/**************************************************************************//**
* @brief decode peripheral initial.
*****************************************************************************/
void dec_init(void)
{
/* Initialise the ACMP */
ACMP_setup();
/* Initialise the TIMER */
TIMER_setup();
}
/**************************************************************************//**
* @brief ACMP_setup
* Configures and starts the ACMP
*****************************************************************************/
void ACMP_setup(void)
{
/* Enable necessary clocks */
CMU_ClockEnable(cmuClock_ACMP0, true);
CMU_ClockEnable(cmuClock_GPIO, true);
/* Configure PC4 as input with pull down for ACMP channel 4 input */
GPIO_PinModeSet(gpioPortC, 4, gpioModeInputPullFilter, 0);
/* Analog comparator parameters */
const ACMP_Init_TypeDef acmpInit =
{
.fullBias = false, /* no full bias current*/
.halfBias = false, /* no half bias current */
.biasProg = 7, /* Biasprog current 1.4 uA */
.interruptOnFallingEdge = false, /* disable interrupt for falling edge */
.interruptOnRisingEdge = false, /* disable interrupt for rising edge */
.warmTime = acmpWarmTime256, /* Warm-up time in clock cycles, should be >140 cycles for >10us warm-up @ 14MHz */
.hysteresisLevel = acmpHysteresisLevel0, /* Hysteresis level 0 - no hysteresis */
.inactiveValue = 0, /* Inactive comparator output value */
.lowPowerReferenceEnabled = false, /* Low power reference mode disabled */
.vddLevel = 32, /* Vdd reference scaling of 32 */
};
/* Init ACMP and set ACMP channel 4 as positive input
and scaled Vdd as negative input */
ACMP_Init(ACMP0, &acmpInit);
ACMP_ChannelSet(ACMP0, acmpChannelVDD, acmpChannel4);
ACMP_Enable(ACMP0);
}
/**************************************************************************//**
* @brief PRS_ScanChannel
* Waits for activity on a selected PRS channel and writes on the LCD
when activity occurs
*
* @param[in] timer
* Pointer to TIMER peripheral register block.
*
* @param[in] prsCh
* PRS Channel to be monitored
*
* @param[in] edgeType
* Signal edge to be monitored/captured
*****************************************************************************/
void PRS_ScanChannel(TIMER_TypeDef *timer, TIMER_PRSSEL_TypeDef prsCh, TIMER_Edge_TypeDef edgeType)
{
/* enable the clock for the correct timer */
#define TIMER_Clock(T) (T==TIMER0 ? cmuClock_TIMER0 : \
T==TIMER1 ? cmuClock_TIMER1 : 0)
/* Enable necessary clocks */
CMU_ClockEnable((CMU_Clock_TypeDef)TIMER_Clock(timer), true);
/* Initialize LCD */
SegmentLCD_Init(false);
/* Select CC channel parameters */
const TIMER_InitCC_TypeDef timerCCInit =
{
.eventCtrl = timerEventFalling, /* input capture event control */
.edge = edgeType, /* input capture on falling edge */
.prsSel = prsCh, /* prs channel select channel 5*/
.cufoa = timerOutputActionNone, /* no action on counter underflow */
.cofoa = timerOutputActionNone, /* no action on counter overflow */
.cmoa = timerOutputActionNone, /* no action on counter match */
.mode = timerCCModeCapture, /* CC channel mode capture */
.filter = false, /* no filter */
.prsInput = true, /* CC channel PRS input */
.coist = false, /* comparator output initial state */
.outInvert = false, /* no output invert */
};
/* Initialize TIMER0 CC0 */
TIMER_InitCC(timer, 0, &timerCCInit);
/* Select timer parameters */
const TIMER_Init_TypeDef timerInit =
{
.enable = true, /* start counting when init complete */
.debugRun = false, /* counter not running on debug halt */
.prescale = timerPrescale1024, /* prescaler of 64 */
.clkSel = timerClkSelHFPerClk, /* TIMER0 clocked by the HFPERCLK */
.fallAction = timerInputActionNone, /* stop counter on falling edge */
.riseAction = timerInputActionNone, /* reload and start on rising edge */
.mode = timerModeUp, /* counting up */
.dmaClrAct = false, /* no DMA */
.quadModeX4 = false, /* no quad decoding */
.oneShot = false, /* counting up constinuously */
.sync = false, /* no start/stop/reload by other timers */
};
/* Initialize TIMER0 */
TIMER_Init(timer, &timerInit);
/* Poll the Input Capture Valid flag in the Status register
The program will hang at this point waiting for activity on this
channel */
while(!((TIMER0->STATUS & _TIMER_STATUS_ICV0_MASK )>>16));
}
/**************************************************************************//**
* @brief Main function
* Main is called from __iar_program_start, see assembly startup file
*****************************************************************************/
int main(void)
{
/* Align different chip revisions*/
CHIP_Init();
/* Initialise the ACMP */
ACMP_setup();
/* PRS setup */
/* Enable clock for PRS and select ACMP as source and ACMP0OUT (ACMP0 OUTPUT) as signal
for channel 5 */
CMU_ClockEnable(cmuClock_PRS, true);
PRS_SourceSignalSet(5, PRS_CH_CTRL_SOURCESEL_ACMP0, PRS_CH_CTRL_SIGSEL_ACMP0OUT, prsEdgeOff);
/* Start PRS scan
This function will halt the program while there is no PRS activity
This function assumes that the PRS has been setup previously */
PRS_ScanChannel(TIMER0, timerPRSSELCh5, timerEdgeFalling);
/* Write PRS and channel number on the LCD to acknowledge PRS activity */
SegmentLCD_Write("PRS");
SegmentLCD_Number((int)timerPRSSELCh5);
while(1)
{
/* Enter EM1 while waiting for capture. */
EMU_EnterEM1();
}
}
