+
+//====================================================================
+// prepares address bits
+// see EM4469 spec
+//====================================================================
+
+//--------------------------------------------------------------------
+uint8_t Prepare_Addr( uint8_t addr ) {
+ //--------------------------------------------------------------------
+
+ register uint8_t line_parity;
+
+ uint8_t i;
+ line_parity = 0;
+ for(i=0;i<6;i++) {
+ *forward_ptr++ = addr;
+ line_parity ^= addr;
+ addr >>= 1;
+ }
+
+ *forward_ptr++ = (line_parity & 1);
+
+ return 7; //return number of emited bits
+}
+
+//====================================================================
+// prepares data bits intreleaved with parity bits
+// see EM4469 spec
+//====================================================================
+
+//--------------------------------------------------------------------
+uint8_t Prepare_Data( uint16_t data_low, uint16_t data_hi) {
+ //--------------------------------------------------------------------
+
+ register uint8_t line_parity;
+ register uint8_t column_parity;
+ register uint8_t i, j;
+ register uint16_t data;
+
+ data = data_low;
+ column_parity = 0;
+
+ for(i=0; i<4; i++) {
+ line_parity = 0;
+ for(j=0; j<8; j++) {
+ line_parity ^= data;
+ column_parity ^= (data & 1) << j;
+ *forward_ptr++ = data;
+ data >>= 1;
+ }
+ *forward_ptr++ = line_parity;
+ if(i == 1)
+ data = data_hi;
+ }
+
+ for(j=0; j<8; j++) {
+ *forward_ptr++ = column_parity;
+ column_parity >>= 1;
+ }
+ *forward_ptr = 0;
+
+ return 45; //return number of emited bits
+}
+
+//====================================================================
+// Forward Link send function
+// Requires: forwarLink_data filled with valid bits (1 bit per byte)
+// fwd_bit_count set with number of bits to be sent
+//====================================================================
+void SendForward(uint8_t fwd_bit_count) {
+
+ fwd_write_ptr = forwardLink_data;
+ fwd_bit_sz = fwd_bit_count;
+
+ LED_D_ON();
+
+ //Field on
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+ // Give it a bit of time for the resonant antenna to settle.
+ // And for the tag to fully power up
+ SpinDelay(150);
+
+ // force 1st mod pulse (start gap must be longer for 4305)
+ fwd_bit_sz--; //prepare next bit modulation
+ fwd_write_ptr++;
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+ SpinDelayUs(55*8); //55 cycles off (8us each)for 4305
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
+ SpinDelayUs(16*8); //16 cycles on (8us each)
+
+ // now start writting
+ while(fwd_bit_sz-- > 0) { //prepare next bit modulation
+ if(((*fwd_write_ptr++) & 1) == 1)
+ SpinDelayUs(32*8); //32 cycles at 125Khz (8us each)
+ else {
+ //These timings work for 4469/4269/4305 (with the 55*8 above)
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+ SpinDelayUs(23*8); //16-4 cycles off (8us each)
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
+ SpinDelayUs(9*8); //16 cycles on (8us each)
+ }
+ }
+}
+
+void EM4xLogin(uint32_t Password) {
+
+ uint8_t fwd_bit_count;
+
+ forward_ptr = forwardLink_data;
+ fwd_bit_count = Prepare_Cmd( FWD_CMD_LOGIN );
+ fwd_bit_count += Prepare_Data( Password&0xFFFF, Password>>16 );
+
+ SendForward(fwd_bit_count);
+
+ //Wait for command to complete
+ SpinDelay(20);
+
+}
+
+void EM4xReadWord(uint8_t Address, uint32_t Pwd, uint8_t PwdMode) {
+
+ uint8_t *dest = BigBuf_get_addr();
+ uint16_t bufferlength = BigBuf_max_traceLen();
+ uint32_t i = 0;
+
+ // Clear destination buffer before sending the command 0x80 = average.
+ memset(dest, 0x80, bufferlength);
+
+ uint8_t fwd_bit_count;
+
+ //If password mode do login
+ if (PwdMode == 1) EM4xLogin(Pwd);
+
+ forward_ptr = forwardLink_data;
+ fwd_bit_count = Prepare_Cmd( FWD_CMD_READ );
+ fwd_bit_count += Prepare_Addr( Address );
+
+ // Connect the A/D to the peak-detected low-frequency path.
+ SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+ // Now set up the SSC to get the ADC samples that are now streaming at us.
+ FpgaSetupSsc();
+
+ SendForward(fwd_bit_count);
+
+ // Now do the acquisition
+ i = 0;
+ for(;;) {
+ if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
+ AT91C_BASE_SSC->SSC_THR = 0x43;
+ }
+ if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
+ dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+ ++i;
+ if (i >= bufferlength) break;
+ }
+ }
+
+ cmd_send(CMD_ACK,0,0,0,0,0);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+ LED_D_OFF();
+}
+
+void EM4xWriteWord(uint32_t Data, uint8_t Address, uint32_t Pwd, uint8_t PwdMode) {
+
+ uint8_t fwd_bit_count;
+
+ //If password mode do login
+ if (PwdMode == 1) EM4xLogin(Pwd);
+
+ forward_ptr = forwardLink_data;
+ fwd_bit_count = Prepare_Cmd( FWD_CMD_WRITE );
+ fwd_bit_count += Prepare_Addr( Address );
+ fwd_bit_count += Prepare_Data( Data&0xFFFF, Data>>16 );
+
+ SendForward(fwd_bit_count);
+
+ //Wait for write to complete
+ SpinDelay(20);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+ LED_D_OFF();
+}
+void CopyViKingtoT55x7(uint32_t block1,uint32_t block2)
+{
+ LED_D_ON();
+ T55xxWriteBlock(block1,1,0,0);
+ T55xxWriteBlock(block2,2,0,0);
+
+ T55xxWriteBlock(T55x7_MODULATION_MANCHESTER | T55x7_BITRATE_RF_32 | 2 << T5555_MAXBLOCK_SHIFT,0,0,1);
+ LED_D_OFF();
+ DbpString("DONE!");
+}
+
+
+#define T0_PCF 8 //period for the pcf7931 in us
+
+/* Write on a byte of a PCF7931 tag
+ * @param address : address of the block to write
+ @param byte : address of the byte to write
+ @param data : data to write
+ */
+void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, uint8_t pass5, uint8_t pass6, uint8_t pass7, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data)
+{
+
+ uint32_t tab[1024]={0}; // data times frame
+ uint32_t u = 0;
+ uint8_t parity = 0;
+ bool comp = 0;
+
+
+ //BUILD OF THE DATA FRAME
+
+ //alimentation of the tag (time for initializing)
+ AddPatternPCF7931(init_delay, 0, 8192/2*T0_PCF, tab);
+
+ //PMC
+ Dbprintf("Initialization delay : %d us", init_delay);
+ AddPatternPCF7931(8192/2*T0_PCF + 319*T0_PCF+70, 3*T0_PCF, 29*T0_PCF, tab);
+
+ Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);
+
+ //password indication bit
+ AddBitPCF7931(1, tab, l, p);
+
+
+ //password (on 56 bits)
+ Dbprintf("Password (LSB first on each byte) : %02x %02x %02x %02x %02x %02x %02x", pass1,pass2,pass3,pass4,pass5,pass6,pass7);
+ AddBytePCF7931(pass1, tab, l, p);
+ AddBytePCF7931(pass2, tab, l, p);
+ AddBytePCF7931(pass3, tab, l, p);
+ AddBytePCF7931(pass4, tab, l, p);
+ AddBytePCF7931(pass5, tab, l, p);
+ AddBytePCF7931(pass6, tab, l, p);
+ AddBytePCF7931(pass7, tab, l, p);
+
+
+ //programming mode (0 or 1)
+ AddBitPCF7931(0, tab, l, p);
+
+ //block adress on 6 bits
+ Dbprintf("Block address : %02x", address);
+ for (u=0; u<6; u++)
+ {
+ if (address&(1<<u)) { // bit 1
+ parity++;
+ AddBitPCF7931(1, tab, l, p);
+ } else{ // bit 0
+ AddBitPCF7931(0, tab, l, p);
+ }
+ }
+
+ //byte address on 4 bits
+ Dbprintf("Byte address : %02x", byte);
+ for (u=0; u<4; u++)
+ {
+ if (byte&(1<<u)) { // bit 1
+ parity++;
+ AddBitPCF7931(1, tab, l, p);
+ } else{ // bit 0
+ AddBitPCF7931(0, tab, l, p);
+ }
+ }
+
+ //data on 8 bits
+ Dbprintf("Data : %02x", data);
+ for (u=0; u<8; u++)
+ {
+ if (data&(1<<u)) { // bit 1
+ parity++;
+ AddBitPCF7931(1, tab, l, p);
+ } else{ //bit 0
+ AddBitPCF7931(0, tab, l, p);
+ }
+ }
+
+
+ //parity bit
+ if((parity%2)==0){
+ AddBitPCF7931(0, tab, l, p); //even parity
+ }else{
+ AddBitPCF7931(1, tab, l, p);//odd parity
+ }
+
+ //time access memory
+ AddPatternPCF7931(5120+2680, 0, 0, tab);
+
+ //conversion of the scale time
+ for(u=0;u<500;u++){
+ tab[u]=(tab[u] * 3)/2;
+ }
+
+
+ //compennsation of the counter reload
+ while (!comp){
+ comp = 1;
+ for(u=0;tab[u]!=0;u++){
+ if(tab[u] > 0xFFFF){
+ tab[u] -= 0xFFFF;
+ comp = 0;
+ }
+ }
+ }
+
+ SendCmdPCF7931(tab);
+}
+
+
+
+/* Send a trame to a PCF7931 tags
+ * @param tab : array of the data frame
+ */
+
+void SendCmdPCF7931(uint32_t * tab){
+ uint16_t u=0;
+ uint16_t tempo=0;
+
+ Dbprintf("SENDING DATA FRAME...");
+
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );
+
+ LED_A_ON();
+
+ // steal this pin from the SSP and use it to control the modulation
+ AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
+ AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
+
+ //initialization of the timer
+ AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14);
+ AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
+ AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
+ AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK; //clock at 48/32 MHz
+ AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
+ AT91C_BASE_TCB->TCB_BCR = 1;
+
+
+ tempo = AT91C_BASE_TC0->TC_CV;
+ for(u=0;tab[u]!= 0;u+=3){
+
+
+ // modulate antenna
+ HIGH(GPIO_SSC_DOUT);
+ while(tempo != tab[u]){
+ tempo = AT91C_BASE_TC0->TC_CV;
+ }
+
+ // stop modulating antenna
+ LOW(GPIO_SSC_DOUT);
+ while(tempo != tab[u+1]){
+ tempo = AT91C_BASE_TC0->TC_CV;
+ }
+
+
+ // modulate antenna
+ HIGH(GPIO_SSC_DOUT);
+ while(tempo != tab[u+2]){
+ tempo = AT91C_BASE_TC0->TC_CV;
+ }
+
+
+ }
+
+ LED_A_OFF();
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+ SpinDelay(200);
+
+
+ AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
+ DbpString("FINISH !");
+ DbpString("(Could be usefull to send the same trame many times)");
+ LED(0xFFFF, 1000);
+}
+
+
+/* Add a byte for building the data frame of PCF7931 tags
+ * @param b : byte to add
+ * @param tab : array of the data frame
+ * @param l : offset on low pulse width
+ * @param p : offset on low pulse positioning
+ */
+
+bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){
+
+ uint32_t u;
+ for (u=0; u<8; u++)
+ {
+ if (byte&(1<<u)) { //bit à 1
+ if(AddBitPCF7931(1, tab, l, p)==1)return 1;
+ } else { //bit à 0
+ if(AddBitPCF7931(0, tab, l, p)==1)return 1;
+ }
+ }
+
+ return 0;
+}
+
+/* Add a bits for building the data frame of PCF7931 tags
+ * @param b : bit to add
+ * @param tab : array of the data frame
+ * @param l : offset on low pulse width
+ * @param p : offset on low pulse positioning
+ */
+bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p){
+ uint8_t u = 0;
+
+ for(u=0;tab[u]!=0;u+=3){} //we put the cursor at the last value of the array
+
+
+ if(b==1){ //add a bit 1
+ if(u==0) tab[u] = 34*T0_PCF+p;
+ else tab[u] = 34*T0_PCF+tab[u-1]+p;
+
+ tab[u+1] = 6*T0_PCF+tab[u]+l;
+ tab[u+2] = 88*T0_PCF+tab[u+1]-l-p;
+ return 0;
+ }else{ //add a bit 0
+
+ if(u==0) tab[u] = 98*T0_PCF+p;
+ else tab[u] = 98*T0_PCF+tab[u-1]+p;
+
+ tab[u+1] = 6*T0_PCF+tab[u]+l;
+ tab[u+2] = 24*T0_PCF+tab[u+1]-l-p;
+ return 0;
+ }
+
+
+ return 1;
+}
+
+/* Add a custom pattern in the data frame
+ * @param a : delay of the first high pulse
+ * @param b : delay of the low pulse
+ * @param c : delay of the last high pulse
+ * @param tab : array of the data frame
+ */
+bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab){
+ uint32_t u = 0;
+ for(u=0;tab[u]!=0;u+=3){} //we put the cursor at the last value of the array
+
+ if(u==0) tab[u] = a;
+ else tab[u] = a + tab[u-1];
+
+ tab[u+1] = b+tab[u];
+ tab[u+2] = c+tab[u+1];
+
+ return 0;
+}
\ No newline at end of file