[proxmark3-svn] / armsrc / ticks.c

//-----------------------------------------------------------------------------
// Jonathan Westhues, Sept 2005
// Iceman, Sept 2016
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// Timers, Clocks functions used in LF or Legic where you would need detailed time.
//-----------------------------------------------------------------------------
#include "ticks.h"

// attempt at high resolution microsecond timer
// beware: timer counts in 21.3uS increments (1024/48Mhz)
void SpinDelayUs(int us) {
	int ticks = (48 * us) >> 10;

	// Borrow a PWM unit for my real-time clock
	AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0);
	
	// 48 MHz / 1024 gives 46.875 kHz
	AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10);
	AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0;
	AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff;

	uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;

	for(;;) {
		uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;
		if (now == (uint16_t)(start + ticks))
			return;

		WDT_HIT();
	}
}

void SpinDelay(int ms) {
  // convert to uS and call microsecond delay function
	SpinDelayUs(ms*1000);
}
//  -------------------------------------------------------------------------
//  timer lib
//  -------------------------------------------------------------------------
//  test procedure:
//
//	ti = GetTickCount();
//	SpinDelay(1000);
//	ti = GetTickCount() - ti;
//	Dbprintf("timer(1s): %d t=%d", ti, GetTickCount());
void StartTickCount(void) {
	// This timer is based on the slow clock. The slow clock frequency is between 22kHz and 40kHz.
	// We can determine the actual slow clock frequency by looking at the Main Clock Frequency Register.
    uint16_t mainf = AT91C_BASE_PMC->PMC_MCFR & 0xffff;		// = 16 * main clock frequency (16MHz) / slow clock frequency
	// set RealTimeCounter divider to count at 1kHz:
	AT91C_BASE_RTTC->RTTC_RTMR = AT91C_RTTC_RTTRST | ((256000 + (mainf/2)) / mainf);
	// note: worst case precision is approx 2.5%
}

/*
* Get the current count.
*/
uint32_t RAMFUNC GetTickCount(void){
	return AT91C_BASE_RTTC->RTTC_RTVR;// was * 2;
}

//  -------------------------------------------------------------------------
//  microseconds timer 
//  -------------------------------------------------------------------------
void StartCountUS(void) {
	AT91C_BASE_PMC->PMC_PCER |= (1 << 12) | (1 << 13) | (1 << 14);
	AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;

	// fast clock
	// tick=1.5mks
	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
	AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz) / 32 
								AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | AT91C_TC_ACPA_CLEAR |
								AT91C_TC_ACPC_SET | AT91C_TC_ASWTRG_SET;
	AT91C_BASE_TC0->TC_RA = 1;
	AT91C_BASE_TC0->TC_RC = 0xBFFF + 1; // 0xC000
	
	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // timer disable  
	AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_XC1; // from timer 0
	
	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
	AT91C_BASE_TCB->TCB_BCR = 1;
	
	while (AT91C_BASE_TC1->TC_CV >= 1);
}

uint32_t RAMFUNC GetCountUS(void){
	//return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV / 15) * 10);
	//  By suggestion from PwPiwi, http://www.proxmark.org/forum/viewtopic.php?pid=17548#p17548
	return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV * 2) / 3); 
}


//  -------------------------------------------------------------------------
//  Timer for iso14443 commands. Uses ssp_clk from FPGA 
//  -------------------------------------------------------------------------
void StartCountSspClk(void) {
	AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC0) | (1 << AT91C_ID_TC1) | (1 << AT91C_ID_TC2);  // Enable Clock to all timers
	AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_TIOA1 		// XC0 Clock = TIOA1
							| AT91C_TCB_TC1XC1S_NONE 		// XC1 Clock = none
							| AT91C_TCB_TC2XC2S_TIOA0;		// XC2 Clock = TIOA0

	// configure TC1 to create a short pulse on TIOA1 when a rising edge on TIOB1 (= ssp_clk from FPGA) occurs:
	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; 				// disable TC1
	AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_TIMER_DIV1_CLOCK // TC1 Clock = MCK(48MHz)/2 = 24MHz
							| AT91C_TC_CPCSTOP				// Stop clock on RC compare
							| AT91C_TC_EEVTEDG_RISING		// Trigger on rising edge of Event
							| AT91C_TC_EEVT_TIOB			// Event-Source: TIOB1 (= ssp_clk from FPGA = 13,56MHz/16)
							| AT91C_TC_ENETRG				// Enable external trigger event
							| AT91C_TC_WAVESEL_UP	 		// Upmode without automatic trigger on RC compare
							| AT91C_TC_WAVE 				// Waveform Mode
							| AT91C_TC_AEEVT_SET 			// Set TIOA1 on external event
							| AT91C_TC_ACPC_CLEAR; 			// Clear TIOA1 on RC Compare
	AT91C_BASE_TC1->TC_RC = 0x04; 							// RC Compare value = 0x04

	// use TC0 to count TIOA1 pulses
	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;				// disable TC0
	AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_XC0	 			// TC0 clock = XC0 clock = TIOA1
							| AT91C_TC_WAVE 				// Waveform Mode
							| AT91C_TC_WAVESEL_UP	 		// just count
							| AT91C_TC_ACPA_CLEAR 			// Clear TIOA0 on RA Compare
							| AT91C_TC_ACPC_SET; 			// Set TIOA0 on RC Compare
	AT91C_BASE_TC0->TC_RA = 1;								// RA Compare value = 1; pulse width to TC2
	AT91C_BASE_TC0->TC_RC = 0; 								// RC Compare value = 0; increment TC2 on overflow

	// use TC2 to count TIOA0 pulses (giving us a 32bit counter (TC0/TC2) clocked by ssp_clk)
	AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKDIS; 				// disable TC2  
	AT91C_BASE_TC2->TC_CMR = AT91C_TC_CLKS_XC2	 			// TC2 clock = XC2 clock = TIOA0
							| AT91C_TC_WAVE 				// Waveform Mode
							| AT91C_TC_WAVESEL_UP;	 		// just count

	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;				// enable and reset TC0
	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;				// enable and reset TC1
	AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;				// enable and reset TC2

	// synchronize the counter with the ssp_frame signal. 
	// Note: FPGA must be in any iso14443 mode, otherwise the frame signal would not be present 
	while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME)); 	// wait for ssp_frame to go high (start of frame)
	while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME); 		// wait for ssp_frame to be low
	while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)); 	// wait for ssp_clk to go high

	// note: up to now two ssp_clk rising edges have passed since the rising edge of ssp_frame
	// it is now safe to assert a sync signal. This sets all timers to 0 on next active clock edge
	AT91C_BASE_TCB->TCB_BCR = 1;							// assert Sync (set all timers to 0 on next active clock edge)
	// at the next (3rd) ssp_clk rising edge, TC1 will be reset (and not generate a clock signal to TC0)
	// at the next (4th) ssp_clk rising edge, TC0 (the low word of our counter) will be reset. From now on,
	// whenever the last three bits of our counter go 0, we can be sure to be in the middle of a frame transfer.
	// (just started with the transfer of the 4th Bit).

	// The high word of the counter (TC2) will not reset until the low word (TC0) overflows. 
	// Therefore need to wait quite some time before we can use the counter.
	while (AT91C_BASE_TC2->TC_CV >= 1);
}
void ResetSspClk(void) {	
	//enable clock of timer and software trigger
	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
	AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
	while (AT91C_BASE_TC2->TC_CV >= 1);	
}

uint32_t RAMFUNC GetCountSspClk(void) {
	uint32_t tmp_count = (AT91C_BASE_TC2->TC_CV << 16) | AT91C_BASE_TC0->TC_CV;
	if ((tmp_count & 0x0000ffff) == 0)  //small chance that we may have missed an increment in TC2
		return (AT91C_BASE_TC2->TC_CV << 16);
	return tmp_count;
}


//  -------------------------------------------------------------------------
//  Timer for bitbanging,  or LF stuff when you need a very precis timer
//  1us = 1.5ticks
//  -------------------------------------------------------------------------
void StartTicks(void){
	//initialization of the timer
	// tc1 is higher 0xFFFF0000
	// tc0 is lower 0x0000FFFF
	AT91C_BASE_PMC->PMC_PCER |= (1 << 12) | (1 << 13) | (1 << 14);
	AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
	AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz) / 32 
								AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | AT91C_TC_ACPA_CLEAR |
								AT91C_TC_ACPC_SET | AT91C_TC_ASWTRG_SET;
	AT91C_BASE_TC0->TC_RA = 1;
	AT91C_BASE_TC0->TC_RC = 0; 

	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;	// timer disable  
	AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_XC1; // from TC0
	
	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
	AT91C_BASE_TCB->TCB_BCR = 1;
	
	// wait until timer becomes zero.
	while (AT91C_BASE_TC1->TC_CV >= 1);
}
// Wait - Spindelay in ticks.
// if called with a high number, this will trigger the WDT...
void WaitTicks(uint32_t ticks){
	if ( ticks == 0 ) return;
	ticks += GET_TICKS;	
	while (GET_TICKS < ticks);
}
// Wait / Spindelay in us (microseconds) 
// 1us = 1.5ticks.
void WaitUS(uint16_t us){
	if ( us == 0 ) return;
	WaitTicks(  (uint32_t)(us * 1.5) );
}
void WaitMS(uint16_t ms){
	if (ms == 0) return;
	WaitTicks( (uint32_t)(ms * 1500) );
}
// Starts Clock and waits until its reset
void ResetTicks(void){
	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
	while (AT91C_BASE_TC1->TC_CV >= 1);
}
void ResetTimer(AT91PS_TC timer){
	timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
	while(timer->TC_CV >= 1) ;
}
// stop clock
void StopTicks(void){
	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;	
}
Commit	Line	Data
22f4dca8	1	//-----------------------------------------------------------------------------
	2	// Jonathan Westhues, Sept 2005
	3	// Iceman, Sept 2016
	4	//
	5	// This code is licensed to you under the terms of the GNU GPL, version 2 or,
	6	// at your option, any later version. See the LICENSE.txt file for the text of
	7	// the license.
	8	//-----------------------------------------------------------------------------
	9	// Timers, Clocks functions used in LF or Legic where you would need detailed time.
	10	//-----------------------------------------------------------------------------
22f4dca8	11	#include "ticks.h"
	12
	13	// attempt at high resolution microsecond timer
	14	// beware: timer counts in 21.3uS increments (1024/48Mhz)
	15	void SpinDelayUs(int us) {
	16	int ticks = (48 * us) >> 10;
	17
	18	// Borrow a PWM unit for my real-time clock
	19	AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0);
	20
	21	// 48 MHz / 1024 gives 46.875 kHz
	22	AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10);
	23	AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0;
	24	AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff;
	25
	26	uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;
	27
	28	for(;;) {
	29	uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;
	30	if (now == (uint16_t)(start + ticks))
	31	return;
	32
	33	WDT_HIT();
	34	}
	35	}
	36
	37	void SpinDelay(int ms) {
	38	// convert to uS and call microsecond delay function
	39	SpinDelayUs(ms*1000);
	40	}
	41	// -------------------------------------------------------------------------
	42	// timer lib
	43	// -------------------------------------------------------------------------
	44	// test procedure:
	45	//
	46	// ti = GetTickCount();
	47	// SpinDelay(1000);
	48	// ti = GetTickCount() - ti;
	49	// Dbprintf("timer(1s): %d t=%d", ti, GetTickCount());
f8850434	50	void StartTickCount(void) {
22f4dca8	51	// This timer is based on the slow clock. The slow clock frequency is between 22kHz and 40kHz.
	52	// We can determine the actual slow clock frequency by looking at the Main Clock Frequency Register.
	53	uint16_t mainf = AT91C_BASE_PMC->PMC_MCFR & 0xffff; // = 16 * main clock frequency (16MHz) / slow clock frequency
	54	// set RealTimeCounter divider to count at 1kHz:
	55	AT91C_BASE_RTTC->RTTC_RTMR = AT91C_RTTC_RTTRST \| ((256000 + (mainf/2)) / mainf);
	56	// note: worst case precision is approx 2.5%
	57	}
	58
	59	/*
	60	* Get the current count.
	61	*/
f8850434	62	uint32_t RAMFUNC GetTickCount(void){
22f4dca8	63	return AT91C_BASE_RTTC->RTTC_RTVR;// was * 2;
	64	}
	65
	66	// -------------------------------------------------------------------------
	67	// microseconds timer
	68	// -------------------------------------------------------------------------
f8850434	69	void StartCountUS(void) {
22f4dca8	70	AT91C_BASE_PMC->PMC_PCER \|= (1 << 12) \| (1 << 13) \| (1 << 14);
	71	AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE \| AT91C_TCB_TC1XC1S_TIOA0 \| AT91C_TCB_TC2XC2S_NONE;
	72
	73	// fast clock
	74	// tick=1.5mks
	75	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
	76	AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK \| // MCK(48MHz) / 32
	77	AT91C_TC_WAVE \| AT91C_TC_WAVESEL_UP_AUTO \| AT91C_TC_ACPA_CLEAR \|
	78	AT91C_TC_ACPC_SET \| AT91C_TC_ASWTRG_SET;
	79	AT91C_BASE_TC0->TC_RA = 1;
	80	AT91C_BASE_TC0->TC_RC = 0xBFFF + 1; // 0xC000
	81
	82	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // timer disable
	83	AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_XC1; // from timer 0
	84
	85	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG;
	86	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG;
	87	AT91C_BASE_TCB->TCB_BCR = 1;
	88
f8850434	89	while (AT91C_BASE_TC1->TC_CV >= 1);
22f4dca8	90	}
22f4dca8	91
f8850434	92	uint32_t RAMFUNC GetCountUS(void){
22f4dca8	93	//return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV / 15) * 10);
	94	// By suggestion from PwPiwi, http://www.proxmark.org/forum/viewtopic.php?pid=17548#p17548
	95	return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV * 2) / 3);
	96	}
f8850434	97
24c49d36	98
22f4dca8	99	// -------------------------------------------------------------------------
	100	// Timer for iso14443 commands. Uses ssp_clk from FPGA
	101	// -------------------------------------------------------------------------
f8850434	102	void StartCountSspClk(void) {
22f4dca8	103	AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC0) \| (1 << AT91C_ID_TC1) \| (1 << AT91C_ID_TC2); // Enable Clock to all timers
	104	AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_TIOA1 // XC0 Clock = TIOA1
	105	\| AT91C_TCB_TC1XC1S_NONE // XC1 Clock = none
	106	\| AT91C_TCB_TC2XC2S_TIOA0; // XC2 Clock = TIOA0
	107
	108	// configure TC1 to create a short pulse on TIOA1 when a rising edge on TIOB1 (= ssp_clk from FPGA) occurs:
	109	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // disable TC1
	110	AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_TIMER_DIV1_CLOCK // TC1 Clock = MCK(48MHz)/2 = 24MHz
	111	\| AT91C_TC_CPCSTOP // Stop clock on RC compare
	112	\| AT91C_TC_EEVTEDG_RISING // Trigger on rising edge of Event
	113	\| AT91C_TC_EEVT_TIOB // Event-Source: TIOB1 (= ssp_clk from FPGA = 13,56MHz/16)
	114	\| AT91C_TC_ENETRG // Enable external trigger event
	115	\| AT91C_TC_WAVESEL_UP // Upmode without automatic trigger on RC compare
	116	\| AT91C_TC_WAVE // Waveform Mode
	117	\| AT91C_TC_AEEVT_SET // Set TIOA1 on external event
	118	\| AT91C_TC_ACPC_CLEAR; // Clear TIOA1 on RC Compare
	119	AT91C_BASE_TC1->TC_RC = 0x04; // RC Compare value = 0x04
	120
	121	// use TC0 to count TIOA1 pulses
	122	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // disable TC0
	123	AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_XC0 // TC0 clock = XC0 clock = TIOA1
	124	\| AT91C_TC_WAVE // Waveform Mode
	125	\| AT91C_TC_WAVESEL_UP // just count
	126	\| AT91C_TC_ACPA_CLEAR // Clear TIOA0 on RA Compare
	127	\| AT91C_TC_ACPC_SET; // Set TIOA0 on RC Compare
	128	AT91C_BASE_TC0->TC_RA = 1; // RA Compare value = 1; pulse width to TC2
	129	AT91C_BASE_TC0->TC_RC = 0; // RC Compare value = 0; increment TC2 on overflow
	130
	131	// use TC2 to count TIOA0 pulses (giving us a 32bit counter (TC0/TC2) clocked by ssp_clk)
	132	AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKDIS; // disable TC2
	133	AT91C_BASE_TC2->TC_CMR = AT91C_TC_CLKS_XC2 // TC2 clock = XC2 clock = TIOA0
	134	\| AT91C_TC_WAVE // Waveform Mode
	135	\| AT91C_TC_WAVESEL_UP; // just count
	136
	137	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG; // enable and reset TC0
	138	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG; // enable and reset TC1
	139	AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG; // enable and reset TC2
	140
	141	// synchronize the counter with the ssp_frame signal.
	142	// Note: FPGA must be in any iso14443 mode, otherwise the frame signal would not be present
	143	while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME)); // wait for ssp_frame to go high (start of frame)
	144	while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME); // wait for ssp_frame to be low
	145	while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)); // wait for ssp_clk to go high
	146
	147	// note: up to now two ssp_clk rising edges have passed since the rising edge of ssp_frame
	148	// it is now safe to assert a sync signal. This sets all timers to 0 on next active clock edge
	149	AT91C_BASE_TCB->TCB_BCR = 1; // assert Sync (set all timers to 0 on next active clock edge)
	150	// at the next (3rd) ssp_clk rising edge, TC1 will be reset (and not generate a clock signal to TC0)
	151	// at the next (4th) ssp_clk rising edge, TC0 (the low word of our counter) will be reset. From now on,
	152	// whenever the last three bits of our counter go 0, we can be sure to be in the middle of a frame transfer.
	153	// (just started with the transfer of the 4th Bit).
	154
	155	// The high word of the counter (TC2) will not reset until the low word (TC0) overflows.
	156	// Therefore need to wait quite some time before we can use the counter.
f8850434	157	while (AT91C_BASE_TC2->TC_CV >= 1);
22f4dca8	158	}
	159	void ResetSspClk(void) {
	160	//enable clock of timer and software trigger
	161	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG;
	162	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG;
	163	AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG;
f8850434	164	while (AT91C_BASE_TC2->TC_CV >= 1);
22f4dca8	165	}
22f4dca8	166
f8850434	167	uint32_t RAMFUNC GetCountSspClk(void) {
22f4dca8	168	uint32_t tmp_count = (AT91C_BASE_TC2->TC_CV << 16) \| AT91C_BASE_TC0->TC_CV;
	169	if ((tmp_count & 0x0000ffff) == 0) //small chance that we may have missed an increment in TC2
	170	return (AT91C_BASE_TC2->TC_CV << 16);
	171	return tmp_count;
	172	}
	173
	174
24c49d36	175	// -------------------------------------------------------------------------
	176	// Timer for bitbanging, or LF stuff when you need a very precis timer
	177	// 1us = 1.5ticks
	178	// -------------------------------------------------------------------------
22f4dca8	179	void StartTicks(void){
22f4dca8	180	//initialization of the timer
fabef615	181	// tc1 is higher 0xFFFF0000
fabef615	182	// tc0 is lower 0x0000FFFF
22f4dca8	183	AT91C_BASE_PMC->PMC_PCER \|= (1 << 12) \| (1 << 13) \| (1 << 14);
22f4dca8	184	AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE \| AT91C_TCB_TC1XC1S_TIOA0 \| AT91C_TCB_TC2XC2S_NONE;
24c49d36	185	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
fabef615	186	AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK \| // MCK(48MHz) / 32
	187	AT91C_TC_WAVE \| AT91C_TC_WAVESEL_UP_AUTO \| AT91C_TC_ACPA_CLEAR \|
	188	AT91C_TC_ACPC_SET \| AT91C_TC_ASWTRG_SET;
	189	AT91C_BASE_TC0->TC_RA = 1;
c649c433	190	AT91C_BASE_TC0->TC_RC = 0;
fabef615	191
	192	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // timer disable
	193	AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_XC1; // from TC0
	194
22f4dca8	195	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG;
fabef615	196	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG;
22f4dca8	197	AT91C_BASE_TCB->TCB_BCR = 1;
fabef615	198
22f4dca8	199	// wait until timer becomes zero.
fabef615	200	while (AT91C_BASE_TC1->TC_CV >= 1);
22f4dca8	201	}
	202	// Wait - Spindelay in ticks.
	203	// if called with a high number, this will trigger the WDT...
	204	void WaitTicks(uint32_t ticks){
	205	if ( ticks == 0 ) return;
	206	ticks += GET_TICKS;
	207	while (GET_TICKS < ticks);
	208	}
	209	// Wait / Spindelay in us (microseconds)
	210	// 1us = 1.5ticks.
	211	void WaitUS(uint16_t us){
	212	if ( us == 0 ) return;
	213	WaitTicks( (uint32_t)(us * 1.5) );
	214	}
	215	void WaitMS(uint16_t ms){
	216	if (ms == 0) return;
	217	WaitTicks( (uint32_t)(ms * 1500) );
	218	}
	219	// Starts Clock and waits until its reset
d41efbf2	220	void ResetTicks(void){
fabef615	221	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG;
	222	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG;
	223	while (AT91C_BASE_TC1->TC_CV >= 1);
22f4dca8	224	}
	225	void ResetTimer(AT91PS_TC timer){
	226	timer->TC_CCR = AT91C_TC_CLKEN \| AT91C_TC_SWTRG;
d5bded10	227	while(timer->TC_CV >= 1) ;
22f4dca8	228	}
d41efbf2	229	// stop clock
	230	void StopTicks(void){
	231	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
	232	AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
	233	}