Can you clarify what do you mean by CyU3PUartTransmitBytes does not work? You are supposed to call this after the channel is configured? Why do you want to transmit data before the channel is configured? You have mentioned tha the UART data transfer is working, but CyU3PUartTransmitBytes does not work. Can you clarify the scenario in detail? "My requirement is that even before the reception of data , the external peripheral needs to be configured">> thats ok, you configure the external processor and then start the UART transfers.
While the UART is configured in DMA mode , the api CyU3PUartTransmitBytes cannot be used as stated by the FX3 API documentation. From this my understanding is that in DMA mode only the reception over RX lines of UART is possible ?If this is the case then what is the way to write onto TX lines of UART in DMA mode?