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[LPC11U68, LPC1549] Improved PwmOut Documentation 

Improved commenting in pwmout_write(), pwmout_period_us(), and
pwmout_pulsewidth_us().
pull/1587/head
neilt6 2016-03-04 09:23:23 -07:00
parent 792b359a36
commit b3e2763784
2 changed files with 24 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11U6X/pwmout_api.c
View File

@ -137,11 +137,14 @@ void pwmout_write(pwmout_t* obj, float value) {
uint32_t t_on = (uint32_t)((float)(pwm->MATCHREL0 + 1) * value);
if (t_on > 0) {
pwm->MATCHREL1 = t_on - 1;
// Un-halt the timer and ensure the new pulse-width takes immediate effect if necessary
if (pwm->CTRL & (1 << 2)) {
pwm->MATCH1 = pwm->MATCHREL1;
pwm->CTRL &= ~(1 << 2);
}
} else {
// Halt the timer and force the output low
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUTPUT = 0x00000000;
}
@ -174,15 +177,20 @@ void pwmout_period_us(pwmout_t* obj, int us) {
pwm->MATCHREL0 = period_ticks - 1;
if (pulsewidth_ticks > 0) {
pwm->MATCHREL1 = pulsewidth_ticks - 1;
// Un-halt the timer and ensure the new period & pulse-width take immediate effect if necessary
if (pwm->CTRL & (1 << 2)) {
pwm->MATCH0 = pwm->MATCHREL0;
pwm->MATCH1 = pwm->MATCHREL1;
pwm->CTRL &= ~(1 << 2);
}
} else {
// Halt the timer and force the output low
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->MATCH0 = pwm->MATCHREL0;
pwm->OUTPUT = 0x00000000;
// Ensure the new period will take immediate effect when the timer is un-halted
pwm->MATCH0 = pwm->MATCHREL0;
}
}
@ -198,11 +206,14 @@ void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
LPC_SCT0_Type* pwm = obj->pwm;
if (us > 0) {
pwm->MATCHREL1 = (uint32_t)(((uint64_t)SystemCoreClock * (uint64_t)us) / (uint64_t)1000000) - 1;
// Un-halt the timer and ensure the new pulse-width takes immediate effect if necessary
if (pwm->CTRL & (1 << 2)) {
pwm->MATCH1 = pwm->MATCHREL1;
pwm->CTRL &= ~(1 << 2);
}
} else {
// Halt the timer and force the output low
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUTPUT = 0x00000000;
}

13
libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC15XX/pwmout_api.c
View File

@ -118,11 +118,14 @@ void pwmout_write(pwmout_t* obj, float value) {
uint32_t t_on = (uint32_t)((float)(pwm->MATCHREL0 + 1) * value);
if (t_on > 0) {
pwm->MATCHREL1 = t_on - 1;
// Un-halt the timer and ensure the new pulse-width takes immediate effect if necessary
if (pwm->CTRL & (1 << 2)) {
pwm->MATCH1 = pwm->MATCHREL1;
pwm->CTRL &= ~(1 << 2);
}
} else {
// Halt the timer and force the output low
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUTPUT = 0x00000000;
}
@ -155,15 +158,20 @@ void pwmout_period_us(pwmout_t* obj, int us) {
pwm->MATCHREL0 = period_ticks - 1;
if (pulsewidth_ticks > 0) {
pwm->MATCHREL1 = pulsewidth_ticks - 1;
// Un-halt the timer and ensure the new period & pulse-width take immediate effect if necessary
if (pwm->CTRL & (1 << 2)) {
pwm->MATCH0 = pwm->MATCHREL0;
pwm->MATCH1 = pwm->MATCHREL1;
pwm->CTRL &= ~(1 << 2);
}
} else {
// Halt the timer and force the output low
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->MATCH0 = pwm->MATCHREL0;
pwm->OUTPUT = 0x00000000;
// Ensure the new period will take immediate effect when the timer is un-halted
pwm->MATCH0 = pwm->MATCHREL0;
}
}
@ -179,11 +187,14 @@ void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
LPC_SCT0_Type* pwm = obj->pwm;
if (us > 0) {
pwm->MATCHREL1 = (uint32_t)(((uint64_t)SystemCoreClock * (uint64_t)us) / (uint64_t)1000000) - 1;
// Un-halt the timer and ensure the new pulse-width takes immediate effect if necessary
if (pwm->CTRL & (1 << 2)) {
pwm->MATCH1 = pwm->MATCHREL1;
pwm->CTRL &= ~(1 << 2);
}
} else {
// Halt the timer and force the output low
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUTPUT = 0x00000000;
}