Diff: Device/FastPWM_LPC11U24.cpp

Revision:

4:a7b9f778c4b4

Child:

7:1b5df740bcd7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Device/FastPWM_LPC11U24.cpp	Tue Aug 13 16:54:06 2013 +0000
@@ -0,0 +1,80 @@
+#ifdef TARGET_LPC11U24
+
+#include "FastPWM.h"
+
+
+volatile uint32_t *PWM_MR;
+LPC_CTxxBx_Type *pwm_obj;
+
+typedef struct {
+    uint8_t timer;
+    uint8_t mr;
+} timer_mr;
+ 
+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
+};
+
+
+void FastPWM::initFastPWM( void ) {
+    //Sadly the 11u24 pwm object does not store match register/pwm object for some reason
+    //It recalculates it everytime, we just do it once because we are awesome
+    timer_mr tid = pwm_timer_map[_pwm.pwm];
+    pwm_obj = Timers[tid.timer];
+    PWM_MR = &pwm_obj->MR[tid.mr];
+    
+    if (tid.timer < 2)
+        //16-bit timer
+        bits = 16;
+    else
+        //32-bit timer
+        bits = 32;
+    
+    printf("Bits = %d, PWM = %d, MR = %d\n\r", bits, tid.timer, tid.mr);
+    
+}
+
+void FastPWM::pulsewidth_ticks( uint32_t ticks ) {
+    pwm_obj->TCR = 0x02;
+    *PWM_MR = pwm_obj->MR3 - ticks;  //They inverted PWM on the 11u24
+    pwm_obj->TCR = 0x01; 
+}
+
+void FastPWM::period_ticks( uint32_t ticks ) {
+    pwm_obj->TCR = 0x02;
+    pwm_obj->MR3 = ticks;
+    pwm_obj->TCR = 0x01;   
+}
+
+uint32_t FastPWM::getPeriod( void ) {
+    return pwm_obj->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_obj->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_obj->PR = reqScale - 1;
+
+    return reqScale;
+}
+
+#endif
\ No newline at end of file