Specifications

ManualsBrandsPulse ManualsFitness Equipment280

www.ti.com

Operational Description of HRPWM

The example code shown consists of two main parts:

• Initialization code (executed once)

• Run time code (typically executed within an ISR)

Example 6 shows the Initialization code. The first part is configured for conventional PWM. The second

part sets up the HRPWM resources.

This example assumes MEP step size of 150 ps and does not use the SFO library.

Example 6. HRPWM Buck Converter Initialization Code

void HrBuckDrvCnf(void)

{

// Config for conventional PWM first

EPwm1Regs.TBCTL.bit.PRDLD = TB_IMMEDIATE; // set Immediate load

EPwm1Regs.TBPRD = 100; // Period set for 1000 kHz PWM

hrbuck_period = 200; // Used for Q15 to Q0 scaling

EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP;

EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE; // EPWM1 is the Master

EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_DISABLE;

EPwm1Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1;

EPwm1Regs.TBCTL.bit.CLKDIV = TB_DIV1;

// Note: ChB is initialized here only for comparison purposes, it is not required

EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;

EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;

EPwm1Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO; // optional

EPwm1Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW; // optional

EPwm1Regs.AQCTLA.bit.ZRO = AQ_SET;

EPwm1Regs.AQCTLA.bit.CAU = AQ_CLEAR;

EPwm1Regs.AQCTLB.bit.ZRO = AQ_SET; // optional

EPwm1Regs.AQCTLB.bit.CBU = AQ_CLEAR; // optional

// Now configure the HRPWM resources

EALLOW; // Note these registers are protected

// and act only on ChA

EPwm1Regs.HRCNFG.all = 0x0; // clear all bits first

EPwm1Regs.HRCNFG.bit.EDGMODE = HR_FEP; // Control Falling Edge Position

EPwm1Regs.HRCNFG.bit.CTLMODE = HR_CMP; // CMPAHR controls the MEP

EPwm1Regs.HRCNFG.bit.HRLOAD = HR_CTR_ZERO; // Shadow load on CTR=Zero

EDIS;

MEP_ScaleFactor = 66*256; // Start with typical Scale Factor

// value for 100 MHz

// Note: Use SFO functions to update

// MEP_ScaleFactor dynamically

}

Example 7 shows an assembly example of run-time code for the HRPWM buck converter.

Example 7. HRPWM Buck Converter Run-Time Code

EPWM1_BASE .set 0x6800

CMPAHR1 .set EPWM1_BASE+0x8

;===============================================

HRBUCK_DRV; (can execute within an ISR or loop)

;===============================================

MOVW DP, #_HRBUCK_In

MOVL XAR2,@_HRBUCK_In ; Pointer to Input Q15 Duty (XAR2)

MOVL XAR3,#CMPAHR1 ; Pointer to HRPWM CMPA reg (XAR3)

; Output for EPWM1A (HRPWM)

MOV T,*XAR2 ; T <= Duty

SPRU924F– April 2005– Revised October 2011 High-Resolution Pulse Width Modulator (HRPWM)

Submit Documentation Feedback