How to use UART8 on RT1176

[lfost]

I have a custom board with an rt1176 processor.  Need to use UART8 for RS232/RS485 communication.  I have these parameters set in board.h - 

#define DEBUG_CONSOLE_UART_INDEX 8//1 for normal debug//8 for rs232/rs485

#elif DEBUG_CONSOLE_UART_INDEX == 8
#define BOARD_DEBUG_UART_BASEADDR (uint32_t) LPUART8
#define BOARD_DEBUG_UART_INSTANCE 8U
#define BOARD_UART_IRQ LPUART8_IRQn
#define BOARD_UART_IRQ_HANDLER LPUART8_IRQHandler

I can see outbound data from the micro to the teraterm window.

I type commands in the teraterm window and see nothing.  The hardware checks out.  I can see correct data at the micro RX pin using a scope.

Pins are configured with the standard UART8 RX and TX convention.

I looked down in the driver software and did not see anything else to turn on.  

[jay_heng]

You can use polling way to access LPUART8 under Cortex-M7, as LPUART8 IRQ is only available under Cortex-M4.

Below blog may be helpful to you (it is in chinese):

https://www.cnblogs.com/henjay724/p/16580219.html