-int timestamp;
-
-/* Handle (whether to respond) a frame in tag mode */
-static void frame_handle_tag(struct legic_frame const * const f)
-{
- /* First Part of Handshake (IV) */
- if(f->bits == 7) {
- if(f->data == SESSION_IV) {
- LED_C_ON();
- prng_timer->TC_CCR = AT91C_TC_SWTRG;
- legic_prng_init(f->data);
- frame_send_tag(0x3d, 6, 1); /* 0x3d^0x26 = 0x1b */
- legic_state = STATE_IV;
- legic_read_count = 0;
- legic_prng_bc = 0;
- legic_prng_iv = f->data;
-
- /* TIMEOUT */
- timer->TC_CCR = AT91C_TC_SWTRG;
- while(timer->TC_CV > 1);
- while(timer->TC_CV < 280);
- return;
- } else if((prng_timer->TC_CV % 50) > 40) {
- legic_prng_init(f->data);
- frame_send_tag(0x3d, 6, 1);
- SpinDelay(20);
- return;
- }
- }
-
- /* 0x19==??? */
- if(legic_state == STATE_IV) {
- if((f->bits == 6) && (f->data == (0x19 ^ get_key_stream(1, 6)))) {
- legic_state = STATE_CON;
-
- /* TIMEOUT */
- timer->TC_CCR = AT91C_TC_SWTRG;
- while(timer->TC_CV > 1);
- while(timer->TC_CV < 200);
- return;
- } else {
- legic_state = STATE_DISCON;
- LED_C_OFF();
- Dbprintf("0x19 - Frame: %03.3x", f->data);
- return;
- }
- }
-
- /* Read */
- if(f->bits == 11) {
- if(legic_state == STATE_CON) {
- int key = get_key_stream(-1, 11); //legic_phase_drift, 11);
- int addr = f->data ^ key; addr = addr >> 1;
- int data = ((uint8_t*)BigBuf)[addr];
- int hash = LegicCRC(addr, data, 11) << 8;
- ((uint8_t*)BigBuf)[OFFSET_LOG+legic_read_count] = (uint8_t)addr;
- legic_read_count++;
-
- //Dbprintf("Data:%03.3x, key:%03.3x, addr: %03.3x, read_c:%u", f->data, key, addr, read_c);
- legic_prng_forward(legic_reqresp_drift);
-
- frame_send_tag(hash | data, 12, 1);
-
- /* SHORT TIMEOUT */
- timer->TC_CCR = AT91C_TC_SWTRG;
- while(timer->TC_CV > 1);
- legic_prng_forward(legic_frame_drift);
- while(timer->TC_CV < 180);
- return;
- }
- }
-
- /* Write */
- if(f->bits == 23) {
- int key = get_key_stream(-1, 23); //legic_frame_drift, 23);
- int addr = f->data ^ key; addr = addr >> 1; addr = addr & 0x3ff;
- int data = f->data ^ key; data = data >> 11; data = data & 0xff;
-
- /* write command */
- legic_state = STATE_DISCON;
- LED_C_OFF();
- Dbprintf("write - addr: %x, data: %x", addr, data);
- return;
- }
-
- if(legic_state != STATE_DISCON) {
- Dbprintf("Unexpected: sz:%u, Data:%03.3x, State:%u, Count:%u", f->bits, f->data, legic_state, legic_read_count);
- int i;
- Dbprintf("IV: %03.3x", legic_prng_iv);
- for(i = 0; i<legic_read_count; i++) {
- Dbprintf("Read Nb: %u, Addr: %u", i, ((uint8_t*)BigBuf)[OFFSET_LOG+i]);
- }
-
- for(i = -1; i<legic_read_count; i++) {
- uint32_t t;
- t = ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4];
- t |= ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4+1] << 8;
- t |= ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4+2] <<16;
- t |= ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4+3] <<24;
-
- Dbprintf("Cycles: %u, Frame Length: %u, Time: %u",
- ((uint8_t*)BigBuf)[OFFSET_LOG+128+i],
- ((uint8_t*)BigBuf)[OFFSET_LOG+384+i],
- t);
- }
- }
- legic_state = STATE_DISCON;
- legic_read_count = 0;
- SpinDelay(10);
- LED_C_OFF();
- return;