#include "apps.h"
#include "BigBuf.h"
-
-
void print_result(char *name, uint8_t *buf, size_t len) {
uint8_t *p = buf;
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
- //
+ // 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 (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.
+
+ // 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);
}