ADLINK Technology COM Express Express-CFR, User Manual

Page: 27 / 108

Express-CFR
Pinouts and Signal Descriptions
21
3.3.12. 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
THRM# B35 Input from off-module temp sensor indicating an
over-temp situation. I 3.3VSB
THRMTRIP# A35 Active low output indicating that the CPU has
entered thermal shutdown. O 3.3V
FAN_PWMOUT B101 Fan speed control. Uses the Pulse Width
Modulation (PWM) technique to control the fan’s
RPM.
O OD 3.3V PU 2.2K
3.3V
There shall be PD
on carrier board
FAN_TACHIN B102 Fan tachometer input for a fan with a two pulse
output. I OD 3.3V PU 47K
3.3V
TPM_PP A96 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 100K
PD only when TPM
on module.
Modules
implementing a
TPM shall pull
down TPM_PP.
3.3.13. SMBus
Signal Pin # Description I/O PU/PD Comment
SMB_CK B13 System Management Bus bidirectional clock
line. Power sourced through 3.3V standby
rail and main power rails. I/O OD
3.3VSB PU 2.2K
3.3VSB
SMB_DAT# B14 System Management Bus bidirectional data
line. Power sourced through 3.3V standby
rail and main power rails.
I/O OD
3.3VSB PU 2.2K
3.3VSB
SMB_ALERT# B15 System Management Bus Alert – active low
input can be used to generate an SMI#
(System Management Interrupt) or to wake
the system. Power sourced through 3.3V
standby rail and main power rails.
I 3.3VSB
3.3.14. I2C Bus
Signal Pin # Description I/O PU/PD Comment
I2C_CK B33 General purpose I²C port clock output/input I/O OD
3.3VSB PU 2K2
3.3VSB Source SEMA BMC
as default (chipset
by build option)
I2C_DAT B34 General purpose I²C port data I/O line
I/O OD
3.3VSB PU 2K2
3.3VSB Source SEMA BMC
as default (chipset
by build option)