Geofrey Marcel / FastPWM

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

Fork of FastPWM by Erik -

Device/FastPWM_LPC11U24.cpp@10:36362e9067b0, 2014-06-27 (annotated)

Committer:
Sissors
Date:
Fri Jun 27 06:18:23 2014 +0000
Revision:
10:36362e9067b0
Parent:
7:1b5df740bcd7
Child:
12:4600daab8a83
Same error as for the KLxx removed when multiple FastPWMs are used. Contrary to KLxx this gives a bit more overhead, but not much I can do about it while keeping the lib tidy

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Sissors 4:a7b9f778c4b4 1 #ifdef TARGET_LPC11U24
Sissors 4:a7b9f778c4b4 2
Sissors 4:a7b9f778c4b4 3 #include "FastPWM.h"
Sissors 4:a7b9f778c4b4 4
Sissors 4:a7b9f778c4b4 5 typedef struct {
Sissors 4:a7b9f778c4b4 6 uint8_t timer;
Sissors 4:a7b9f778c4b4 7 uint8_t mr;
Sissors 4:a7b9f778c4b4 8 } timer_mr;
Sissors 10:36362e9067b0 9
Sissors 10:36362e9067b0 10 LPC_CTxxBx_Type *pwm_obj;
Sissors 10:36362e9067b0 11 timer_mr tid;
Sissors 4:a7b9f778c4b4 12
Sissors 4:a7b9f778c4b4 13 static timer_mr pwm_timer_map[11] = {
Sissors 4:a7b9f778c4b4 14 {0, 0}, {0, 1}, {0, 2},
Sissors 4:a7b9f778c4b4 15 {1, 0}, {1, 1},
Sissors 4:a7b9f778c4b4 16 {2, 0}, {2, 1}, {2, 2},
Sissors 4:a7b9f778c4b4 17 {3, 0}, {3, 1}, {3, 2},
Sissors 4:a7b9f778c4b4 18 };
Sissors 4:a7b9f778c4b4 19
Sissors 4:a7b9f778c4b4 20 static LPC_CTxxBx_Type *Timers[4] = {
Sissors 4:a7b9f778c4b4 21 LPC_CT16B0, LPC_CT16B1,
Sissors 4:a7b9f778c4b4 22 LPC_CT32B0, LPC_CT32B1
Sissors 4:a7b9f778c4b4 23 };
Sissors 4:a7b9f778c4b4 24
Sissors 4:a7b9f778c4b4 25
Sissors 4:a7b9f778c4b4 26 void FastPWM::initFastPWM( void ) {
Sissors 10:36362e9067b0 27 tid = pwm_timer_map[_pwm.pwm];
Sissors 4:a7b9f778c4b4 28 pwm_obj = Timers[tid.timer];
Sissors 4:a7b9f778c4b4 29
Sissors 4:a7b9f778c4b4 30 if (tid.timer < 2)
Sissors 4:a7b9f778c4b4 31 //16-bit timer
Sissors 4:a7b9f778c4b4 32 bits = 16;
Sissors 4:a7b9f778c4b4 33 else
Sissors 4:a7b9f778c4b4 34 //32-bit timer
Sissors 7:1b5df740bcd7 35 bits = 32;
Sissors 4:a7b9f778c4b4 36 }
Sissors 4:a7b9f778c4b4 37
Sissors 4:a7b9f778c4b4 38 void FastPWM::pulsewidth_ticks( uint32_t ticks ) {
Sissors 10:36362e9067b0 39 tid = pwm_timer_map[_pwm.pwm];
Sissors 10:36362e9067b0 40 pwm_obj = Timers[tid.timer];
Sissors 10:36362e9067b0 41
Sissors 7:1b5df740bcd7 42 if (ticks)
Sissors 10:36362e9067b0 43 pwm_obj->MR[tid.mr] = pwm_obj->MR3 - ticks; //They inverted PWM on the 11u24
Sissors 7:1b5df740bcd7 44 else
Sissors 10:36362e9067b0 45 pwm_obj->MR[tid.mr] = 0xFFFFFFFF; //If MR3 = ticks 1 clock cycle wide errors appear, this prevents that (unless MR3 = max).
Sissors 4:a7b9f778c4b4 46 }
Sissors 4:a7b9f778c4b4 47
Sissors 4:a7b9f778c4b4 48 void FastPWM::period_ticks( uint32_t ticks ) {
Sissors 10:36362e9067b0 49 tid = pwm_timer_map[_pwm.pwm];
Sissors 10:36362e9067b0 50 pwm_obj = Timers[tid.timer];
Sissors 10:36362e9067b0 51
Sissors 4:a7b9f778c4b4 52 pwm_obj->TCR = 0x02;
Sissors 4:a7b9f778c4b4 53 pwm_obj->MR3 = ticks;
Sissors 4:a7b9f778c4b4 54 pwm_obj->TCR = 0x01;
Sissors 4:a7b9f778c4b4 55 }
Sissors 4:a7b9f778c4b4 56
Sissors 4:a7b9f778c4b4 57 uint32_t FastPWM::getPeriod( void ) {
Sissors 10:36362e9067b0 58 tid = pwm_timer_map[_pwm.pwm];
Sissors 10:36362e9067b0 59 pwm_obj = Timers[tid.timer];
Sissors 10:36362e9067b0 60
Sissors 4:a7b9f778c4b4 61 return pwm_obj->MR3;
Sissors 4:a7b9f778c4b4 62 }
Sissors 4:a7b9f778c4b4 63
Sissors 4:a7b9f778c4b4 64 uint32_t FastPWM::setPrescaler(uint32_t reqScale) {
Sissors 10:36362e9067b0 65 tid = pwm_timer_map[_pwm.pwm];
Sissors 10:36362e9067b0 66 pwm_obj = Timers[tid.timer];
Sissors 10:36362e9067b0 67
Sissors 4:a7b9f778c4b4 68 //If 32-bit, disable auto-scaling, return 1
Sissors 4:a7b9f778c4b4 69 if (bits == 32) {
Sissors 4:a7b9f778c4b4 70 dynamicPrescaler = false;
Sissors 4:a7b9f778c4b4 71 return 1;
Sissors 4:a7b9f778c4b4 72 }
Sissors 4:a7b9f778c4b4 73
Sissors 4:a7b9f778c4b4 74 //Else 16-bit timer:
Sissors 4:a7b9f778c4b4 75 if (reqScale == 0)
Sissors 4:a7b9f778c4b4 76 //Return prescaler
Sissors 4:a7b9f778c4b4 77 return pwm_obj->PR + 1;
Sissors 4:a7b9f778c4b4 78 if (reqScale > (uint32_t)(1<<16))
Sissors 4:a7b9f778c4b4 79 reqScale = 1<<16;
Sissors 4:a7b9f778c4b4 80 //Else set prescaler, we have to substract one from reqScale since a 0 in PCVAL is prescaler of 1
Sissors 4:a7b9f778c4b4 81 pwm_obj->PR = reqScale - 1;
Sissors 4:a7b9f778c4b4 82
Sissors 4:a7b9f778c4b4 83 return reqScale;
Sissors 4:a7b9f778c4b4 84 }
Sissors 4:a7b9f778c4b4 85
Sissors 4:a7b9f778c4b4 86 #endif