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Hi,
I need to know what will happen if my configuration of EPWM as mention below
INTSEL = 1 (Genrate interrupt on CTR=0);
CMPA Load Mode is shadow on CTR=0;
If I update CMPA value in ISR which value will be taken for compare previous or current? In other words first ISR will generate or CMPA value will get update?
Epwm1_ISR() // genrating on CTR=0
{
//CMPA loading here, so current will go to active register which I am loading here or previous one which was loaded in shadow register in last interrupt?
}
I think in this case it get delayed one period?
In control suite example of HVACI_Scalar, in this example they are using configuration like above I think in that case three phase sinusoidal PWM generation will get delayed by one period? I have mention example configuration below.
/*************************************************************************************************************/
// Enable CNT_zero interrupt using EPWM1 Time-base
EPwm1Regs.ETSEL.bit.INTEN = 1; // Enable EPWM1INT generation
EPwm1Regs.ETSEL.bit.INTSEL = 1; // Enable interrupt CNT_zero event
EPwm1Regs.ETPS.bit.INTPRD = 1; // Generate interrupt on the 1st event
EPwm1Regs.ETCLR.bit.INT = 1; // Enable more interrupts
EALLOW; // This is needed to write to EALLOW protected registers
PieVectTable.EPWM1_INT = &MainISR;
EDIS;
/*----------------------------------------------------------------------------
Initialization constant for the F2803X Compare Control Register.
----------------------------------------------------------------------------*/
#define CMPCTL_INIT_STATE ( LOADAMODE_ZRO + \
LOADBMODE_ZRO + \
SHDWAMODE_SHADOW + \
SHDWBMODE_SHADOW )
//MainISR
interrupt void MainISR(void)
{
// ------------------------------------------------------------------------------
// Connect inputs of the SVGEN_MF module and call the space-vector gen. macro
// ------------------------------------------------------------------------------
svgen_mf1.Gain = vhz1.VoltOut;
svgen_mf1.Freq = vhz1.Freq;
SVGENMF_MACRO(svgen_mf1);
// ------------------------------------------------------------------------------
// Connect inputs of the PWM_DRV module and call the PWM signal generation macro
// ------------------------------------------------------------------------------
pwm1.MfuncC1 = svgen_mf1.Ta;
pwm1.MfuncC2 = svgen_mf1.Tb;
pwm1.MfuncC3 = svgen_mf1.Tc;
PWM_MACRO(1,2,3,pwm1) // Calculate the new PWM compare values
}
Hi,
Thanks for the reply!
I have same doubt mention below and need more explanation.
In control suite example of HVACI_Scalar (ti\controlSUITE\development_kits\HVMotorCtrl+PfcKit_v2.1\HVACI_Scalar), in this example they are using configuration like which I asked in thread above (CMPA Loading and Generating ISR for CMPR update both on CTR -= 0) I think in that case three phase PWM generation will get delayed by one period (old sample value will compare)? I have mention example configuration below.
Please go through it and let me know in this example also pwm will be delayed or not by one period? If it is delayed then will it create any performance problem in rotating motor?
/*************************************************************************************************************/
// Enable CNT_zero interrupt using EPWM1 Time-base
EPwm1Regs.ETSEL.bit.INTEN = 1; // Enable EPWM1INT generation
EPwm1Regs.ETSEL.bit.INTSEL = 1; // Enable interrupt CNT_zero event
EPwm1Regs.ETPS.bit.INTPRD = 1; // Generate interrupt on the 1st event
EPwm1Regs.ETCLR.bit.INT = 1; // Enable more interrupts
EALLOW; // This is needed to write to EALLOW protected registers
PieVectTable.EPWM1_INT = &MainISR;
EDIS;
/*----------------------------------------------------------------------------
Initialization constant for the F2803X Compare Control Register.
----------------------------------------------------------------------------*/
#define CMPCTL_INIT_STATE ( LOADAMODE_ZRO + \
LOADBMODE_ZRO + \
SHDWAMODE_SHADOW + \
SHDWBMODE_SHADOW )
//MainISR
interrupt void MainISR(void)
{
// ------------------------------------------------------------------------------
// Connect inputs of the SVGEN_MF module and call the space-vector gen. macro
// ------------------------------------------------------------------------------
svgen_mf1.Gain = vhz1.VoltOut;
svgen_mf1.Freq = vhz1.Freq;
SVGENMF_MACRO(svgen_mf1);
// ------------------------------------------------------------------------------
// Connect inputs of the PWM_DRV module and call the PWM signal generation macro
// ------------------------------------------------------------------------------
pwm1.MfuncC1 = svgen_mf1.Ta;
pwm1.MfuncC2 = svgen_mf1.Tb;
pwm1.MfuncC3 = svgen_mf1.Tc;
PWM_MACRO(1,2,3,pwm1) // Calculate the new PWM compare values
}
