cExpress-BL
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3.3.10.
USB Root Segmentation
3.3.11.
SPI (BIOS only)
Signal
Pin # Description
I/O
PU/PD
Comment
SPI_CS#
B97
Chip select for Carrier Board SPI BIOS Flash.
O 3.3VSB
PU 10K 3.3VSB
SPI_MISO
A92
Data in to module from carrier board SPI BIOS flash.
I 3.3VSB
SPI_MOSI
A95
Data out from module to carrier board SPI BIOS flash.
O 3.3VSB
SPI_CLK
A94
Clock from module to carrier board SPI BIOS flash.
O 3.3VSB
SPI_POWER
A91
Power supply for Carrier Board SPI – sourced from
Module – nominally 3.3V.
The Module shall provide a minimum of 100mA on
SPI_POWER.
Carriers shall use less than 100mA of SPI_POWER.
SPI_POWER shall only be used to power SPI devices
on the Carrier
O P 3.3VSB
BIOS_DIS0# A34
Selection
strap to determine the BIOS boot device.
I
PU 10K 3.3VSB
Carrier shall pull to
GND or leave no-
connect.
BIOS_DIS1# B88
Selection
strap to determine the BIOS boot device.
I
PU 10K 3.3VSB
Carrier shall pull to
GND or leave no-
connect
