Datasheet

Intel® Xeon® Processor D-1500 Product Family and System Clocks
36 Intel® Xeon® Processor D-1500 Product Family
Datasheet - Volume 1 of 4: Integrated Platform Controller Hub
March 2015
A summary is given in the following tables; Ta b l e 2- 1 shows the system clock input to
Intel® Xeon® Processor D-1500 Product Family. Ta bl e 2- 2 shows system clock outputs
generated by Intel® Xeon® Processor D-1500 Product Family.
Table 2-1. SoC Clock Inputs
Clock Domain Frequency Usage description
CLKIN_GND2_P/N N/A Unused. Tie each signal to GND through a 10 KΩ resistor.
CLKIN_GND3_P/N N/A Unused. Tie each signal to GND through a 10 KΩ resistor.
CLKIN_GND4_P/N N/A Unused. Tie each signal to GND through a 10 KΩ resistor.
CLKIN_GND_P/N N/A Unused. Tie each signal to GND through a 10 KΩ resistor.
CLKIN_33MHZLOOPBACK 33 MHz 33 MHz clock feedBack input to reduce skew between Intel®
Xeon® Processor D-1500 Product Family 33MHz clocks and
buses such as LPC. This signal must be connected to one of
the pins in the group CLKOUT_33MHz[4:0]
REFCLK14IN 14.31818
MHz
Unused. Tie signal to GND through a 10 KΩ resistor.
XTAL25_IN 25 MHz Crystal input source used by Intel® Xeon® Processor D-
1500 Product Family.
Table 2-2. Clock Outputs
Clock Domain Frequency
Spread
Spectrum
Usage
CLKOUT_33MHz[4:0] 33 MHz Yes Single Ended 33 MHz outputs. One of these
signals must be connected to
CLKIN_33MHZLOOPBACK to function as
a clock loopback. This allows skew control
for variable lengths of
CLKOUT_33MHz[4:0].
CLKOUT_PCIE[7:0]_P/N 100 MHz Yes 100 MHz PCIe 2.0 specification compliant
differential output to PCI Express devices.
CLKOUT_PEG_A_P/N
CLKOUT_PEG_B_P/N
100 MHz Yes 100 MHz PCIe 3.0 specification compliant
differential outputs to PCI Express Graphics
devices.
CLKOUT_ITPXDP_P/N 100 MHz Yes Primarily used as 100 MHz Clock to
processor XDP/Intel ITP on the platform or
can be configured as CLKOUT_PEG_C_P/N.
CLKOUTFLEX1/ GPIO65
CLKOUTFLEX3/ GPIO67
33 MHz /
14.31818 MHz
/ 48 MHz /
24 MHz
Yes Programmable 33 MHz, 48/24 MHz or
14.31818 MHz outputs for various platform
devices.
SPI_CLK 17.86 MHz /
31.25 MHz /
50 MHz
No Drive SPI devices connected to Intel®
Xeon® Processor D-1500 Product Family.
Generated by Intel® Xeon® Processor D-
1500 Product Family.
XTAL25_OUT 25 MHz No Crystal output source by Intel® Xeon®
Processor D-1500 Product Family.