Geofrey Marcel / FastPWM

Fork of Erik Olieman's FastPWM library created to add the targets I need.

Fork of FastPWM by Erik -

Device/FastPWM_KLXX_K20D50M.cpp@11:e0a8f0fcb1c9, 2014-07-16 (annotated)

Committer:
Sissors
Date:
Wed Jul 16 15:44:21 2014 +0000
Revision:
11:e0a8f0fcb1c9
Child:
14:b30038fbba51
K20D50M added

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Sissors 11:e0a8f0fcb1c9 1 #if defined(TARGET_KLXX) || defined(TARGET_K20D50M)
Sissors 11:e0a8f0fcb1c9 2
Sissors 11:e0a8f0fcb1c9 3 #include "FastPWM.h"
Sissors 11:e0a8f0fcb1c9 4
Sissors 11:e0a8f0fcb1c9 5 void FastPWM::initFastPWM( void ) {
Sissors 11:e0a8f0fcb1c9 6 bits = 16;
Sissors 11:e0a8f0fcb1c9 7 }
Sissors 11:e0a8f0fcb1c9 8
Sissors 11:e0a8f0fcb1c9 9 void FastPWM::pulsewidth_ticks( uint32_t ticks ) {
Sissors 11:e0a8f0fcb1c9 10 *(_pwm.CnV) = ticks;
Sissors 11:e0a8f0fcb1c9 11 }
Sissors 11:e0a8f0fcb1c9 12
Sissors 11:e0a8f0fcb1c9 13 void FastPWM::period_ticks( uint32_t ticks ) {
Sissors 11:e0a8f0fcb1c9 14 *(_pwm.MOD) = ticks - 1;
Sissors 11:e0a8f0fcb1c9 15 }
Sissors 11:e0a8f0fcb1c9 16
Sissors 11:e0a8f0fcb1c9 17 uint32_t FastPWM::getPeriod( void ) {
Sissors 11:e0a8f0fcb1c9 18 return *(_pwm.MOD) + 1;
Sissors 11:e0a8f0fcb1c9 19 }
Sissors 11:e0a8f0fcb1c9 20
Sissors 11:e0a8f0fcb1c9 21 uint32_t FastPWM::setPrescaler(uint32_t reqScale) {
Sissors 11:e0a8f0fcb1c9 22
Sissors 11:e0a8f0fcb1c9 23 //Yes this is ugly, yes I should feel bad about it
Sissors 11:e0a8f0fcb1c9 24 volatile uint32_t *TPM_SC = _pwm.MOD - 2;
Sissors 11:e0a8f0fcb1c9 25
Sissors 11:e0a8f0fcb1c9 26 const char prescalers[] = {1, 2, 4, 8, 16, 32, 64, 128};
Sissors 11:e0a8f0fcb1c9 27
Sissors 11:e0a8f0fcb1c9 28 //If prescaler is 0, return current one
Sissors 11:e0a8f0fcb1c9 29 if (reqScale == 0)
Sissors 11:e0a8f0fcb1c9 30 return (prescalers[(*TPM_SC) & 0x07]);
Sissors 11:e0a8f0fcb1c9 31
Sissors 11:e0a8f0fcb1c9 32 uint32_t retval = 0;
Sissors 11:e0a8f0fcb1c9 33 char bin;
Sissors 11:e0a8f0fcb1c9 34
Sissors 11:e0a8f0fcb1c9 35 for (bin = 0; bin<8; bin++) {
Sissors 11:e0a8f0fcb1c9 36 retval = prescalers[bin];
Sissors 11:e0a8f0fcb1c9 37 if (retval >= reqScale)
Sissors 11:e0a8f0fcb1c9 38 break;
Sissors 11:e0a8f0fcb1c9 39 }
Sissors 11:e0a8f0fcb1c9 40
Sissors 11:e0a8f0fcb1c9 41 //Clear lower 5 bits, write new value:
Sissors 11:e0a8f0fcb1c9 42 char clockbits = *TPM_SC & (3<<3);
Sissors 11:e0a8f0fcb1c9 43
Sissors 11:e0a8f0fcb1c9 44 //For some reason clearing them takes some effort
Sissors 11:e0a8f0fcb1c9 45 while ((*TPM_SC & 0x1F) != 0)
Sissors 11:e0a8f0fcb1c9 46 *TPM_SC &= ~0x1F;
Sissors 11:e0a8f0fcb1c9 47
Sissors 11:e0a8f0fcb1c9 48
Sissors 11:e0a8f0fcb1c9 49 *TPM_SC |= bin + clockbits;
Sissors 11:e0a8f0fcb1c9 50
Sissors 11:e0a8f0fcb1c9 51 return retval;
Sissors 11:e0a8f0fcb1c9 52 }
Sissors 11:e0a8f0fcb1c9 53 #endif