Spi (bios only), Miscellaneous – ADLINK Express-IBE2 User Manual
Page 23

Express-IBE2
Page 23
3.3.10. 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
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 3.3V
Carrier shall pull to GND 
or leave unconnected 
BIOS_DIS1#
B88
Selection strap to determine the BIOS boot device.
I
PU 10K 3.3V
Carrier shall pull to GND 
or leave unconnected 
3.3.11. Miscellaneous
Signal
Pin
Description
I/O
PU/PD
Comment
SPKR
B32
Output for audio enunciator, the “speaker” in PC-AT 
systems. 
O 3.3V
WDT
B27
Output indicating that a watchdog time-out event has 
occurred. 
O 3.3V
KBD_RST#
A86
Input to module from (optional) external keyboard 
controller which can force a reset. Pulled high on the 
module. This is a legacy artifact of the PC-AT. 
I 3.3V
PU 10K 3.3V
KBD_A20GATE
A87
Input to module from (optional) external keyboard 
controller which can be used to control the CPU A20 gate 
line. The A20GATE restricts the memory access to the 
bottom megabyte and is a legacy artifact of the PC-AT. 
Pulled low on the module. 
I 3.3V
PU 10K 3.3V
THRM#
B35
Input from off-module temp sensor indicating an over-temp 
situation. 
I 3.3V
THERMTRIP#
A35
Active low output indicating the CPU has entered thermal 
shutdown. 
O 3.3V
TPM_PP11
C83
Trusted Platform Module (TPM) Physical Presence pin. 
Active high. TPM chip has an internal pull down. This 
signal is used to indicate Physical Presence to the TPM. 
I 3.3V
PD 3.3V
If TPM not installed on 
module, remove PD 
3.3V 
