I meet a problem on UART4 Rx with DMA. I tried to modify and build driver_examples\uart\edma_transfer in KSDK2.0.
The modifications as following:
PORT_SetPinMux(PORTC, 14U, kPORT_MuxAlt3);
PORT_SetPinMux(PORTC, 15U, kPORT_MuxAlt3);
#define DEMO_UART UART4
#define DEMO_UART_CLKSRC kCLOCK_BusClk
#define UART_TX_DMA_CHANNEL 6U
#define UART_RX_DMA_CHANNEL 7U
#define UART_TX_DMA_REQUEST kDmaRequestMux0UART4
#define UART_RX_DMA_REQUEST kDmaRequestMux0UART4
#define ECHO_BUFFER_LENGTH 8
The test result is: TX is OK, but RX always get same data, g_rxBuffer full fill with the first byte.
I found that when enter DMA IRQ handler first time, UART4 S1[RDRF] is set to 1, then DMA IRQ handler will be called endlessly and RDRF is keep 0.
I also test UART3, it is normal.
Any additional configs are needed for UART4?