X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/41863885d0b03223205c2dfc8d87743a100abf28..b82c2f85e457f361b119d21a31f3263ac3489cc8:/armsrc/util.c diff --git a/armsrc/util.c b/armsrc/util.c index 640809e0..120e7b44 100644 --- a/armsrc/util.c +++ b/armsrc/util.c @@ -14,8 +14,6 @@ #include "apps.h" #include "BigBuf.h" - - void print_result(char *name, uint8_t *buf, size_t len) { uint8_t *p = buf; @@ -400,17 +398,17 @@ void StartCountSspClk() 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) @@ -418,8 +416,9 @@ void StartCountSspClk() // 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); }