Example Description

This example describes how to use UART to communicate with PC.

Required Components:
    USBtoTTL adapter

Connect to PC
 - Connect Ground: connect to GND pin via USBtoTTL adapter
 - Use UART0
	GPIOA_19 as UART0_RX connect to TX of USBtoTTL adapter
	GPIOA_18 as UART0_TX connect to RX of USBtoTTL adapter

Open Super terminal or teraterm and 
set baud rate to 38400, 1 stopbit, no parity, no flow contorl.

This example shows:
User input will be received by demo board, and demo board will loopback the received character with timeout.

Note that buffer length should be integral multiple of 32 bytes, and buffer address should be 32 bytes aligned when using DMA. 