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2013
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AG
TU87m12
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Table 15 Miscellaneous Signal Descriptions
Signal
Pin #
Description
I/O
PU/PD
Comment
I2C_CK
B33
General purpose I²C port clock output/input
I/O 3.3V
PU 2K2 3.3VSB
I2C_DAT
B34
General purpose I²C port data I/O line
I/O 3.3V
PU 2K2 3.3VSB
SPKR
B32
Output for audio enunciator, the “speaker” in PC-AT systems
O 3.3V
SPEAKER is a boot strap signal
(see note below)
WDT
B27
Output indicating that a watchdog time-out event has occurred.
O 3.3V
PD 10K
FAN_PWMOUT
B101
Fan speed control. Uses the Pulse Width Modulation (PWM) technique to control
the fan’s RPM.
O OD
3.3V
PU 10K 3.3V
FAN_TACHIN
B102
Fan tachometer input.
I OD
PU 10K 3.3V
Requires a fan with a two pulse
output.
TPM_PP
A96
Physical Presence pin of Trusted Platform Module (TPM). Active high. TPM chip
has an internal pull-down. This signal is used to indicate Physical Presence to the
TPM.
I 3.3V
Trusted Platform Module chip is
optional.
Note
The congatec COM Express Type 6 and Type 10 modules use a Push-Pull output for the fan_pwm signal instead of the open drain output
specified in the COM Express specification. Although this does not comply with the COM Express specification 2.0, the benefits are obvious.
The Push-Pull output optimizes the power consumed by the fan_pwm signal without functional change.
Some signals have special functionality during the reset process. They may bootstrap some basic important functions of the module. For more
information refer to section 9.5 of this user’s guide.
Table 16 General Purpose I/O Signal Descriptions
Signal
Pin # Description
I/O
PU/PD
Comment
GPO0
A93
General purpose output pins.
Shared with SD_CLK. Output from COM Express, input to SD
O 3.3V
SDIO interface is not supported on the conga-TC87
GPO1
B54
General purpose output pins.
Shared with SD_CMD. Output from COM Express, input to SD
O 3.3V
SDIO interface is not supported on the conga-TC87
GPO2
B57
General purpose output pins.
Shared with SD_WP. Output from COM Express, input to SD
O 3.3V
SDIO interface is not supported on the conga-TC87
GPO3
B63
General purpose output pins.
Shared with SD_CD. Output from COM Express, input to SD
O 3.3V
SDIO interface is not supported on the conga-TC87
GPI0
A54
General purpose input pins. Pulled high internally on the module.
Shared with SD_DATA0. Bidirectional signal
I 3.3V
PU 10K 3.3V
SDIO interface is not supported on the conga-TC87
GPI1
A63
General purpose input pins. Pulled high internally on the module.
Shared with SD_DATA1. Bidirectional signal
I 3.3V
PU 10K 3.3V
SDIO interface is not supported on the conga-TC87