Diff: Device/FastPWM_LPC11XX.cpp

Revision:

23:ed690a19dc55

Parent:

12:4600daab8a83

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Device/FastPWM_LPC11XX.cpp	Sun Apr 19 19:35:50 2015 +0000
@@ -0,0 +1,103 @@
+#if defined(TARGET_LPC11UXX) || defined(TARGET_LPC11XX_11CXX)
+
+#include "FastPWM.h"
+
+#define PWM_MR              (*(((fastpwm_struct*)fast_obj)->MR))   
+#define PWM_TIMER           (((fastpwm_struct*)fast_obj)->timer)      
+
+typedef struct {
+    uint8_t timer;
+    uint8_t mr;
+} timer_mr;
+ 
+#ifdef TARGET_LPC11UXX
+typedef struct  {
+    __IO uint32_t *MR;
+    LPC_CTxxBx_Type *timer;
+} fastpwm_struct;
+
+static timer_mr pwm_timer_map[11] = {
+    {0, 0}, {0, 1}, {0, 2},
+    {1, 0}, {1, 1},
+    {2, 0}, {2, 1}, {2, 2},
+    {3, 0}, {3, 1}, {3, 2},
+};
+
+static LPC_CTxxBx_Type *Timers[4] = {
+    LPC_CT16B0, LPC_CT16B1,
+    LPC_CT32B0, LPC_CT32B1
+};
+#else           //LPC11XX
+typedef struct  {
+    __IO uint32_t *MR;
+    LPC_TMR_TypeDef *timer;
+} fastpwm_struct;
+
+static timer_mr pwm_timer_map[5] = {
+    {0, 0}, /* CT16B0, MR0 */
+    {0, 1}, /* CT16B0, MR1 */
+ 
+    {1, 0}, /* CT16B1, MR0 */
+    {1, 1}, /* CT16B1, MR1 */
+ 
+    {2, 2}, /* CT32B0, MR2 */
+};
+
+static LPC_TMR_TypeDef *Timers[3] = {
+    LPC_TMR16B0, LPC_TMR16B1,
+    LPC_TMR32B0
+};
+#endif
+
+
+void FastPWM::initFastPWM( void ) {
+    fast_obj = new fastpwm_struct;
+    timer_mr tid = pwm_timer_map[_pwm.pwm];
+    PWM_TIMER = Timers[tid.timer];
+    (((fastpwm_struct*)fast_obj)->MR) = &PWM_TIMER->MR[tid.mr];
+    
+    if (tid.timer < 2)
+        //16-bit timer
+        bits = 16;
+    else
+        //32-bit timer
+        bits = 32;  
+}
+
+void FastPWM::pulsewidth_ticks( uint32_t ticks ) {
+    if (ticks)
+        PWM_MR = PWM_TIMER->MR3 - ticks;  //They inverted PWM on the 11u24
+    else
+        PWM_MR = 0xFFFFFFFF;           //If MR3 = ticks 1 clock cycle wide errors appear, this prevents that (unless MR3 = max).
+}
+
+void FastPWM::period_ticks( uint32_t ticks ) {  
+    PWM_TIMER->TCR = 0x02;
+    PWM_TIMER->MR3 = ticks;
+    PWM_TIMER->TCR = 0x01;   
+}
+
+uint32_t FastPWM::getPeriod( void ) {
+    return PWM_TIMER->MR3;
+}
+
+uint32_t FastPWM::setPrescaler(uint32_t reqScale) {
+    //If 32-bit, disable auto-scaling, return 1
+    if (bits == 32) {
+        dynamicPrescaler = false;
+        return 1;
+    }
+    
+    //Else 16-bit timer:
+    if (reqScale == 0)
+        //Return prescaler
+        return PWM_TIMER->PR + 1;
+    if (reqScale > (uint32_t)(1<<16))
+        reqScale = 1<<16;
+    //Else set prescaler, we have to substract one from reqScale since a 0 in PCVAL is prescaler of 1
+    PWM_TIMER->PR = reqScale - 1;
+
+    return reqScale;
+}
+
+#endif
\ No newline at end of file