+// -------------------------------------------------------------------------
+// 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 ... 13,56MHz/4)
+ | 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 = 0x02; // RC Compare value = 0x02
+
+ // 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 a FPGA mode with SSC transfer, otherwise SSC_FRAME and SSC_CLK signals 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 < 0xFFFF);
+ // Note: needs one more SSP_CLK cycle (1.18 us) until TC2 resets. Don't call GetCountSspClk() that soon.
+}
+
+
+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 GetCountSspClk(){
+ uint32_t hi, lo;
+
+ do {
+ hi = AT91C_BASE_TC2->TC_CV;
+ lo = AT91C_BASE_TC0->TC_CV;
+ } while(hi != AT91C_BASE_TC2->TC_CV);
+
+ return (hi << 16) | lo;
+}
+
+
+// -------------------------------------------------------------------------
+// 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 );
+}
+
+
+// Starts Clock and waits until its reset
+void ResetTicks(void){
+ AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
+ AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
+ while (AT91C_BASE_TC0->TC_CV > 0);
+}
+
+
+void ResetTimer(AT91PS_TC timer){
+ timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
+ while(timer->TC_CV > 0) ;
+}
+
+
+// stop clock
+void StopTicks(void){
+ AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
+ AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
+}
+
+
+static uint64_t next_random = 1;
+
+/* Generates a (non-cryptographically secure) 32-bit random number.
+ *
+ * We don't have an implementation of the "rand" function or a clock to seed it
+ * with, so we just call GetTickCount the first time to seed ourselves.
+ */
+uint32_t prand() {
+ if (next_random == 1) {
+ next_random = GetTickCount();
+ }
+
+ next_random = next_random * 6364136223846793005 + 1;
+ return (uint32_t)(next_random >> 32) % 0xffffffff;
+}
projects / proxmark3-svn / blobdiff