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2012
congatec
AG
TCEDm10
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7.5
Boot Strap Signals
Table 28 Boot Strap Signal Descriptions
Signal
Pin # Description of Boot Strap Signal
I/O
PU/PD Comment
AC/HDA_SYNC
A29
High Definition Audio Sync:
This signal is a 48 kHz fixed rate sample
sync to the codec(s). It is also used to encode the stream number.
O 3.3VSB
AC/HDA_SYNC is a boot strap signal
(see caution statement below)
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 Mb/s for High Definition Audio.
O 3.3VSB
AC/HDA_SDOUT is a boot strap signal
(see caution statement below)
LVDS_I2C_DAT
A84
DDC lines used for flat panel detection and control.
I/O 3.3V
PU 2k2
3.3V
LVDS_I2C_DAT is a boot strap signal
(see caution statement below).
SPKR
B32
Output for audio enunciator, the “speaker” in PC-AT systems
O 3.3V
PD 1k
SPKR is a boot strap signal (see caution
statement below)
EXCD0_PERST#
A48
ExpressCard 0 Reset
O 3.3V
PD 2.2k EXCD0_PERST# is a boot strap signal
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 caution statement 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 caution statement below).
LPC_CLK
B10
LPC clock output - 33MHz nominal
O 3.3V
PD 10k LPC_CLK is a bootstrap signal (see
caution statement 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.