AM625: AM625 HW design issues

Hello Ethan, 

Thank you for the Query. 

Please refer my inputs below 

1.The touch panel is an I2C interface. Which I2C is the best way to connect? And about touch interrupt, is it possible to use pin A15?

Please consider using any I2C interface in the main domain. SoC_I2C0 is used in the EVM. 

2.LCD backlight dim control, which IO should be used to output PWM? Can the C13 pin of the AM6254 be used?
Currently unused ePWM pins are: B14, C13, A13, A14, B18, B13, E18.

This should be fine 

3.The external GPS module is a serial port interface. Which one of the following two serial ports is better?
MCU_UART0
WKUP_UART0

Please refer below section and confirm if there are any Main Domain that you could use.

6.3.25 UART
6.3.25.1 MAIN Domain

Regarding the use of MCU UART please refer below thread.

(+) AM625: MAIN, MCU and WKUP Domain Communication Interfaces of AM6252 - Processors forum - Processors - TI E2E support forums

I am not sure on the use of WKUP UART for user application. I will have to check internally.

Regards,

Sreenivasa