Dennis Field / dvk-mx8m-bsb - History

Bring out M.2 signals to the main sheet and attach WoWWAN and RESET

Add notes regarding the WWAN M.2's USB interface. The Emcraft SoM has NAND_CE3_B available for the DISABLE pin. Still need to select which pin will be used for CONFIG_1.

Add sim card slot, ESD protection, and relevant notes regarding the expected M.2 configuration

Add 3.0V LDO for display's VCI and TP_VCC, include a 3~12ms rise time delay for the 1.8V rail to turn on before the 3.0V rail, begin the WWAN M.2 schematic (found a a low-profile key B connector)

Add MIPI DSI, cap touch interface, and AMOLED display regulator circuits

TPS65632's components were selected based on the best match and price based on suggestions. The RT4720 does not seem to be sold by any distributors.

Add JTAG and buttons & LED schematics, reorder based on priority (especially for debugging/development)

Include boot configuration circuit and notes regarding booting from eMMC (USDHC1) vs SD (USDHC2)

Include UART debug interface/header, using a 74LVC2G241 buffer which is 5V tolerant so that either 3.3V or 5V UART cables could be used

Six pin header used so that either 6-pin fixed, 4-pin, or 3-pin cables can be used. Only RX, TX, and GND are used since Vcc, RTS#, and CTS# is unneeded, the other three pins are NC.

Include uSD card schematic, add note about testing 1.8V LDO in place of the buck