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Fix default polarity on LPC43XX PWM driver

pull/3290/head
micromint 2016-11-10 13:00:34 -04:00 committed by Anna Bridge
parent 9d7dbcdcd6
commit 99631dabb3
1 changed files with 11 additions and 6 deletions
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17
targets/TARGET_NXP/TARGET_LPC43XX/pwmout_api.c
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@ -29,7 +29,9 @@
// configuration options // configuration options
#define PWM_FREQ_BASE 1000000 // Base frequency 1 MHz = 1000000 #define PWM_FREQ_BASE 1000000 // Base frequency 1 MHz = 1000000
#define PWM_MODE 1 // 0 = 32-bit, 1 = 16-bit low, 2 = 16-bit high #ifndef PWM_MODE
#define PWM_MODE 1 // 0 = 32-bit, 1 = 16-bit low, 2 = 16-bit high
#endif
// macros // macros
#define PWM_SETCOUNT(x) (x - 1) // set count value #define PWM_SETCOUNT(x) (x - 1) // set count value
@ -163,8 +165,8 @@ static void _pwmout_dev_init() {
// initialize SCT outputs // initialize SCT outputs
for (i = 0; i < CONFIG_SCT_nOU; i++) { for (i = 0; i < CONFIG_SCT_nOU; i++) {
LPC_SCT->OUT[i].SET = (1 << 0); // event 0 will set SCTOUT_xx LPC_SCT->OUT[i].SET = 0; // defer set event until pulsewidth defined
LPC_SCT->OUT[i].CLR = 0; // set clear event when duty cycle LPC_SCT->OUT[i].CLR = (1 << 0); // event 0 clears PWM pin
} }
LPC_SCT->OUTPUT = 0; // default outputs to clear LPC_SCT->OUTPUT = 0; // default outputs to clear
@ -252,15 +254,18 @@ void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
void pwmout_pulsewidth_us(pwmout_t* obj, int us) { void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
// calculate number of ticks // calculate number of ticks
uint32_t v = pwm_clock_mhz * us; uint32_t v = pwm_clock_mhz * us;
uint32_t i = obj->pwm;
//MBED_ASSERT(PWM_GETCOUNT(*PWM_MR0) >= v); //MBED_ASSERT(PWM_GETCOUNT(*PWM_MR0) >= v);
if (v > 0) { if (v > 0) {
// set new match register value and enable SCT output // set new match register value and enable SCT output
*PWM_MR(obj->mr) = PWM_SETCOUNT(v); *PWM_MR(obj->mr) = PWM_SETCOUNT(v);
LPC_SCT->OUT[obj->pwm].CLR = (1 << obj->mr); // on event will clear PWM_XX LPC_SCT->OUT[i].SET = (1 << 0); // event 0 sets PWM pin
LPC_SCT->OUT[i].CLR = (1 << obj->mr); // match event clears PWM pin
} else { } else {
// set match to zero and disable SCT output // set match to zero and clear SCT output
*PWM_MR(obj->mr) = 0; *PWM_MR(obj->mr) = 0;
LPC_SCT->OUT[obj->pwm].CLR = 0; LPC_SCT->OUT[i].SET = 0; // no set event if no pulsewidth defined
LPC_SCT->OUT[i].CLR = (1 << 0); // event 0 clears PWM pin
} }
} }