]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - armsrc/iso14443a.c
revert change "hf list topaz" to "hf list nfc"
[proxmark3-svn] / armsrc / iso14443a.c
index a78dae6eebadfea59dbe3ea26cee4f8e7eef450e..06a134f6b56f519d076295ef15885461ed2c96bc 100644 (file)
@@ -248,8 +248,7 @@ void UartReset()
        Uart.parityLen = 0;                                     // number of decoded parity bytes
        Uart.shiftReg = 0;                                      // shiftreg to hold decoded data bits
        Uart.parityBits = 0;                            // holds 8 parity bits
-       Uart.twoBits = 0x0000;                          // buffer for 2 Bits
-       Uart.highCnt = 0;
+       Uart.fourBits = 0x00000000;                     // buffer for 4 Bits
        Uart.startTime = 0;
        Uart.endTime = 0;
 }
@@ -265,40 +264,34 @@ void UartInit(uint8_t *data, uint8_t *parity)
 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
 {
 
-       Uart.twoBits = (Uart.twoBits << 8) | bit;
+       Uart.fourBits = (Uart.fourBits << 8) | bit;
        
        if (Uart.state == STATE_UNSYNCD) {                                                                                      // not yet synced
        
-               if (Uart.highCnt < 1) {                                                                                                 // wait for a stable unmodulated signal
-                       if (Uart.twoBits == 0xffff) {
-                               Uart.highCnt++;
-                       } else {
-                               Uart.highCnt = 0;
-                       }
-               } else {        
-                       Uart.syncBit = 0xFFFF;                                                                                          // not set
-                                                                                                                                                               // we look for a ...1111111100x11111xxxxxx pattern (the start bit)
-                       if              ((Uart.twoBits & 0xDF00) == 0x1F00) Uart.syncBit = 8;           // mask is   11x11111 xxxxxxxx, 
-                                                                                                                                                               // check for 00x11111 xxxxxxxx
-                       else if ((Uart.twoBits & 0xEF80) == 0x8F80) Uart.syncBit = 7;           // both masks shifted right one bit, left padded with '1'
-                       else if ((Uart.twoBits & 0xF7C0) == 0xC7C0) Uart.syncBit = 6;           // ...
-                       else if ((Uart.twoBits & 0xFBE0) == 0xE3E0) Uart.syncBit = 5;
-                       else if ((Uart.twoBits & 0xFDF0) == 0xF1F0) Uart.syncBit = 4;
-                       else if ((Uart.twoBits & 0xFEF8) == 0xF8F8) Uart.syncBit = 3;
-                       else if ((Uart.twoBits & 0xFF7C) == 0xFC7C) Uart.syncBit = 2;
-                       else if ((Uart.twoBits & 0xFFBE) == 0xFE3E) Uart.syncBit = 1;
-                       if (Uart.syncBit != 0xFFFF) {                                                                           // found a sync bit
-                               Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
-                               Uart.startTime -= Uart.syncBit;
-                               Uart.endTime = Uart.startTime;
-                               Uart.state = STATE_START_OF_COMMUNICATION;
-                       }
+               Uart.syncBit = 9999;                                                                                                    // not set
+               // we look for a ...xxxx1111111100x11111xxxxxx pattern 
+               // (unmodulated, followed by the start bit = 8 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
+#define ISO14443A_STARTBIT_MASK                0x007FEF80                                                                      // mask is    00000000 01111111 11101111 10000000
+#define ISO14443A_STARTBIT_PATTERN     0x007F8F80                                                                      // pattern is 00000000 01111111 10001111 10000000
+               if              ((Uart.fourBits & ISO14443A_STARTBIT_MASK) >> 0 == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
+               else if ((Uart.fourBits & ISO14443A_STARTBIT_MASK) >> 1 == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
+               else if ((Uart.fourBits & ISO14443A_STARTBIT_MASK) >> 2 == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
+               else if ((Uart.fourBits & ISO14443A_STARTBIT_MASK) >> 3 == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
+               else if ((Uart.fourBits & ISO14443A_STARTBIT_MASK) >> 4 == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
+               else if ((Uart.fourBits & ISO14443A_STARTBIT_MASK) >> 5 == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
+               else if ((Uart.fourBits & ISO14443A_STARTBIT_MASK) >> 6 == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
+               else if ((Uart.fourBits & ISO14443A_STARTBIT_MASK) >> 7 == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
+               if (Uart.syncBit != 9999) {                                                                                             // found a sync bit
+                       Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
+                       Uart.startTime -= Uart.syncBit;
+                       Uart.endTime = Uart.startTime;
+                       Uart.state = STATE_START_OF_COMMUNICATION;
                }
 
        } else {
 
-               if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) {                  
-                       if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) {          // Modulation in both halves - error
+               if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {                 
+                       if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation in both halves - error
                                UartReset();
                        } else {                                                                                                                        // Modulation in first half = Sequence Z = logic "0"
                                if (Uart.state == STATE_MILLER_X) {                                                             // error - must not follow after X
@@ -322,7 +315,7 @@ static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
                                }
                        }
                } else {
-                       if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) {          // Modulation second half = Sequence X = logic "1"
+                       if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation second half = Sequence X = logic "1"
                                Uart.bitCount++;
                                Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100;                                   // add a 1 to the shiftreg
                                Uart.state = STATE_MILLER_X;
@@ -358,12 +351,10 @@ static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
                                                return TRUE;                                                                                    // we are finished with decoding the raw data sequence
                                        } else {
                                                UartReset();                                                                                    // Nothing received - start over
-                                               Uart.highCnt = 1;
                                        }
                                }
                                if (Uart.state == STATE_START_OF_COMMUNICATION) {                               // error - must not follow directly after SOC
                                        UartReset();
-                                       Uart.highCnt = 1;
                                } else {                                                                                                                // a logic "0"
                                        Uart.bitCount++;
                                        Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
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