Alp Sayin / FastPWM

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Fork of FastPWM by Erik -

Device/FastPWM_KLXX.cpp@9:c50f688cad07, 2014-06-27 (annotated)

Committer:
Sissors
Date:
Fri Jun 27 06:02:37 2014 +0000
Revision:
9:c50f688cad07
Parent:
8:a7745c791b0c 
Period of KLxx decreased by 1 before writing to make sure it is exactly correct for my beloved users.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Sissors 5:2812f0a115f7 1 #ifdef TARGET_KLXX
Sissors 4:a7b9f778c4b4 2
Sissors 4:a7b9f778c4b4 3 #include "FastPWM.h"
Sissors 4:a7b9f778c4b4 4
Sissors 4:a7b9f778c4b4 5 void FastPWM::initFastPWM( void ) {
Sissors 4:a7b9f778c4b4 6 bits = 16;
Sissors 4:a7b9f778c4b4 7 }
Sissors 4:a7b9f778c4b4 8
Sissors 4:a7b9f778c4b4 9 void FastPWM::pulsewidth_ticks( uint32_t ticks ) {
Sissors 4:a7b9f778c4b4 10 *(_pwm.CnV) = ticks;
Sissors 4:a7b9f778c4b4 11 }
Sissors 4:a7b9f778c4b4 12
Sissors 4:a7b9f778c4b4 13 void FastPWM::period_ticks( uint32_t ticks ) {
Sissors 9:c50f688cad07 14 *(_pwm.MOD) = ticks - 1;
Sissors 4:a7b9f778c4b4 15 }
Sissors 4:a7b9f778c4b4 16
Sissors 4:a7b9f778c4b4 17 uint32_t FastPWM::getPeriod( void ) {
Sissors 9:c50f688cad07 18 return *(_pwm.MOD) + 1;
Sissors 4:a7b9f778c4b4 19 }
Sissors 4:a7b9f778c4b4 20
Sissors 4:a7b9f778c4b4 21 uint32_t FastPWM::setPrescaler(uint32_t reqScale) {
Sissors 8:a7745c791b0c 22
Sissors 8:a7745c791b0c 23 //Yes this is ugly, yes I should feel bad about it
Sissors 8:a7745c791b0c 24 volatile uint32_t *TPM_SC = _pwm.MOD - 2;
Sissors 8:a7745c791b0c 25
Sissors 4:a7b9f778c4b4 26 const char prescalers[] = {1, 2, 4, 8, 16, 32, 64, 128};
Sissors 4:a7b9f778c4b4 27
Sissors 4:a7b9f778c4b4 28 //If prescaler is 0, return current one
Sissors 4:a7b9f778c4b4 29 if (reqScale == 0)
Sissors 4:a7b9f778c4b4 30 return (prescalers[(*TPM_SC) & 0x07]);
Sissors 4:a7b9f778c4b4 31
Sissors 4:a7b9f778c4b4 32 uint32_t retval = 0;
Sissors 4:a7b9f778c4b4 33 char bin;
Sissors 4:a7b9f778c4b4 34
Sissors 4:a7b9f778c4b4 35 for (bin = 0; bin<8; bin++) {
Sissors 4:a7b9f778c4b4 36 retval = prescalers[bin];
Sissors 4:a7b9f778c4b4 37 if (retval >= reqScale)
Sissors 4:a7b9f778c4b4 38 break;
Sissors 4:a7b9f778c4b4 39 }
Sissors 4:a7b9f778c4b4 40
Sissors 4:a7b9f778c4b4 41 //Clear lower 5 bits, write new value:
Sissors 4:a7b9f778c4b4 42 char clockbits = *TPM_SC & (3<<3);
Sissors 4:a7b9f778c4b4 43
Sissors 4:a7b9f778c4b4 44 //For some reason clearing them takes some effort
Sissors 4:a7b9f778c4b4 45 while ((*TPM_SC & 0x1F) != 0)
Sissors 4:a7b9f778c4b4 46 *TPM_SC &= ~0x1F;
Sissors 4:a7b9f778c4b4 47
Sissors 4:a7b9f778c4b4 48
Sissors 4:a7b9f778c4b4 49 *TPM_SC |= bin + clockbits;
Sissors 4:a7b9f778c4b4 50
Sissors 4:a7b9f778c4b4 51 return retval;
Sissors 4:a7b9f778c4b4 52 }
Sissors 4:a7b9f778c4b4 53 #endif