External Signals And Pin Multiplexing; Castellated Pad Signals And Multiplexing - Digi ConnectCore 8X Hardware Reference Manual

External signals and pin multiplexing

The following table lists the I/O multiplexing (IOMUX) of the ConnectCore 8X System-on-module. Most of the castellated pads are associated with
(connected to) an LGA pad; this relationship is highlighted in the "Associated LGA Pad name" column.
The microprocessor used on this module, like all CMOS devices, can be driven into a latch-up condition if any I/O pin is driven outside of its
associated power rail. Care must be taken to:
Never drive an I/O pin beyond its positive rail or below ground.
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Never drive an I/O pin from an external power source during the power-on or reset sequences.
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Never hot-swap the module or interrupt its ground connection to external circuitry.
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Latch-up is a condition that can cause excessive current draw and result in excessive heating of the microprocessor or its power supplies. This
excessive heating can permanently damage the microprocessor and/or its supporting components.

Castellated pad signals and multiplexing

Associated
Castellated LGA Pad
pad # name
1 E4
2 E3
ConnectCore 8X
i.MX 8X pin name*
signal name
USDHC1_RESET_B USDHC1_RESET_B
USDHC1_VSELECT USDHC1_VSELECT
Multiplexing
ALT0: USDHC1_RESET_B
ALT1: NAND_RE_N
ALT2: SPI2_SCK
ALT3:
ALT4: GPIO4_IO19
ALT0: USDHC1_VSELECT
ALT1: NAND_RE_P
ALT2: SPI2_SDO
ALT3: NAND_RE_B
ALT4: GPIO4_IO20
Power group Comments
VDD_USDHC1
VDD_USDHC1