X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/1cb9b2a3cff3a9281c962356bc79e12c63699920..ed28bbe5ae5ef5ac83c838fcc7354b349644f9fe:/armsrc/iso14443b.c

diff --git a/armsrc/iso14443b.c b/armsrc/iso14443b.c
index 5d506c3b..ed035d3a 100644
--- a/armsrc/iso14443b.c
+++ b/armsrc/iso14443b.c
@@ -216,16 +216,19 @@ static void CodeIso14443bAsTag(const uint8_t *cmd, int len) {
 	*  -TO VERIFY THIS BELOW-
 	* The mode FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK which we use to simulate tag
 	* works like this:  
-	* - A 1-bit input to the FPGA becomes 8 pulses at 847.5kHz (9.44µS)
-	* - A 0-bit input to the FPGA becomes an unmodulated time of 9.44µS
-	*
+	* - A 1-bit input to the FPGA becomes 8 pulses at 847.5kHz (1.18µS / pulse) == 9.44us
+	* - A 0-bit input to the FPGA becomes an unmodulated time of 1.18µS  or does it become 8 nonpulses for 9.44us
 	*
+	* FPGA doesn't seem to work with ETU.  It seems to work with pulse / duration instead.
 	* 
 	* Card sends data ub 847.e kHz subcarrier
-	* 848k = 9.44µS  = 128 fc
-	* 424k = 18.88µS = 256 fc
-	* 212k = 37.76µS = 512 fc
-	* 106k = 75.52µS = 1024 fc
+	* subcar |duration| FC division
+	* -------+--------+------------
+	* 106kHz | 9.44µS | FC/128
+	* 212kHz | 4.72µS | FC/64
+	* 424kHz | 2.36µS | FC/32
+	* 848kHz | 1.18µS | FC/16
+	* -------+--------+------------
 	*
 	*  Reader data transmission:
 	*   - no modulation ONES
@@ -453,7 +456,7 @@ static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len) {
 		
 	StartCountSspClk();
 	
-	volatile uint8_t b;
+	volatile uint8_t b = 0;
 
 	// clear receiving shift register and holding register
 	// What does this loop do? Is it TR1?
@@ -467,7 +470,6 @@ static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len) {
 	// Now run a `software UART' on the stream of incoming samples.
 	UartInit(received);
 
-	b = 0;
 	uint8_t mask;
 	while( !BUTTON_PRESS() ) {
 		WDT_HIT();
@@ -490,15 +492,14 @@ void ClearFpgaShiftingRegisters(void){
 	volatile uint8_t b;
 
 	// clear receiving shift register and holding register
-	while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+	while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)) {};
 
 	b = AT91C_BASE_SSC->SSC_RHR; (void) b;
 
-	while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+	while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)) {};
 
 	b = AT91C_BASE_SSC->SSC_RHR; (void) b;
-	
-		
+			
 	// wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
 	for (uint8_t j = 0; j < 5; j++) {	// allow timeout - better late than never
 		while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));