ADC Alternate DMA trigger

Table of Contents

• Example Description
  • Configurations
  • ISRs
  • External Connections
  • Watch Variables
• Supported Combinations
• Steps to Run the Example
• See Also
• Sample Output

Example Description

This example showcases the usage of the alternate dma trigger from ADC, in order to trigger DMA once the results have been latched in the result space, instead of triggering the DMA at the end of conversion. ADC_enableAltDMATiming() will enable this trigger.

Configurations

The Example Configures the SOC0 in both ADC0, ADC1 to be triggered by ADC_INT1. The DMA channels 0,1 are configured for triggers from ADC0_INT1, ADC1_INT1 respectively.

ISRs

App_dmach0ISR

• ISR triggered at the end of the DMA transfers to stop ADC SOCs from getting further triggers.

External Connections

ADC0-SOC0 Samples on Channel 2, where as ADC1-SOC0 samples on Channel 0.

• on AM263Px CC E2, with HSEC Dock
  • Feed Analog input to ADC0_AIN2 - HSEC PIN 15
    
  • Feed Analog input to ADC1_AIN0 - HSEC PIN 12
    
• on AM263Px LP
  • Feed Analog Input to the ADC0_AIN2 - J7 Pin 66
  • Feed Analog Input to the ADC1_AIN0 - J3 Pin 24
• on AM261x LP
  • Feed Analog Input to the ADC0_AIN2 - J7 Pin 63
  • Feed Analog Input to the ADC1_AIN0 - J3 Pin 24
• on AM261x SOM with HSEC Dock
  • Feed Analog input to ADC0_AIN2 - HSEC PIN 15
    
  • Feed Analog input to ADC1_AIN0 - HSEC PIN 12
    

Watch Variables

gAdc0DataBuffer[] - Buffer to store ADC0 SOC0 results, copied by DMA. gAdc1DataBuffer[] - Buffer to store ADC1 SOC0 results, copied by DMA.

Supported Combinations

Parameter	Value
CPU + OS	r5fss0-0 nortos
Toolchain	ti-arm-clang
Board	am263px-cc, am263px-lp
Example folder	examples/drivers/adc/adc_alternate_dma_trigger/

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 Alternate DMA trigger Test Started ...
ADC1 : ADC2 Result register value -
4095 : 1082
4095 : 1056
4095 : 1071
4095 : 1083
4095 : 1091
4095 : 1055
4095 : 1056
4095 : 1081
4095 : 1091
4095 : 1054
4095 : 1078
ADC Alternate DMA trigger Test Passed
All tests have passed!!