ADC SOC Continuous DMA

Table of Contents

• Introduction
• External Connections
  • AM263X-CC
  • AM263X-LP
• Supported Combinations
• Steps to Run the Example
• See Also
• Sample Output

Introduction

This example sets up two ADC channels to convert simultaneously. The results will be transferred by DMA into a buffer in RAM.

Module Block diagram

The example does the below

• Configures ePWM0 to trigger SOC0 on ADC0 and ADC1. This is used to trigger the first ADC conversion.
• INT0 of ADC0 is configured to generate interrupt after first conversion and will then disable EPWM SOC generation.
• Configure ADC INT1 of both ADC's to enable continuous conversion. The interrupts will act as trigger for next conversions.
• Configure DMA channel 0 to be triggered at EOC0 of ADC0 and copy conversion result to a buffer in RAM.
• Configure DMA channel 1 to be triggered at EOC0 of ADC1 and copy conversion result to another buffer in RAM.
• Configure DMA to generate interrupt after the buffer is filled and stop conversion on both ADC's.
• The DMA destination buffers (watch variables) can be used to view the ADC conversion results.

Watch Variables

• gAdc0DataBuffer, gAdc1DataBuffer - Digital representation of the voltage on pin ADC0_AIN0 and ADC1_AIN0

External Connections

• ADC0_AIN0 and ADC1_AIN0 pin should be connected to the signals to be converted.

AM263X-CC

When using AM263x-CC with TMDSHSECDOCK (HSEC180 controlCARD Baseboard Docking Station)

• Feed analog inputs (non-zero voltage) to HSEC Pin 12 and HSEC Pin 18

AM263X-LP

When using AM263x-LP

• Feed analog inputs (non-zero voltage) to boosterpack header J1/J3 Pin 23 and J1/J3 Pin 24.

Supported Combinations

Parameter	Value
CPU + OS	r5fss0-0 nortos
Toolchain	ti-arm-clang
Board	am263x-cc, am263x-lp
Example folder	examples/drivers/adc/adc_soc_continuous_dma/

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 Using SDK with CCS Projects).
• When using makefiles to build, note the required combination and build using make command (see Using SDK with Makefiles)
• Establish connections as mentioned in External Connections section
• Launch a CCS debug session and run the executable, see CCS Launch, Load and Run
• Using watch variables, view the ADC conversion results.
• View the ADC conversion results in UART console logs

See Also

ADC

Sample Output

Shown below is a sample output when the application is run,

ADC Continuous DMA transfer Test Started ...
ADC0 : ADC1 Result register value -
3329 : 3362
1048 : 1072
1046 : 1082
1063 : 1042
1083 : 1059
1065 : 1041
1064 : 1059
1083 : 1082
1061 : 1071
1083 : 1059
1073 : 1072
ADC Continuous DMA transfer Test Passed
All tests have passed!!