ADLINK cExpress-BT - Manual (Page 23)

cExpress-BT Page 23
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 3.3V
THRMTRIP# A35 Active low output indicating that the CPU has entered
thermal shutdown. O 3.3V PU 10k 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
FAN_TACHIN B102 Fan tachometer input for a fan with a two pulse output. I OD 3.3V PU 10k 3.3V
TPM_PP 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 10k 3.3V
PD only when TPM on
module
3.3.13. SMBus
Signal Pin # Description I/O PU/PD Comment
SMB_CK B13 System Management Bus bidirectional clock line. Power
sourced through 5V standby rail and main power rails. I/O OD 3.3VSB PU 2k2 3.3VSB
SMB_DAT# B14 System Management Bus bidirectional data line. Power
sourced through 5V standby rail and main power rails. I/O OD 3.3VSB PU 2k2 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 5V standby rail and main power rails. I 3.3VSB PU 10k 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 or
Baytrail SOC as
alternative.
I2C_DAT B34 General purpose I²C port data I/O line I/O OD 3.3VSB PU 2k2 3.3VSB Source SEMA BMC or
Baytrail SOC as
alternative.
3.3.15. General Purpose I/O (GPIO)
Signal Pin # Description I/O PU/PD Comment
GPO[0] A93 General purpose output pins. O 3.3V PU 10K 3.3V After hardware RESET
output low
GPO[1] B54 General purpose output pins. O 3.3V PU 10K 3.3V After hardware RESET
output low
GPO[2] B57 General purpose output pins. O 3.3V PU 10K 3.3V After hardware RESET
output low