Boot Strap Signals; Table 30 Boot Strap Signal Descriptions - Congatec COM Express conga-TC87 User Manual

9.5

Boot Strap Signals

Table 30 Boot Strap Signal Descriptions
Signal
AC/HDA_SDOUT
SPKR
DDI1_CTRLDATA_AUX-
DP1_AUX-
HDMI_CTRLDATA
DDI2_CTRLDATA_AUX-
DP2_AUX-
HDM2_CTRLDATA
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.
Copyright © 2013 congatec AG
Pin # Description of Boot Strap Signal
High Definition Audio Serial Data Out: This signal is the serial TDM data
A33
output to the codec(s). This serial output is double-pumped for a bit rate of 48
Mb/s for High Definition Audio.
B32 Output for audio enunciator, the "speaker" in PC-AT systems
Multiplexed with DP1_AUX- and HDMI1_CTRLDATA.
D16
DP AUX- function if DDI1_DDC_AUX_SEL is no connect.
HDMI/DVI I2C CTRLDATA if DDI1_DDC_AUX_SEL is pulled high.
Multiplexed with DP2_AUX- and HDMI2_CTRLDATA.
C33
DP AUX- function if DDI2_DDC_AUX_SEL is no connect.
HDMI/DVI I2C CTRLDATA if DDI2_DDC_AUX_SEL is pulled high.
TU87m12
I/O PU/PD Comment
AC/HDA_SDOUT is a boot strap
O 3.3VSB PU 1K
3.3VSB signal (see caution statement below)
O 3.3V SPKR is a boot strap signal (see
caution statement below)
DDI1_CTRLDATA_AUX- is a boot
PU100k
I/O PCIE 3.3V strap signal (see not below).
I/O OD 3.3V
DDI2_CTRLDATA_AUX- is a boot
PU100k
I/O PCIE 3.3V strap signal (see not below).
I/O OD 3.3V
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