cebri alyac / FastPWM

yes

Device/FastPWM_KSDK.cpp@0:c60399891edd, 2022-05-08 (annotated)

Committer:
braichi13
Date:
Sun May 08 14:39:57 2022 +0000
Revision:
0:c60399891edd
Yes

Who changed what in which revision?

UserRevisionLine numberNew contents of line
braichi13 0:c60399891edd 1 #if defined(TARGET_KPSDK_MCUS)
braichi13 0:c60399891edd 2
braichi13 0:c60399891edd 3 #include "FastPWM.h"
braichi13 0:c60399891edd 4 #include "fsl_ftm.h"
braichi13 0:c60399891edd 5
braichi13 0:c60399891edd 6
braichi13 0:c60399891edd 7 #define PWM_CNV (*(((fastpwm_struct*)fast_obj)->CnV))
braichi13 0:c60399891edd 8 #define PWM_MOD (*(((fastpwm_struct*)fast_obj)->MOD))
braichi13 0:c60399891edd 9 #define PWM_SC (*(((fastpwm_struct*)fast_obj)->SC))
braichi13 0:c60399891edd 10 #define PWM_SYNC (*(((fastpwm_struct*)fast_obj)->SYNC))
braichi13 0:c60399891edd 11
braichi13 0:c60399891edd 12 typedef struct {
braichi13 0:c60399891edd 13 __IO uint32_t *CnV;
braichi13 0:c60399891edd 14 __IO uint32_t *MOD;
braichi13 0:c60399891edd 15 __IO uint32_t *SC;
braichi13 0:c60399891edd 16 __IO uint32_t *SYNC;
braichi13 0:c60399891edd 17 } fastpwm_struct;
braichi13 0:c60399891edd 18
braichi13 0:c60399891edd 19 static uint32_t pwm_prescaler;
braichi13 0:c60399891edd 20 static FTM_Type *const ftm_addrs[] = FTM_BASE_PTRS;
braichi13 0:c60399891edd 21
braichi13 0:c60399891edd 22 void FastPWM::initFastPWM( void ) {
braichi13 0:c60399891edd 23 fast_obj = new fastpwm_struct;
braichi13 0:c60399891edd 24 bits = 16;
braichi13 0:c60399891edd 25
braichi13 0:c60399891edd 26 pwm_prescaler = SystemCoreClock / CLOCK_GetFreq(kCLOCK_BusClk);;
braichi13 0:c60399891edd 27
braichi13 0:c60399891edd 28 unsigned int ch_n = (_pwm.pwm_name & 0xF);
braichi13 0:c60399891edd 29 FTM_Type *ftm = ftm_addrs[_pwm.pwm_name >> TPM_SHIFT];
braichi13 0:c60399891edd 30
braichi13 0:c60399891edd 31 ((fastpwm_struct*)fast_obj)->CnV = &ftm->CONTROLS[ch_n].CnV;
braichi13 0:c60399891edd 32 ((fastpwm_struct*)fast_obj)->MOD = &ftm->MOD;
braichi13 0:c60399891edd 33 ((fastpwm_struct*)fast_obj)->SC = &ftm->SC;
braichi13 0:c60399891edd 34 ((fastpwm_struct*)fast_obj)->SYNC = &ftm->SYNC;
braichi13 0:c60399891edd 35
braichi13 0:c60399891edd 36 //Do not clear counter when writing new value, set end of period as loading value
braichi13 0:c60399891edd 37 ftm->SYNCONF &= ~FTM_SYNCONF_SWRSTCNT_MASK;
braichi13 0:c60399891edd 38 ftm->SYNC |= FTM_SYNC_CNTMAX_MASK;
braichi13 0:c60399891edd 39 }
braichi13 0:c60399891edd 40
braichi13 0:c60399891edd 41 void FastPWM::pulsewidth_ticks( uint32_t ticks ) {
braichi13 0:c60399891edd 42 PWM_CNV = ticks;
braichi13 0:c60399891edd 43 PWM_SYNC |= FTM_SYNC_SWSYNC_MASK;
braichi13 0:c60399891edd 44 }
braichi13 0:c60399891edd 45
braichi13 0:c60399891edd 46 void FastPWM::period_ticks( uint32_t ticks ) {
braichi13 0:c60399891edd 47 PWM_MOD = ticks - 1;
braichi13 0:c60399891edd 48 PWM_SYNC |= FTM_SYNC_SWSYNC_MASK;
braichi13 0:c60399891edd 49 }
braichi13 0:c60399891edd 50
braichi13 0:c60399891edd 51 uint32_t FastPWM::getPeriod( void ) {
braichi13 0:c60399891edd 52 return PWM_MOD + 1;
braichi13 0:c60399891edd 53 }
braichi13 0:c60399891edd 54
braichi13 0:c60399891edd 55 uint32_t FastPWM::setPrescaler(uint32_t reqScale) {
braichi13 0:c60399891edd 56
braichi13 0:c60399891edd 57 uint32_t prescalers[] = {1, 2, 4, 8, 16, 32, 64, 128};
braichi13 0:c60399891edd 58
braichi13 0:c60399891edd 59 for (int i = 0; i<8; i++)
braichi13 0:c60399891edd 60 prescalers[i] = prescalers[i] * pwm_prescaler;
braichi13 0:c60399891edd 61
braichi13 0:c60399891edd 62 //If prescaler is 0, return current one
braichi13 0:c60399891edd 63 if (reqScale == 0)
braichi13 0:c60399891edd 64 return (prescalers[(PWM_SC) & 0x07]);
braichi13 0:c60399891edd 65
braichi13 0:c60399891edd 66 uint32_t retval = 0;
braichi13 0:c60399891edd 67 char bin;
braichi13 0:c60399891edd 68
braichi13 0:c60399891edd 69 for (bin = 0; bin<8; bin++) {
braichi13 0:c60399891edd 70 retval = prescalers[bin];
braichi13 0:c60399891edd 71 if (retval >= reqScale)
braichi13 0:c60399891edd 72 break;
braichi13 0:c60399891edd 73 }
braichi13 0:c60399891edd 74 if (bin == 8)
braichi13 0:c60399891edd 75 bin = 7;
braichi13 0:c60399891edd 76
braichi13 0:c60399891edd 77 //Clear lower 5 bits, write new value:
braichi13 0:c60399891edd 78 char clockbits = PWM_SC & (3<<3);
braichi13 0:c60399891edd 79
braichi13 0:c60399891edd 80 //For some reason clearing them takes some effort
braichi13 0:c60399891edd 81 while ((PWM_SC & 0x1F) != 0)
braichi13 0:c60399891edd 82 PWM_SC &= ~0x1F;
braichi13 0:c60399891edd 83
braichi13 0:c60399891edd 84
braichi13 0:c60399891edd 85 PWM_SC = bin + clockbits;
braichi13 0:c60399891edd 86 return retval;
braichi13 0:c60399891edd 87 }
braichi13 0:c60399891edd 88 #endif