ADC High Priority SOC

Table of Contents

• Introduction
  • High Priority SOC Configuration :
  • Configurations
• External Connections
• Supported Combinations
• Steps to Run the Example
• See Also
• Sample Output

Introduction

This example showcases the feature "High Priority SOC configuration"

Conversions timing diagram

High Priority SOC Configuration :

• When the SOC are configured in high priority (SOC0 through SOCx) the other SOC are configured in the Round Robin mode.
• The high priority SOC, when triggered, pre-empts the Round Robin Priority.
• If two or more High Priority SOC are triggered at same time, the SOC with lower number precedences.

Configurations

• Triggers from EPWM0 are configured through Syscfg.
• the counter is configured in Stop and Freeze mode.
• the example has to change the Counter mode to get the counter running and EPWM0 can generate triggers to ADC.
• NOTE
  • PPB Delay Time Stamp cannot be used if the SOC trigger is software. hence, the example uses EPWM0 to trigger SOC conversions.
  • This example intends to showcase the Priority modes in the SOC. the input channels can be configured through Syscfg as per need.
• ADC0 (done through Syscfg)
  • SOC 0-3 are in Round Robin (no high priority selected)
  • all SOC are triggered by EPWM0SOCA signal.
  • Conversion sequence : SOC 0 --> SOC 1 --> SOC 2 --> SOC 3
• ADC1 (done through Syscfg)
  • SOC 0-3 are in Round Robin (no high priority selected)
  • SOC 1,2 are triggered by EPWM0SOCA signal.
  • SOC 0,3 are triggered by EPWM0SOCB signal.
  • Conversion sequence : SOC 1 --> SOC 2 --> SOC 3 --> SOC 0
• ADC2 (done through Syscfg)
  • SOC 0-3 are in High Priority (SOC 4-15 are in low priority mode by default)
  • all SOC are triggered by EPWM0SOCA signal.
  • Conversion sequence : SOC 0 --> SOC 1 --> SOC 2 --> SOC 3
• ADC3 (done through Syscfg)
  • SOC 0-3 are in High Priority (SOC 4-15 are in low priority mode by default)
  • SOC 1,2 are triggered by EPWM0SOCA signal.
  • SOC 0,3 are triggered by EPWM0SOCB signal.
  • Conversion sequence : SOC 1 --> SOC 2 --> SOC 0 --> SOC 3
• ADC4 (done through Syscfg)
  • SOC 0 are in High Priority (SOC 1-15 are in low priority mode by default)
  • SOC 0-3 are triggered by EPWM0SOCA signal.
  • Conversion sequence : SOC 0 --> SOC 1 --> SOC 2 --> SOC 3
• ADC4 (reset and done through the code for reference. Can also be set from syscfg)
  • SOC 0 are in High Priority (SOC 1-15 are in low priority mode by default)
  • SOC 1,2 are triggered by EPWM0SOCA signal.
  • SOC 0,3 are triggered by EPWM0SOCB signal.
  • Conversion sequence : SOC 1 --> SOC 2 --> SOC 0 --> SOC 3

PPB Configurations :

• (done through Syscfg for ADC 0-3. done through Code below for ADC 4 for reference)
• All PPBx in ADCy are configured for respective SOCx for delay in trigger to signal capture.

The example does the below

• Configures SOC0,1,2 of ADC0, as high priority SOCs, to be triggered by EPWM0.
• Configures ADC interrupt 0 to be generated at end of conversion of SOC12.
• ADC0 Interrupt ISR is used to read results of ADC0 from SOC0,SOC1 and average of SOC12 through SOC15.

Watch Variables

• The watch variables gAdc0PpbDelay, gAdc1PpbDelay, gAdc2PpbDelay, gAdc3PpbDelay, gAdc4PpbDelay, gAdc4PpbDelay_case2 storing ADC conversion delays can be used to view the respective delays for the SOCs configured.

External Connections

• For this example demonstration, SOCs in respective ADCs are configured for Channel 0 (arbitrarily, any channel can be selected).

Supported Combinations

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

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)
• (optional) Establish connections as mentioned in External Connections section.
• Launch a CCS debug session and run the executable, see CCS Launch, Load and Run
• Using the 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 High Priority SOC Test Started ...
 
ADC0: All SOC in round robin. All SOC triggered by EPWM0SOCA
Expected: delay(SOC0)<delay(SOC1)<delay(SOC2)<delay(SOC3)
delay(SOC0) delay(SOC1) delay(SOC2) delay(SOC3)
2       59      116     173
2       59      116     173
 
ADC1: All SOC in round robin. SOC1,2 triggered by EPWM0SOCA.SOC0,3 triggered by EPWM0SOCB
Expected: delay(SOC1)<delay(SOC2) delay(SOC3)<delay(SOC0)
delay(SOC0) delay(SOC1) delay(SOC2) delay(SOC3)
59      2       59      2
59      2       59      2
 
ADC2: All SOC in high Priority. All SOC triggered by EPWM0SOCA
Expected: delay(SOC0)<delay(SOC1)<delay(SOC2)<delay(SOC3)
delay(SOC0) delay(SOC1) delay(SOC2) delay(SOC3)
2       59      116     173
2       59      116     173
 
ADC3: All SOC in High Priority. SOC1,2 triggered by EPWM0SOCA.SOC0,3 triggered by EPWM0SOCB
Expected: delay(SOC1)<delay(SOC2) delay(SOC0)<delay(SOC3)
delay(SOC0) delay(SOC1) delay(SOC2) delay(SOC3)
2       2       59      59
2       2       59      59
 
ADC4: SOC0 in high Priority. All SOC triggered by EPWM0SOCA
Expected: delay(SOC0)<delay(SOC1)<delay(SOC2)<delay(SOC3)
delay(SOC0) delay(SOC1) delay(SOC2) delay(SOC3)
2       59      116     173
2       59      116     173
 
ADC4: SOC0 in round robin. SOC1,2 triggered by EPWM0SOCA.SOC0,3 triggered by EPWM0SOCB
Expected: delay(SOC0) should be between 0-1 conversions
    delay(SOC1) : 0 conversions, SOC2 : 2 Conversions, SOC3: 2 conversions
 
delay(SOC0) delay(SOC1) delay(SOC2) delay(SOC3)
2       2       59      59
2       2       59      59
 
ADC High Priority Test Passed!!
All tests have passed!!