UART Internal Loopback with DMA

Table of Contents

• Introduction
• Watch Variables
• External Connections
• Steps to Run the Example
• See Also

Introduction

This program uses the internal loopback test mode of the UART module. Both DMA interrupts and UART FIFOs are used. When the UART transmit FIFO has enough space (as indicated by its FIFO level interrupt signal), the DMA will transfer data from global variable sData into the FIFO. This will be transmitted to the receive FIFO via the internal loopback.

When enough data has been placed in the receive FIFO (as indicated by its FIFO level interrupt signal), the DMA will transfer the data from the FIFO into global variable rData.

When all data has been placed into rData, a check of the validity of the data will be performed in one of the DMA channels' ISRs.

Note

Avoid keeping the memory browser open while the execution is in progress.

Watch Variables

• sData : Data to send
• rData : Received data

External Connections

• None

Steps to Run the Example

• When using CCS projects to build, import the CCS project for the required combination and build it using the CCS project menu (see CCS Build Project).
• When using makefiles to build, note the required combination and build using make command (see Makefile based Build)
• Establish connections as mentioned in External Connections section.
• Launch a CCS debug session and run the executable, see Build, Load and Run
• Once DMA operations are complete and program hits ESTOP, inspect received data

See Also

UART