+
+
+// -------------------------------------------------------------------------
+// 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