void pwmout_init(pwmout_t* obj, PinName pin) {
MBED_ASSERT(pin != (uint32_t)NC);
int sct_n = get_available_sct();
if (sct_n == -1) {
error("No available SCT");
}
sct_used |= (1 << sct_n);
obj->pwm = SCTs[sct_n];
obj->pwm_ch = sct_n;
LPC_SCT0_Type* pwm = obj->pwm;
// Enable the SCT clock
LPC_SYSCON->SYSAHBCLKCTRL1 |= (1 << (obj->pwm_ch + 2));
// Clear peripheral reset the SCT:
LPC_SYSCON->PRESETCTRL1 |= (1 << (obj->pwm_ch + 2));
LPC_SYSCON->PRESETCTRL1 &= ~(1 << (obj->pwm_ch + 2));
switch(obj->pwm_ch) {
case 0:
// SCT0_OUT0
LPC_SWM->PINASSIGN[7] &= ~0x0000FF00;
LPC_SWM->PINASSIGN[7] |= (pin << 8);
break;
case 1:
// SCT1_OUT0
LPC_SWM->PINASSIGN[8] &= ~0x000000FF;
LPC_SWM->PINASSIGN[8] |= (pin);
break;
case 2:
// SCT2_OUT0
LPC_SWM->PINASSIGN[8] &= ~0xFF000000;
LPC_SWM->PINASSIGN[8] |= (pin << 24);
break;
case 3:
// SCT3_OUT0
LPC_SWM->PINASSIGN[9] &= ~0x00FF0000;
LPC_SWM->PINASSIGN[9] |= (pin << 16);
break;
default:
break;
}
// Two 16-bit counters, autolimit
pwm->CONFIG &= ~(0x1);
pwm->CONFIG |= (1 << 17);
// 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
pwm->EV0_CTRL = (1 << 12);
pwm->EV0_STATE = 0xFFFFFFFF;
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);
}
void pwmout_init(pwmout_t* obj, PinName pin) {
// determine the SPI to use
PWMName pwm_mapped = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
if (pwm_mapped == (PWMName)NC) {
error("PwmOut pin mapping failed");
}
int sct_n = get_available_sct();
if (sct_n == -1) {
error("No available SCT");
}
sct_used |= (1 << sct_n);
obj->pwm = SCTs[sct_n];
obj->pwm_ch = sct_n;
// Enable the SCT clock
LPC_SYSCON->SYSAHBCLKCTRL |= (1UL << 31);
// Clear peripheral reset the SCT:
LPC_SYSCON->PRESETCTRL |= (1 << (obj->pwm_ch + 9));
pinmap_pinout(pin, PinMap_PWM);
LPC_SCT0_Type* pwm = obj->pwm;
// Two 16-bit counters, autolimit
pwm->CONFIG &= ~(0x1);
pwm->CONFIG |= (1 << 17);
// 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:
pwm->OUT0_SET = (1 << 0); // event 0
pwm->OUT0_CLR = (1 << 1); // event 1
break;
case SCT0_1:
case SCT1_1:
pwm->OUT1_SET = (1 << 0); // event 0
pwm->OUT1_CLR = (1 << 1); // event 1
break;
case SCT0_2:
case SCT1_2:
pwm->OUT2_SET = (1 << 0); // event 0
pwm->OUT2_CLR = (1 << 1); // event 1
break;
case SCT0_3:
case SCT1_3:
pwm->OUT3_SET = (1 << 0); // event 0
pwm->OUT3_CLR = (1 << 1); // event 1
break;
default:
break;
}
// Event 0 : MATCH and MATCHSEL=0
pwm->EV0_CTRL = (1 << 12);
pwm->EV0_STATE = 0xFFFFFFFF;
// 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);
pwmout_write (obj, 0);
}
void pwmout_init(pwmout_t* obj, PinName pin) {
MBED_ASSERT(pin != (uint32_t)NC);
int sct_n = get_available_sct();
if (sct_n == -1) {
error("No available SCT");
}
sct_used |= (1 << sct_n);
obj->pwm = SCTs[sct_n];
obj->pwm_ch = sct_n;
LPC_SCT0_Type* pwm = obj->pwm;
// Enable the SCT clock
LPC_SYSCON->SYSAHBCLKCTRL1 |= (1 << (obj->pwm_ch + 2));
// Clear peripheral reset the SCT:
LPC_SYSCON->PRESETCTRL1 |= (1 << (obj->pwm_ch + 2));
LPC_SYSCON->PRESETCTRL1 &= ~(1 << (obj->pwm_ch + 2));
switch(obj->pwm_ch) {
case 0:
// SCT0_OUT0
LPC_SWM->PINASSIGN[7] &= ~0x0000FF00;
LPC_SWM->PINASSIGN[7] |= (pin << 8);
break;
case 1:
// SCT1_OUT0
LPC_SWM->PINASSIGN[8] &= ~0x000000FF;
LPC_SWM->PINASSIGN[8] |= (pin);
break;
case 2:
// SCT2_OUT0
LPC_SWM->PINASSIGN[8] &= ~0xFF000000;
LPC_SWM->PINASSIGN[8] |= (pin << 24);
break;
case 3:
// SCT3_OUT0
LPC_SWM->PINASSIGN[9] &= ~0x00FF0000;
LPC_SWM->PINASSIGN[9] |= (pin << 16);
break;
default:
break;
}
// Unified 32-bit counter, autolimit
pwm->CONFIG |= ((0x3 << 17) | 0x01);
// halt and clear the counter
pwm->CTRL |= (1 << 2) | (1 << 3);
pwm->OUT0_SET = (1 << 0); // event 0
pwm->OUT0_CLR = (1 << 1); // event 1
pwm->EV0_CTRL = (1 << 12);
pwm->EV0_STATE = 0xFFFFFFFF;
pwm->EV1_CTRL = (1 << 12) | (1 << 0);
pwm->EV1_STATE = 0xFFFFFFFF;
// default to 20ms: standard for servos, and fine for e.g. brightness control
pwmout_period_ms(obj, 20);
pwmout_write (obj, 0);
}
// Any Port pin may be used for PWM.
// Max number of PWM outputs is 4
void pwmout_init(pwmout_t* obj, PinName pin) {
MBED_ASSERT(pin != (uint32_t)NC);
int sct_n = get_available_sct();
if (sct_n == -1) {
error("No available SCT Output");
}
sct_used |= (1 << sct_n);
obj->pwm = (LPC_SCT_TypeDef*)LPC_SCT;
obj->pwm_ch = sct_n;
LPC_SCT_TypeDef* pwm = obj->pwm;
// Init SCT on first use
if (! sct_inited) {
sct_inited = 1;
// Enable the SCT clock
LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 8);
// Clear peripheral reset the SCT:
LPC_SYSCON->PRESETCTRL |= (1 << 8);
// Two 16-bit counters, autolimit (ie reset on Match_0)
//pwm->CONFIG &= ~(0x1);
//pwm->CONFIG |= (1 << 17);
pwm->CONFIG |= ((0x3 << 17) | 0x01);
// halt and clear the counter
pwm->CTRL_U |= (1 << 2) | (1 << 3);
// System Clock (30 Mhz) -> Prescaler -> us_ticker (1 MHz)
pwm->CTRL_U &= ~(0x7F << 5);
pwm->CTRL_U |= (((SystemCoreClock/1000000 - 1) & 0x7F) << 5);
pwm->EVENT[0].CTRL = (1 << 12) | 0; // Event_0 on Match_0
pwm->EVENT[0].STATE = 0xFFFFFFFF; // All states
// unhalt the counter:
// - clearing bit 2 of the CTRL register
pwm->CTRL_U &= ~(1 << 2);
// Not using IRQs
//NVIC_SetVector(PWM_IRQn, (uint32_t)pwm_irq_handler);
//NVIC_EnableIRQ(PWM_IRQn);
}
// LPC81x has only one SCT and 4 Outputs
// LPC82x has only one SCT and 6 Outputs
// LPC1549 has 4 SCTs and 16 Outputs
switch(sct_n) {
case 0:
// SCTx_OUT0
LPC_SWM->PINASSIGN[6] &= ~0xFF000000;
LPC_SWM->PINASSIGN[6] |= (pin << 24);
break;
case 1:
// SCTx_OUT1
LPC_SWM->PINASSIGN[7] &= ~0x000000FF;
LPC_SWM->PINASSIGN[7] |= (pin);
break;
case 2:
// SCTx_OUT2
LPC_SWM->PINASSIGN[7] &= ~0x0000FF00;
LPC_SWM->PINASSIGN[7] |= (pin << 8);
break;
case 3:
// SCTx_OUT3
LPC_SWM->PINASSIGN[7] &= ~0x00FF0000;
LPC_SWM->PINASSIGN[7] |= (pin << 16);
break;
default:
break;
}
pwm->EVENT[sct_n + 1].CTRL = (1 << 12) | (sct_n + 1); // Event_n on Match_n
pwm->EVENT[sct_n + 1].STATE = 0xFFFFFFFF; // All states
pwm->OUT[sct_n].SET = (1 << 0); // All PWM channels are SET on Event_0
pwm->OUT[sct_n].CLR = (1 << (sct_n + 1)); // PWM ch is CLRed on Event_(ch+1)
// default to 20ms: standard for servos, and fine for e.g. brightness control
pwmout_period_ms(obj, 20); // 20ms period
pwmout_write (obj, 0.0); // 0ms pulsewidth, dutycycle 0
}
