//****************************************************************************
//
//! Setup the timer in PWM mode
//!
//! \param ulBase is the base address of the timer to be configured
//! \param ulTimer is the timer to be setup (TIMER_A or TIMER_B)
//! \param ulConfig is the timer configuration setting
//! \param ucInvert is to select the inversion of the output
//!
//! This function
//! 1. The specified timer is setup to operate as PWM
//!
//! \return None.
//
//****************************************************************************
void SetupTimerPWMMode(unsigned long ulBase, unsigned long ulTimer,
unsigned long ulConfig, unsigned char ucInvert)
{
//
// Set GPT - Configured Timer in PWM mode.
//
MAP_TimerConfigure(ulBase,ulConfig);
MAP_TimerPrescaleSet(ulBase,ulTimer,0);
//
// Inverting the timer output if required
//
MAP_TimerControlLevel(ulBase,ulTimer,ucInvert);
//
// Load value set to ~0.5 ms time period
//
MAP_TimerLoadSet(ulBase,ulTimer,TIMER_INTERVAL_RELOAD);
//
// Match value set so as to output level 0
//
MAP_TimerMatchSet(ulBase,ulTimer,TIMER_INTERVAL_RELOAD);
}
void PWMWrite(uint8_t pin, uint32_t analog_res, uint32_t duty, uint32_t freq)
{
analog_res = analog_res * 1000;
freq;
uint32_t load = (F_CPU / freq) * 1000;
uint32_t match = load / (analog_res / duty);
match = match;
load = load / 1000;
uint16_t prescaler = load >> 16;
uint16_t prescaler_match = match >> 16;
uint8_t timer = digitalPinToTimer(pin);
if(timer == NOT_ON_TIMER)
return;
MAP_PRCMPeripheralClkEnable(PRCM_TIMERA0 + (timer/2), PRCM_RUN_MODE_CLK);
uint16_t pnum = digitalPinToPinNum(pin);
switch(timer) {
/* PWM0/1 */
case TIMERA0A:
case TIMERA0B:
MAP_PinTypeTimer(pnum, PIN_MODE_5);
break;
/* PWM2/3 */
case TIMERA1A:
case TIMERA1B:
MAP_PinTypeTimer(pnum, PIN_MODE_9);
break;
/* PWM4/5 */
case TIMERA2A:
case TIMERA2B:
MAP_PinTypeTimer(pnum, PIN_MODE_3);
break;
/* PWM6/7 */
case TIMERA3A:
case TIMERA3B:
MAP_PinTypeTimer(pnum, PIN_MODE_3);
break;
}
uint32_t base = TIMERA0_BASE + ((timer/2) << 12);
/* FIXME: If B is already opperational and configure A, B get's messed up. */
MAP_TimerConfigure(base, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_PWM | TIMER_CFG_B_PWM);
uint16_t timerab = timer % 2 ? TIMER_B : TIMER_A;
MAP_TimerPrescaleSet(base, timerab, prescaler);
MAP_TimerPrescaleMatchSet(base, timerab, prescaler_match);
MAP_TimerControlLevel(base, timerab, 1);
MAP_TimerLoadSet(base, timerab, load);
MAP_TimerMatchSet(base, timerab, match);
MAP_TimerEnable(base, timerab);
}
