOUT_33MHz_0 Clock Buffer Resistance Selection — R/W. This parameter controls Single/
Double load series resistance.
0 = 25 Ω single load usage
1 = 17 Ω double load usage (Default)
Bit Description
Bit Description
31:10 Reserved
9:8 Reserved
7:6 CLKOUT_PEGB Source Select — R/W. This parameter selects the source of clock to be driven
out on CLKOUT_PEGB. When not over-clocking this output should be sourced by the PCIe clock
source MODIV3.
00 = Non-Overclockable source MODIV3 (Default)
01 = Reserved
10 = Reserved
11 = Reserved
5:4 CLKOUT_PEGA Source Select — R/W. This parameter selects the source of clock to be driven
out on CLKOUT_PEGA. When not over-clocking this output should be sourced by the PCIe clock
source MODIV3.
00 = Non-Overclockable source MODIV3 (Default)
01 = Reserved
10 = Reserved
11 = Reserved
3:0 Reserved
Bit Description
31:15 Reserved
14:12 CLKOUTFLEX3 Source Select — R/W. This field selects the source of clock to be driven out on
CLKOUTFLEX3.
000 = 33.33 MHz Clock Source
001 = 14.31818 MHz Clock Source
010 = 48/24 MHz Clock Source (Default)
All other values are not supported.
11:7 Reserved
6:4 CLKOUTFLEX1 Source Select — R/W. This field selects the source of clock to be driven out on
CLKOUTFLEX1.
000 = 33.33 MHz Clock Source
001 = 14.31818 MHz Clock Source (Default)
010 = 48/24 MHz Clock Source
All other values are not supported.