SPRAD12A July   2022  – February 2023 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1 , TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1 , TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1 , TMS320F28075 , TMS320F28075-Q1 , TMS320F28076 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-EP , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S , TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S , TMS320F28P550SJ , TMS320F28P559SJ-Q1 , TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DK-Q1

 

  1.   Abstract
  2.   Trademarks
  3. 1 Introduction
  4. 2 SysConfig
  5. 3 Time-Base (TB) Submodule
    1. 3.1 Setting the Frequency
    2. 3.2 Applying a Phase Shift
    3. 3.3 Setting up the Synchronization (Sync) Scheme
  6. 4 Counter-Compare (CC) and Action-Qualifier (AQ) Submodules
    1. 4.1 Calculating the Duty Cycle
  7. 5 Deadband (DB) Submodule
    1. 5.1 Setting up Signal Pairs
  8. 6 Verifying the Output
    1. 6.1 Checking the Duty Cycle and Dead-Time Insertion
    2. 6.2 Checking the Phase Shift Applied
  9. 7 Trip-Zone (TZ) and Digital Compare (DC) Submodules
    1. 7.1 Drive Outputs Low for an ePWM Cycle Upon Trip Condition Set Through CMPSS
    2. 7.2 Drive Outputs Low Until Cleared Through Software Upon Trip Condition set Through GPIO
  10. 8 Event-Trigger (ET) Submodule
    1. 8.1 Setting Up Time-Base Interrupts
  11. 9 Global Load
    1. 9.1 Applying Global Loading and One-Shot Load Feature
    2. 9.2 Linking the ePWM Modules
    3. 9.3 Updating Action Qualifier Settings and Counter Compare Values Through Global Loading
  12. 10Summary
  13. 11References
  14. 12Revision History

9.3 Updating Action Qualifier Settings and Counter Compare Values Through Global Loading

Now that global loading and linking have been set up, the next step is writing the application code to modify the action qualifier settings and counter compare values. For this application report, the counter compare values are changed from 69 to 100 and the action qualifier settings are reversed. For ePWMxA, the settings are now cleared on CMPA up and set on CMPA down. The following code shows these new settings as well as the global load one-shot latch being set after the settings are updated. The code should normally be integrated into a control loop that is asynchronous to the ePWM cycle. However, to more clearly display functionality, it is placed within the main for-loop of this application report's program. To enable the new settings, set the variable “perform_one_shot_load” to one through the expression window of CCS.


if(perform_one_shot_load==1)
  {  
    //
    // EPWM1, EPWM2, EPWM3 are linked so only EPWM1 needs to be updated
    //
    EPWM_setCounterCompareValue(myEPWM1_BASE, EPWM_COUNTER_COMPARE_A, 100);
    EPWM_setCounterCompareValue(myEPWM1_BASE, EPWM_COUNTER_COMPARE_B, 100);
    //
    // Change the Action Qualifier Settings for EPWM1, EPWM2, and EPWM3
    //
    EPWM_setActionQualifierAction(myEPWM1_BASE,EPWM_AQ_OUTPUT_A,EPWM_AQ_OUTPUT_LOW,
                                            EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);
    EPWM_setActionQualifierAction(myEPWM1_BASE,EPWM_AQ_OUTPUT_A,EPWM_AQ_OUTPUT_HIGH,
                                            EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA);
    EPWM_setActionQualifierAction(myEPWM2_BASE,EPWM_AQ_OUTPUT_A,EPWM_AQ_OUTPUT_LOW,
                                            EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);
    EPWM_setActionQualifierAction(myEPWM2_BASE,EPWM_AQ_OUTPUT_A,EPWM_AQ_OUTPUT_HIGH,
                                            EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA);    
    EPWM_setActionQualifierAction(myEPWM3_BASE,EPWM_AQ_OUTPUT_A,EPWM_AQ_OUTPUT_LOW,
                                            EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);
    EPWM_setActionQualifierAction(myEPWM3_BASE,EPWM_AQ_OUTPUT_A,EPWM_AQ_OUTPUT_HIGH,
                                            EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA);
    //
    // EPWM1, EPWM2, EPWM3 are linked
    //
    EPWM_setGlobalLoadOneShotLatch(myEPWM1_BASE);
    //
    // Clear the setting
    //
    perform_one_shot_load = 0;
}
Note: Remember to declare 'perform_one_shot_load' as part of the global variables of the program.
Note: For projects utilizing C2000Ware version 4.01 or below, the following workaround is required to ensure the action qualifier settings are not cleared after enabling the global loading feature within SysConfig. Insert the code below within the main function after the 'board_init()' function call.
      
EPWM_setActionQualifierAction(myEPWM1_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);
EPWM_setActionQualifierAction(myEPWM1_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA);
EPWM_setActionQualifierAction(myEPWM1_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPB);
EPWM_setActionQualifierAction(myEPWM1_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPB);

EPWM_setActionQualifierAction(myEPWM2_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);
EPWM_setActionQualifierAction(myEPWM2_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA);
EPWM_setActionQualifierAction(myEPWM2_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPB);
EPWM_setActionQualifierAction(myEPWM2_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPB);

EPWM_setActionQualifierAction(myEPWM3_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);
EPWM_setActionQualifierAction(myEPWM3_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA);
EPWM_setActionQualifierAction(myEPWM3_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPB);
EPWM_setActionQualifierAction(myEPWM3_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPB);
     
// EPWM1, EPWM2, EPWM3 are linked so this will update both
EPWM_setGlobalLoadOneShotLatch(myEPWM1_BASE);

Redoing the calculations from earlier, the new duty cycle should be as shown in Equation 24:

Equation 24. Duty Cycle= CMPA+(CMPA-DBRED)TBPRD*2= 100+80250= 180250=72 %

Putting it in terms of time, 180 * 10 nsec is 1.8 µsec, so the positive pulse width should be 1.8 µsec as seen in #GUID-2E7255E7-1D44-4C5F-95B5-040A3C8676D6.

Figure 9-2 Scope Capture of ePWM Output Positive Duty After AQ and CC Updates