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2017
congatec
AG
TCKLm10
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8.5
Boot Strap Signals
Table 36 Boot Strap Signal Descriptions
Signal
Pin # Description of Boot Strap Signal
I/O
PU/PD Comment
AC/HDA_SDOUT
A33
High Definition Audio Serial Data Out: This signal is the serial TDM
data output to the codec(s). This serial output is double-pumped for
a bit rate of 48 Mbps for High Definition Audio.
O 3.3VSB
PU 1K
3.3VSB
AC/HDA_SDOUT is a boot strap
signal (see caution statement below)
SPKR
B32
Output for audio enunciator, the “speaker” in PC-AT systems
O 3.3V
SPKR is a boot strap signal (see
caution statement below)
DDI1_CTRLDATA_AUX-
DP1_AUX-
HDMI_CTRLDATA
D16
Multiplexed with DP1_AUX- and HDMI1_CTRLDATA.
DP AUX- function if DDI1_DDC_AUX_SEL is no connect.
HDMI/DVI I2C CTRLDATA if DDI1_DDC_AUX_SEL is pulled high.
I/O PCIE
I/O OD 3.3V
PU100k
3.3V
DDI1_CTRLDATA_AUX- is a boot
strap signal (see not below).
DDI2_CTRLDATA_AUX-
DP2_AUX-
HDM2_CTRLDATA
C33
Multiplexed with DP2_AUX- and HDMI2_CTRLDATA.
DP AUX- function if DDI2_DDC_AUX_SEL is no connect.
HDMI/DVI I2C CTRLDATA if DDI2_DDC_AUX_SEL is pulled high.
I/O PCIE
I/O OD 3.3V
PU100k
3.3V
DDI2_CTRLDATA_AUX- is a boot
strap signal (see not below).
Caution
The signals listed in the table above are used as chipset configuration straps during system reset. In this condition (during reset), they are
inputs that are pulled to the correct state by either COM Express™ internally implemented resistors or chipset internally implemented
resistors that are located on the module. No external DC loads or external pull-up or pull-down resistors should change the configuration of
the signals listed in the above table.
External resistors may override the internal strap states and cause the COM Express™ module to malfunction and/or cause irreparable
damage to the module.
