/**************************************************************************//**
* @brief Transmit null-terminated string to BOOTLOADER_USART
*****************************************************************************/
__ramfunc void USART_printString(uint8_t *string)
{
while (*string != 0)
{
USART_txByte(*string++);
}
}
/***************************************************************************//**
* @brief
* Prints an int in hex.
*
* @param integer
* The integer to be printed.
******************************************************************************/
__ramfunc void USART_printHex(uint32_t integer)
{
uint8_t c;
int i, digit;
for (i = 0; i <= 7; i++)
{
digit = integer >> 28;
c = digit + 0x30;
if (digit >= 10)
{
c += 7;
}
USART_txByte(c);
integer <<= 4;
}
}
/**************************************************************************//**
* @brief Decode single byte to BOOTLOADER_Hijack
*****************************************************************************/
__ramfunc uint8_t dec_rxByte(void)
{
uint8_t ch;
//while ( !decBuf.pendingBytes ) ;
/* Copy data from buffer */
#if CRITICAL_PROTECTION==1
INT_Disable();
#endif
ch = decBuf.data[decBuf.rdI];
decBuf.rdI = (decBuf.rdI + 1) % BUFFERSIZE;
/* Decrement pending byte counter */
decBuf.pendingBytes--;
#if CRITICAL_PROTECTION==1
INT_Enable();
#endif
USART_txByte( ch ) ;
return( ch );
}
/**************************************************************************//**
* @brief TIMER0_setup
* Configures the TIMER
*****************************************************************************/
void TIMER_setup(void)
{
/* Enable necessary clocks */
CMU_ClockEnable(cmuClock_TIMER0, true);
CMU_ClockEnable(cmuClock_PRS, true);
/* Select CC channel parameters */
TIMER_InitCC_TypeDef timerCCInit =
{
.eventCtrl = timerEventEveryEdge, /* Input capture event control */
.edge = timerEdgeBoth, /* Input capture on falling edge */
.prsSel = timerPRSSELCh5, /* 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 channel */
TIMER_InitCC(HIJACK_RX_TIMER, 0, &timerCCInit);
/* Select timer parameters */
const TIMER_Init_TypeDef timerInit =
{
.enable = false, /* Do not start counting when init complete */
.debugRun = false, /* Counter not running on debug halt */
.prescale = HIJACK_TIMER_RESOLUTION, /* Prescaler of 1 */
.clkSel = timerClkSelHFPerClk, /* TIMER0 clocked by the HFPERCLK */
.fallAction = timerInputActionReloadStart, /* Stop counter on falling edge */
.riseAction = timerInputActionReloadStart, /* 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(HIJACK_RX_TIMER, &timerInit);
/* PRS setup */
/* Select ACMP as source and ACMP0OUT (ACMP0 OUTPUT) as signal */
PRS_SourceSignalSet(5, PRS_CH_CTRL_SOURCESEL_ACMP0, PRS_CH_CTRL_SIGSEL_ACMP0OUT, prsEdgeOff);
/* Enable CC0 interrupt */
TIMER_IntEnable(HIJACK_RX_TIMER, TIMER_IF_CC0);
/* Enable TIMER0 interrupt vector in NVIC */
NVIC_EnableIRQ(TIMER0_IRQn);
}
/**************************************************************************//**
* @brief ACMP_setup
* Configures and starts the ACMP
*****************************************************************************/
static void ACMP_setup(void)
{
/* Enable necessary clocks */
CMU_ClockEnable(HIJACK_RX_ACMPCLK, true);
CMU_ClockEnable(cmuClock_GPIO, true);
/* Configure ACMP input pin. */
GPIO_PinModeSet(HIJACK_RX_GPIO_PORT, HIJACK_RX_GPIO_PIN, gpioModeInput, 0);
/* Analog comparator parameters */
const ACMP_Init_TypeDef acmpInit =
{
.fullBias = false, /* No full bias current*/
.halfBias = true, /* No half bias current */
.biasProg = 2, /* 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 = acmpHysteresisLevel7, /* Hysteresis level 0 - no hysteresis */
.inactiveValue = 1, /* Inactive comparator output value */
.lowPowerReferenceEnabled = false, /* Low power reference mode disabled */
.vddLevel = HIJACK_RX_ACMP_LEVEL, /* Vdd reference scaling of 32 */
};
/* Use ACMP0 output, PD6 . */
//GPIO_PinModeSet(gpioPortD, 6, gpioModePushPull, 0);
//ACMP_GPIOSetup(ACMP0, 2, true, false);
/* Init ACMP and set ACMP channel 4 as positive input
and scaled Vdd as negative input */
ACMP_Init(HIJACK_RX_ACMP, &acmpInit);
ACMP_ChannelSet(HIJACK_RX_ACMP, HIJACK_RX_ACMP_NEG, HIJACK_RX_ACMP_CH);
ACMP_Enable(HIJACK_RX_ACMP);
}
/**
* @brief calculate whether cnt is in 500us region
* ticker = 64Mhz/128 = 2us
* 475us < cnt < 510us
*
*/
static chk_result_t IsTime2Detect(uint32_t inv)
{
chk_result_t ret;
if( inv < HIJACK_DEC_NUM_TICKS_MIN){
offset = inv;
ret = pass;
}
else if ( ( inv <= HIJACK_DEC_NUM_TICKS_MAX ) && ( inv >= HIJACK_DEC_NUM_TICKS_MIN ) ) {
offset = 0;
inv = 0;
ret = suit;
}
else{
offset = 0;
inv = 0;
ret = error;
}
return ret;
}
/*
* Find phase remain or phase reversal.
*/
static void dec_parser(uint8_t bit_msk, state_t state)
{
if ( ( suit == IsTime2Detect(inv) ) ){ //it's time to determine
if( falling == cur_edge ){
dec.data &= ~(1 << bit_msk);
#if DEC_DEBUG == 1
uartPutChar( '+' ) ;
uartPutChar( '_' ) ;
#endif//DEC_DEBUG == 1
}
else{
dec.data |= (1 << bit_msk);
#if DEC_DEBUG == 1
uartPutChar( '_' ) ;
uartPutChar( '+' ) ;
#endif//DEC_DEBUG == 1
dec.odd++;
}
dec.state = state; //state switch
}
else if ( error == IsTime2Detect(inv) ){ //wait for edge detection time
dec.state = Waiting; //state switch
}
}
/**************************************************************************//**
* @brief decode state machine
* Invoke in TIMER_ISR for decoding.
*****************************************************************************/
void decode_machine(void)
{
inv = offset + cur_stamp; //update offset
#if 0
if( dec.state > Waiting ){
USART_printHexBy16u(inv);
if(cur_edge == rising){
uartPutChar( '\\' ) ;
}
else{
uartPutChar( '/' ) ;
}
}
#endif
switch (dec.state){
case Waiting:
/* go to start bit if rising edge exist. */
if (rising == cur_edge) {
dec.state = Sta0;
offset = 0;
inv = 0;
}
break;
//
case Sta0:
if( ( suit == IsTime2Detect(inv) ) && ( falling == cur_edge ) ){
dec.data = 0; //clear data field for store new potential data
dec.odd = 0; //clear odd field parity counter
dec.state = Bit0;
#if DEC_DEBUG == 1
uartPutChar( 'S' ) ;
uartPutChar( '+' ) ;
uartPutChar( '_' ) ;
#endif
}
else{
dec.state = Waiting;
}
break;
//
case Bit0:
#if DEC_DEBUG == 1
uartPutChar( '0' ) ;
#endif
dec_parser(BIT0, Bit1);
break;
//
case Bit1:
#if DEC_DEBUG == 1
uartPutChar( '1' ) ;
#endif
dec_parser(BIT1, Bit2);
break;
//
case Bit2:
#if DEC_DEBUG == 1
uartPutChar( '2' ) ;
#endif
dec_parser(BIT2, Bit3);
break;
//
case Bit3:
#if DEC_DEBUG == 1
uartPutChar( '3' ) ;
#endif
dec_parser(BIT3, Bit4);
break;
//
case Bit4:
#if DEC_DEBUG == 1
uartPutChar( '4' ) ;
#endif
dec_parser(BIT4, Bit5);
break;
//
case Bit5:
#if DEC_DEBUG == 1
uartPutChar( '5' ) ;
#endif
dec_parser(BIT5, Bit6);
break;
//
case Bit6:
#if DEC_DEBUG == 1
uartPutChar( '6' ) ;
#endif
dec_parser(BIT6, Bit7);
break;
//
case Bit7:
#if DEC_DEBUG == 1
uartPutChar( '7' ) ;
#endif
dec_parser(BIT7, Parity);
break;
//
case Parity:
if ( ( suit == IsTime2Detect(inv) ) ){ //it's time to determine
if( rising == cur_edge ){
dec.odd++;
#if DEC_DEBUG == 1
uartPutChar( '_' ) ;
uartPutChar( '+' ) ;
#endif
}
else{
#if DEC_DEBUG == 1
uartPutChar( '+' ) ;
uartPutChar( '_' ) ;
#endif
}
#if DEC_DEBUG == 1
uartPutChar( dec.odd + 0x30) ;
#endif
if( 1 == (dec.odd%2)){ //parity pass
dec.state = Sto0;
}
else{ //parity failed
dec.state = Waiting;
}
}
else if ( error == IsTime2Detect(inv) ){ //wait for edge detection time
dec.state = Waiting;
}
break;
//
case Sto0:
if ( ( suit == IsTime2Detect(inv) ) ){ //it's time to determine
if( rising == cur_edge ){ //stop bit is rising edge
USART_txByte(dec.data);
#if DEC_DEBUG == 1
uartPutChar( '_' ) ;
uartPutChar( '+' ) ;
#endif
HIJACKPutData(&dec.data, &decBuf, sizeof(uint8_t));
}
else{
#if DEC_DEBUG == 1
uartPutChar( '+' ) ;
uartPutChar( '_' ) ;
#endif
}
dec.state = Waiting;
#if DEC_DEBUG == 1
uartPutChar( '\r' ) ;
uartPutChar( '\n' ) ;
#endif
}
else if ( error == IsTime2Detect(inv) ){ //wait for edge detection time
dec.state = Waiting;
}
break;
//
default:
break;
//
}
}
