TweinStein/RTOS_Labs_common/PWMG6.c

/* PWMG6.c
 * Jonathan Valvano
 * November 24, 2025
 * Derived from timx_timer_mode_pwm_edge_sleep_LP_MSPM0G3507_nortos_ticlang
 
 */

/*
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 */

#include <ti/devices/msp/msp.h>
#include "../inc/LaunchPad.h"
#include "../RTOS_Labs_common/PWMG6.h"
#include "../inc/Clock.h"
//  Timer G6  is on Power domain PD1
// for 32MHz bus clock, Timer clock is 32MHz
// for 40MHz bus clock, Timer clock is MCLK 40MHz
// for 80MHz bus clock, Timer clock is MCLK 80MHz
// CCP0 PWM output on PB6
// PB6/TIMG6_C0;

uint32_t PWMG6_Period;
// Initialize PWM output on PB6
// Rising edge synchronized
// timerClkSrc = 2 for 32768 Hz LFCLK
//             = 4 for 4MHz MFCLK
//             = 8 for 80/40/32/4 BUSCLK
// divide clock by timerClkPrescale+1, 0 to 255
// period sets the PWM period
// timerClkSrc could be 40MHz, 32MHz, 4MHz, or 32767Hz
// timerClkDivRatio = 1
// PWMFreq = (timerClkSrc / (timerClkDivRatio * (timerClkPrescale + 1) * period))
// For example, source=LFCLK, prescale=0, period = 1000, PWM frequency = 32.768 Hz
// For example, source=BUSCLK, 80MHz bus, prescale=39, period = 10000, PWM frequency = 200Hz
void PWMG6_Init(uint32_t timerClkSrc, uint32_t timerClkPrescale, uint32_t period, uint32_t duty){
  TIMG6->GPRCM.RSTCTL = (uint32_t)0xB1000003;
  TIMG6->GPRCM.PWREN = (uint32_t)0x26000001;
  Clock_Delay(2); // time for TimerG6 to power up
  IOMUX->SECCFG.PINCM[PB6INDEX]  = 0x00000087; // TIMG6 output CCP0
  GPIOB->DOE31_0 |= (1<<6);
  TIMG6->CLKSEL = timerClkSrc; // 8=BUSCLK, 4= MFCLK, 2= LFCLK clock
  TIMG6->CLKDIV = 0x00; // divide by 1
  TIMG6->COMMONREGS.CPS = timerClkPrescale;     // divide by prescale+1,
  // 32768Hz/256 = 256Hz, 7.8125
  TIMG6->COUNTERREGS.LOAD  = period-1;  // reload register sets period
  PWMG6_Period = period;
  TIMG6->COUNTERREGS.CTRCTL = 0x02;
  // bits 5-4 CM =0, down
  // bits 3-1 REPEAT =001, continue
  // bit 0 EN enable (0 for disable, 1 for enable)
  TIMG6->COUNTERREGS.CCCTL_01[0] = 0; // no capture
   // COC compare mode
  TIMG6->GEN_EVENT0.IMASK = 0x00; // no interrupts
  TIMG6->COMMONREGS.CCPD = 0x01;  // output CCP0
  TIMG6->COMMONREGS.CCLKCTL = 1;
  TIMG6->COUNTERREGS.CC_01[0] = PWMG6_Period-duty;
  TIMG6->COUNTERREGS.OCTL_01[0] = 0x0000; // connected to PWM
  TIMG6->COUNTERREGS.CCACT_01[0] = 0x0088;

  // bits 10-9 CUACT 0 for no action on up compare
  // bits 7-6 CDACT 10 for make low on compare event down
  // bits 4-3 LACT 01 for make high on load event
  // bits 1-0 ZACT 00 for no action on zero event
  TIMG6->COUNTERREGS.CTRCTL |= 0x01;
}

void PWMG6_SetDuty(uint32_t duty){
  TIMG6->COUNTERREGS.CC_01[0] = PWMG6_Period-duty;
}