Skip to content

[LPC11U68, LPC1549] Fixed PwmOut SCT Bugs #1512

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jan 30, 2016
Merged

[LPC11U68, LPC1549] Fixed PwmOut SCT Bugs #1512

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
53 changes: 32 additions & 21 deletions libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11U6X/pwmout_api.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -83,10 +83,6 @@ void pwmout_init(pwmout_t* obj, PinName pin) {
// halt and clear the counter
pwm->CTRL |= (1 << 2) | (1 << 3);

// System Clock -> us_ticker (1)MHz
pwm->CTRL &= ~(0x7F << 5);
pwm->CTRL |= (((SystemCoreClock/1000000 - 1) & 0x7F) << 5);

switch(pwm_mapped) {
case SCT0_0:
case SCT1_0:
Expand Down Expand Up @@ -117,14 +113,6 @@ void pwmout_init(pwmout_t* obj, PinName pin) {
// Event 1 : MATCH and MATCHSEL=1
pwm->EV1_CTRL = (1 << 12) | (1 << 0);
pwm->EV1_STATE = 0xFFFFFFFF;

// Match reload register
pwm->MATCHREL0 = 20000; // 20ms
pwm->MATCHREL1 = (pwm->MATCHREL0 / 4); // 50% duty

// unhalt the counter:
// - clearing bit 2 of the CTRL register
pwm->CTRL &= ~(1 << 2);

// default to 20ms: standard for servos, and fine for e.g. brightness control
pwmout_period_ms(obj, 20);
Expand All @@ -140,18 +128,25 @@ void pwmout_free(pwmout_t* obj) {
}

void pwmout_write(pwmout_t* obj, float value) {
LPC_SCT0_Type* pwm = obj->pwm;
if (value < 0.0f) {
value = 0.0;
} else if (value > 1.0f) {
value = 1.0;
}
uint32_t t_on = (uint32_t)((float)(obj->pwm->MATCHREL0) * value);
obj->pwm->MATCHREL1 = t_on;
uint32_t t_on = (uint32_t)((float)(pwm->MATCHREL0 + 1) * value);
if (t_on > 0) {
pwm->MATCHREL1 = t_on - 1;
pwm->CTRL &= ~(1 << 2);
} else {
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUTPUT = 0x00000000;
}
}

float pwmout_read(pwmout_t* obj) {
uint32_t t_off = obj->pwm->MATCHREL0;
uint32_t t_on = obj->pwm->MATCHREL1;
uint32_t t_off = obj->pwm->MATCHREL0 + 1;
uint32_t t_on = obj->pwm->MATCHREL1 + 1;
float v = (float)t_on/(float)t_off;
return (v > 1.0f) ? (1.0f) : (v);
}
Expand All @@ -166,11 +161,20 @@ void pwmout_period_ms(pwmout_t* obj, int ms) {

// Set the PWM period, keeping the duty cycle the same.
void pwmout_period_us(pwmout_t* obj, int us) {
uint32_t t_off = obj->pwm->MATCHREL0;
uint32_t t_on = obj->pwm->MATCHREL1;
LPC_SCT0_Type* pwm = obj->pwm;
uint32_t t_off = pwm->MATCHREL0 + 1;
uint32_t t_on = pwm->MATCHREL1 + 1;
float v = (float)t_on/(float)t_off;
obj->pwm->MATCHREL0 = (uint32_t)us;
obj->pwm->MATCHREL1 = (uint32_t)((float)us * (float)v);
uint32_t period_ticks = (uint32_t)(((uint64_t)SystemCoreClock * (uint64_t)us) / (uint64_t)1000000);
uint32_t pulsewidth_ticks = period_ticks * v;
pwm->MATCHREL0 = period_ticks - 1;
if (pulsewidth_ticks > 0) {
pwm->MATCHREL1 = pulsewidth_ticks - 1;
pwm->CTRL &= ~(1 << 2);
} else {
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUTPUT = 0x00000000;
}
}

void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
Expand All @@ -182,7 +186,14 @@ void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
}

void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
obj->pwm->MATCHREL1 = (uint32_t)us;
LPC_SCT0_Type* pwm = obj->pwm;
if (us > 0) {
pwm->MATCHREL1 = (uint32_t)(((uint64_t)SystemCoreClock * (uint64_t)us) / (uint64_t)1000000) - 1;
pwm->CTRL &= ~(1 << 2);
} else {
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUTPUT = 0x00000000;
}
}

#endif
51 changes: 30 additions & 21 deletions libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC15XX/pwmout_api.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -89,14 +89,6 @@ void pwmout_init(pwmout_t* obj, PinName pin) {
// halt and clear the counter
pwm->CTRL |= (1 << 2) | (1 << 3);

// System Clock -> us_ticker (1)MHz
pwm->CTRL &= ~(0x7F << 5);
pwm->CTRL |= (((SystemCoreClock/1000000 - 1) & 0x7F) << 5);

// Match reload register
pwm->MATCHREL0 = 20000; // 20ms
pwm->MATCHREL1 = (pwm->MATCHREL0 / 4); // 50% duty

pwm->OUT0_SET = (1 << 0); // event 0
pwm->OUT0_CLR = (1 << 1); // event 1

Expand All @@ -105,10 +97,6 @@ void pwmout_init(pwmout_t* obj, PinName pin) {
pwm->EV1_CTRL = (1 << 12) | (1 << 0);
pwm->EV1_STATE = 0xFFFFFFFF;

// unhalt the counter:
// - clearing bit 2 of the CTRL register
pwm->CTRL &= ~(1 << 2);

// default to 20ms: standard for servos, and fine for e.g. brightness control
pwmout_period_ms(obj, 20);
pwmout_write (obj, 0);
Expand All @@ -127,13 +115,19 @@ void pwmout_write(pwmout_t* obj, float value) {
} else if (value > 1.0f) {
value = 1.0;
}
uint32_t t_on = (uint32_t)((float)(pwm->MATCHREL0) * value);
pwm->MATCHREL1 = t_on;
uint32_t t_on = (uint32_t)((float)(pwm->MATCHREL0 + 1) * value);
if (t_on > 0) {
pwm->MATCHREL1 = t_on - 1;
pwm->CTRL &= ~(1 << 2);
} else {
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUTPUT = 0x00000000;
}
}

float pwmout_read(pwmout_t* obj) {
uint32_t t_off = obj->pwm->MATCHREL0;
uint32_t t_on = obj->pwm->MATCHREL1;
uint32_t t_off = obj->pwm->MATCHREL0 + 1;
uint32_t t_on = obj->pwm->MATCHREL1 + 1;
float v = (float)t_on/(float)t_off;
return (v > 1.0f) ? (1.0f) : (v);
}
Expand All @@ -149,11 +143,19 @@ void pwmout_period_ms(pwmout_t* obj, int ms) {
// Set the PWM period, keeping the duty cycle the same.
void pwmout_period_us(pwmout_t* obj, int us) {
LPC_SCT0_Type* pwm = obj->pwm;
uint32_t t_off = pwm->MATCHREL0;
uint32_t t_on = pwm->MATCHREL1;
uint32_t t_off = pwm->MATCHREL0 + 1;
uint32_t t_on = pwm->MATCHREL1 + 1;
float v = (float)t_on/(float)t_off;
pwm->MATCHREL0 = (uint32_t)us;
pwm->MATCHREL1 = (uint32_t)((float)us * (float)v);
uint32_t period_ticks = (uint32_t)(((uint64_t)SystemCoreClock * (uint64_t)us) / (uint64_t)1000000);
uint32_t pulsewidth_ticks = period_ticks * v;
pwm->MATCHREL0 = period_ticks - 1;
if (pulsewidth_ticks > 0) {
pwm->MATCHREL1 = pulsewidth_ticks - 1;
pwm->CTRL &= ~(1 << 2);
} else {
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUTPUT = 0x00000000;
}
}

void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
Expand All @@ -165,6 +167,13 @@ void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
}

void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
obj->pwm->MATCHREL1 = (uint32_t)us;
LPC_SCT0_Type* pwm = obj->pwm;
if (us > 0) {
pwm->MATCHREL1 = (uint32_t)(((uint64_t)SystemCoreClock * (uint64_t)us) / (uint64_t)1000000) - 1;
pwm->CTRL &= ~(1 << 2);
} else {
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUTPUT = 0x00000000;
}
}