-//-----------------------------------------------------------------------------\r
-// Utility functions used in many places, not specific to any piece of code.\r
-// Jonathan Westhues, Sept 2005\r
-//-----------------------------------------------------------------------------\r
-#include <proxmark3.h>\r
-#include "apps.h"\r
-\r
-void *memcpy(void *dest, const void *src, int len)\r
-{\r
- BYTE *d = dest;\r
- const BYTE *s = src;\r
- while((len--) > 0) {\r
- *d = *s;\r
- d++;\r
- s++;\r
- }\r
- return dest;\r
-}\r
-\r
-void *memset(void *dest, int c, int len)\r
-{\r
- BYTE *d = dest;\r
- while((len--) > 0) {\r
- *d = c;\r
- d++;\r
- }\r
- return dest;\r
-}\r
-\r
-int memcmp(const void *av, const void *bv, int len)\r
-{\r
- const BYTE *a = av;\r
- const BYTE *b = bv;\r
-\r
- while((len--) > 0) {\r
- if(*a != *b) {\r
- return *a - *b;\r
- }\r
- a++;\r
- b++;\r
- }\r
- return 0;\r
-}\r
-\r
-int strlen(char *str)\r
-{\r
- int l = 0;\r
- while(*str) {\r
- l++;\r
- str++;\r
- }\r
- return l;\r
-}\r
-\r
-void LEDsoff()\r
-{\r
- LED_A_OFF();\r
- LED_B_OFF();\r
- LED_C_OFF();\r
- LED_D_OFF();\r
-}\r
-\r
-// LEDs: R(C) O(A) G(B) -- R(D) [1, 2, 4 and 8]\r
-void LED(int led, int ms)\r
-{\r
- if (led & LED_RED)\r
- LED_C_ON();\r
- if (led & LED_ORANGE)\r
- LED_A_ON();\r
- if (led & LED_GREEN)\r
- LED_B_ON();\r
- if (led & LED_RED2)\r
- LED_D_ON();\r
-\r
- if (!ms)\r
- return;\r
-\r
- SpinDelay(ms);\r
-\r
- if (led & LED_RED)\r
- LED_C_OFF();\r
- if (led & LED_ORANGE)\r
- LED_A_OFF();\r
- if (led & LED_GREEN)\r
- LED_B_OFF();\r
- if (led & LED_RED2)\r
- LED_D_OFF();\r
-}\r
-\r
-\r
-// Determine if a button is double clicked, single clicked,\r
-// not clicked, or held down (for ms || 1sec)\r
-// In general, don't use this function unless you expect a\r
-// double click, otherwise it will waste 500ms -- use BUTTON_HELD instead\r
-int BUTTON_CLICKED(int ms)\r
-{\r
- // Up to 500ms in between clicks to mean a double click\r
- int ticks = (48000 * (ms ? ms : 1000)) >> 10;\r
-\r
- // If we're not even pressed, forget about it!\r
- if (!BUTTON_PRESS())\r
- return BUTTON_NO_CLICK;\r
-\r
- // Borrow a PWM unit for my real-time clock\r
- PWM_ENABLE = PWM_CHANNEL(0);\r
- // 48 MHz / 1024 gives 46.875 kHz\r
- PWM_CH_MODE(0) = PWM_CH_MODE_PRESCALER(10);\r
- PWM_CH_DUTY_CYCLE(0) = 0;\r
- PWM_CH_PERIOD(0) = 0xffff;\r
-\r
- WORD start = (WORD)PWM_CH_COUNTER(0);\r
-\r
- int letoff = 0;\r
- for(;;)\r
- {\r
- WORD now = (WORD)PWM_CH_COUNTER(0);\r
-\r
- // We haven't let off the button yet\r
- if (!letoff)\r
- {\r
- // We just let it off!\r
- if (!BUTTON_PRESS())\r
- {\r
- letoff = 1;\r
-\r
- // reset our timer for 500ms\r
- start = (WORD)PWM_CH_COUNTER(0);\r
- ticks = (48000 * (500)) >> 10;\r
- }\r
-\r
- // Still haven't let it off\r
- else\r
- // Have we held down a full second?\r
- if (now == (WORD)(start + ticks))\r
- return BUTTON_HOLD;\r
- }\r
-\r
- // We already let off, did we click again?\r
- else\r
- // Sweet, double click!\r
- if (BUTTON_PRESS())\r
- return BUTTON_DOUBLE_CLICK;\r
-\r
- // Have we ran out of time to double click?\r
- else\r
- if (now == (WORD)(start + ticks))\r
- // At least we did a single click\r
- return BUTTON_SINGLE_CLICK;\r
-\r
- WDT_HIT();\r
- }\r
-\r
- // We should never get here\r
- return BUTTON_ERROR;\r
-}\r
-\r
-// Determine if a button is held down\r
-int BUTTON_HELD(int ms)\r
-{\r
- // If button is held for one second\r
- int ticks = (48000 * (ms ? ms : 1000)) >> 10;\r
-\r
- // If we're not even pressed, forget about it!\r
- if (!BUTTON_PRESS())\r
- return BUTTON_NO_CLICK;\r
-\r
- // Borrow a PWM unit for my real-time clock\r
- PWM_ENABLE = PWM_CHANNEL(0);\r
- // 48 MHz / 1024 gives 46.875 kHz\r
- PWM_CH_MODE(0) = PWM_CH_MODE_PRESCALER(10);\r
- PWM_CH_DUTY_CYCLE(0) = 0;\r
- PWM_CH_PERIOD(0) = 0xffff;\r
-\r
- WORD start = (WORD)PWM_CH_COUNTER(0);\r
-\r
- for(;;)\r
- {\r
- WORD now = (WORD)PWM_CH_COUNTER(0);\r
-\r
- // As soon as our button let go, we didn't hold long enough\r
- if (!BUTTON_PRESS())\r
- return BUTTON_SINGLE_CLICK;\r
-\r
- // Have we waited the full second?\r
- else\r
- if (now == (WORD)(start + ticks))\r
- return BUTTON_HOLD;\r
-\r
- WDT_HIT();\r
- }\r
-\r
- // We should never get here\r
- return BUTTON_ERROR;\r
-}\r
-\r
-// attempt at high resolution microsecond timer\r
-// beware: timer counts in 21.3uS increments (1024/48Mhz)\r
-void SpinDelayUs(int us)\r
-{\r
- int ticks = (48*us) >> 10;\r
-\r
- // Borrow a PWM unit for my real-time clock\r
- PWM_ENABLE = PWM_CHANNEL(0);\r
- // 48 MHz / 1024 gives 46.875 kHz\r
- PWM_CH_MODE(0) = PWM_CH_MODE_PRESCALER(10);\r
- PWM_CH_DUTY_CYCLE(0) = 0;\r
- PWM_CH_PERIOD(0) = 0xffff;\r
-\r
- WORD start = (WORD)PWM_CH_COUNTER(0);\r
-\r
- for(;;) {\r
- WORD now = (WORD)PWM_CH_COUNTER(0);\r
- if (now == (WORD)(start + ticks))\r
- return;\r
-\r
- WDT_HIT();\r
- }\r
-}\r
-\r
-void SpinDelay(int ms)\r
-{\r
- // convert to uS and call microsecond delay function\r
- SpinDelayUs(ms*1000);\r
-}\r
+//-----------------------------------------------------------------------------
+// Jonathan Westhues, Sept 2005
+//
+// 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.
+//-----------------------------------------------------------------------------
+// Utility functions used in many places, not specific to any piece of code.
+//-----------------------------------------------------------------------------
+
+#include "proxmark3.h"
+#include "util.h"
+#include "string.h"
+#include "apps.h"
+#include "BigBuf.h"
+
+
+
+void print_result(char *name, uint8_t *buf, size_t len) {
+ uint8_t *p = buf;
+
+ if ( len % 16 == 0 ) {
+ for(; p-buf < len; p += 16)
+ Dbprintf("[%s:%d/%d] %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
+ name,
+ p-buf,
+ len,
+ p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]
+ );
+ }
+ else {
+ for(; p-buf < len; p += 8)
+ Dbprintf("[%s:%d/%d] %02x %02x %02x %02x %02x %02x %02x %02x", name, p-buf, len, p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
+ }
+}
+
+size_t nbytes(size_t nbits) {
+ return (nbits >> 3)+((nbits % 8) > 0);
+}
+
+uint32_t SwapBits(uint32_t value, int nrbits) {
+ uint32_t newvalue = 0;
+ for(int i = 0; i < nrbits; i++) {
+ newvalue ^= ((value >> i) & 1) << (nrbits - 1 - i);
+ }
+ return newvalue;
+}
+
+void num_to_bytes(uint64_t n, size_t len, uint8_t* dest)
+{
+ while (len--) {
+ dest[len] = (uint8_t) n;
+ n >>= 8;
+ }
+}
+
+uint64_t bytes_to_num(uint8_t* src, size_t len)
+{
+ uint64_t num = 0;
+ while (len--)
+ {
+ num = (num << 8) | (*src);
+ src++;
+ }
+ return num;
+}
+
+// RotateLeft - Ultralight, Desfire
+void rol(uint8_t *data, const size_t len){
+ uint8_t first = data[0];
+ for (size_t i = 0; i < len-1; i++) {
+ data[i] = data[i+1];
+ }
+ data[len-1] = first;
+}
+
+void lsl (uint8_t *data, size_t len) {
+ for (size_t n = 0; n < len - 1; n++) {
+ data[n] = (data[n] << 1) | (data[n+1] >> 7);
+ }
+ data[len - 1] <<= 1;
+}
+
+int32_t le24toh (uint8_t data[3])
+{
+ return (data[2] << 16) | (data[1] << 8) | data[0];
+}
+
+void LEDsoff()
+{
+ LED_A_OFF();
+ LED_B_OFF();
+ LED_C_OFF();
+ LED_D_OFF();
+}
+
+// LEDs: R(C) O(A) G(B) -- R(D) [1, 2, 4 and 8]
+void LED(int led, int ms)
+{
+ if (led & LED_RED)
+ LED_C_ON();
+ if (led & LED_ORANGE)
+ LED_A_ON();
+ if (led & LED_GREEN)
+ LED_B_ON();
+ if (led & LED_RED2)
+ LED_D_ON();
+
+ if (!ms)
+ return;
+
+ SpinDelay(ms);
+
+ if (led & LED_RED)
+ LED_C_OFF();
+ if (led & LED_ORANGE)
+ LED_A_OFF();
+ if (led & LED_GREEN)
+ LED_B_OFF();
+ if (led & LED_RED2)
+ LED_D_OFF();
+}
+
+
+// Determine if a button is double clicked, single clicked,
+// not clicked, or held down (for ms || 1sec)
+// In general, don't use this function unless you expect a
+// double click, otherwise it will waste 500ms -- use BUTTON_HELD instead
+int BUTTON_CLICKED(int ms)
+{
+ // Up to 500ms in between clicks to mean a double click
+ int ticks = (48000 * (ms ? ms : 1000)) >> 10;
+
+ // If we're not even pressed, forget about it!
+ if (!BUTTON_PRESS())
+ return BUTTON_NO_CLICK;
+
+ // 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;
+
+ int letoff = 0;
+ for(;;)
+ {
+ uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;
+
+ // We haven't let off the button yet
+ if (!letoff)
+ {
+ // We just let it off!
+ if (!BUTTON_PRESS())
+ {
+ letoff = 1;
+
+ // reset our timer for 500ms
+ start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;
+ ticks = (48000 * (500)) >> 10;
+ }
+
+ // Still haven't let it off
+ else
+ // Have we held down a full second?
+ if (now == (uint16_t)(start + ticks))
+ return BUTTON_HOLD;
+ }
+
+ // We already let off, did we click again?
+ else
+ // Sweet, double click!
+ if (BUTTON_PRESS())
+ return BUTTON_DOUBLE_CLICK;
+
+ // Have we ran out of time to double click?
+ else
+ if (now == (uint16_t)(start + ticks))
+ // At least we did a single click
+ return BUTTON_SINGLE_CLICK;
+
+ WDT_HIT();
+ }
+
+ // We should never get here
+ return BUTTON_ERROR;
+}
+
+// Determine if a button is held down
+int BUTTON_HELD(int ms)
+{
+ // If button is held for one second
+ int ticks = (48000 * (ms ? ms : 1000)) >> 10;
+
+ // If we're not even pressed, forget about it!
+ if (!BUTTON_PRESS())
+ return BUTTON_NO_CLICK;
+
+ // 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;
+
+ // As soon as our button let go, we didn't hold long enough
+ if (!BUTTON_PRESS())
+ return BUTTON_SINGLE_CLICK;
+
+ // Have we waited the full second?
+ else
+ if (now == (uint16_t)(start + ticks))
+ return BUTTON_HOLD;
+
+ WDT_HIT();
+ }
+
+ // We should never get here
+ return BUTTON_ERROR;
+}
+
+// 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);
+}
+
+/* Similar to FpgaGatherVersion this formats stored version information
+ * into a string representation. It takes a pointer to the struct version_information,
+ * verifies the magic properties, then stores a formatted string, prefixed by
+ * prefix in dst.
+ */
+void FormatVersionInformation(char *dst, int len, const char *prefix, void *version_information)
+{
+ struct version_information *v = (struct version_information*)version_information;
+ dst[0] = 0;
+ strncat(dst, prefix, len-1);
+ if(v->magic != VERSION_INFORMATION_MAGIC) {
+ strncat(dst, "Missing/Invalid version information\n", len - strlen(dst) - 1);
+ return;
+ }
+ if(v->versionversion != 1) {
+ strncat(dst, "Version information not understood\n", len - strlen(dst) - 1);
+ return;
+ }
+ if(!v->present) {
+ strncat(dst, "Version information not available\n", len - strlen(dst) - 1);
+ return;
+ }
+
+ strncat(dst, v->gitversion, len - strlen(dst) - 1);
+ if(v->clean == 0) {
+ strncat(dst, "-unclean", len - strlen(dst) - 1);
+ } else if(v->clean == 2) {
+ strncat(dst, "-suspect", len - strlen(dst) - 1);
+ }
+
+ strncat(dst, " ", len - strlen(dst) - 1);
+ strncat(dst, v->buildtime, len - strlen(dst) - 1);
+ strncat(dst, "\n", len - strlen(dst) - 1);
+}
+
+// -------------------------------------------------------------------------
+// timer lib
+// -------------------------------------------------------------------------
+// test procedure:
+//
+// ti = GetTickCount();
+// SpinDelay(1000);
+// ti = GetTickCount() - ti;
+// Dbprintf("timer(1s): %d t=%d", ti, GetTickCount());
+
+void StartTickCount()
+{
+ // 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(){
+ return AT91C_BASE_RTTC->RTTC_RTVR;// was * 2;
+}
+
+// -------------------------------------------------------------------------
+// microseconds timer
+// -------------------------------------------------------------------------
+void StartCountUS()
+{
+ AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14);
+// AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC1XC1S_TIOA0;
+ AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
+
+ // fast clock
+ AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
+ AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz)/32 -- tick=1.5mks
+ 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_BASE_TC1->TC_CCR = AT91C_TC_CLKEN;
+ AT91C_BASE_TCB->TCB_BCR = 1;
+ }
+
+uint32_t RAMFUNC GetCountUS(){
+ //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);
+}
+
+static uint32_t GlobalUsCounter = 0;
+
+uint32_t RAMFUNC GetDeltaCountUS(){
+ uint32_t g_cnt = GetCountUS();
+ uint32_t g_res = g_cnt - GlobalUsCounter;
+ GlobalUsCounter = g_cnt;
+ return g_res;
+}
+
+
+// -------------------------------------------------------------------------
+// Timer for iso14443 commands. Uses ssp_clk from FPGA
+// -------------------------------------------------------------------------
+void StartCountSspClk()
+{
+ 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; // enable TC0
+ AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN; // enable TC1
+ AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN; // enable TC2
+
+ //
+ // synchronize the counter with the ssp_frame signal. Note: FPGA must be in any iso14446 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_TC0->TC_CV < 0xFFF0);
+}
+
+uint32_t RAMFUNC GetCountSspClk(){
+ 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;
+}
+