proxmark3/armsrc/ticks.c
2019-03-09 08:59:13 +01:00

240 lines
10 KiB
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); // Channel Mode Register
AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0; // Channel Duty Cycle Register
AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff; // Channel Period Register
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 << AT91C_ID_TC0) | (1 << AT91C_ID_TC1);
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 > 0);
}
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 ((uint32_t)AT91C_BASE_TC1->TC_CV) * 0x8000 + (((uint32_t)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 > 0);
}
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 > 0);
}
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
AT91C_BASE_PMC->PMC_PCER |= (1 << AT91C_ID_TC0) | (1 << AT91C_ID_TC1);
AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
// disable TC0 and TC1 for re-configuration
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
// first configure TC1 (higher, 0xFFFF0000) 16 bit counter
AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_XC1; // just connect to TIOA0 from TC0
AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // re-enable timer and wait for TC0
// second configure TC0 (lower, 0x0000FFFF) 16 bit counter
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 | // RA comperator clears TIOA (carry bit)
AT91C_TC_ACPC_SET | // RC comperator sets TIOA (carry bit)
AT91C_TC_ASWTRG_SET; // SWTriger sets TIOA (carry bit)
AT91C_BASE_TC0->TC_RC = 0; // set TIOA (carry bit) on overflow, return to zero
AT91C_BASE_TC0->TC_RA = 1; // clear carry bit on next clock cycle
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // reset and re-enable timer
// synchronized startup procedure
while (AT91C_BASE_TC0->TC_CV > 0); // wait until TC0 returned to zero
while (AT91C_BASE_TC0->TC_CV < 2); // and has started (TC_CV > TC_RA, now TC1 is cleared)
// return to zero
AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG;
AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG;
while (AT91C_BASE_TC0->TC_CV > 0);
}
uint32_t GetTicks(void) {
uint32_t hi, lo;
do {
hi = AT91C_BASE_TC1->TC_CV;
lo = AT91C_BASE_TC0->TC_CV;
} while(hi != AT91C_BASE_TC1->TC_CV);
return (hi << 16) | lo;
}
// 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 += GetTicks();
while (GetTicks() < ticks);
}
// Wait / Spindelay in us (microseconds)
// 1us = 1.5ticks.
void WaitUS(uint16_t us){
WaitTicks( (uint32_t)us * 3/2 );
}
void WaitMS(uint16_t ms){
WaitTicks( (uint32_t)ms * 1500 );
}
// stop clock
void StopTicks(void){
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
}