SR176_07 Datasheet, PDF (10/35 Pages) STMicroelectronics – 13.56 MHz, 176-bit short range contactless user EEPROM with 64-bit Unique ID

Data transfer
SR176
3.6
Character transmission format for answer frames
The character format is the same as for the input data transfer (Figure 4). The transmitted
frames include an SOF, data, a CRC and an EOF (as shown in Figure 10). Like the input
data transfer, in case of error, the reader does not emit any error code to the SR176, but
must be able to detect and manage this situation. The data transfer rate is 106 Kbit/second.
3.7
Answer start of frame
The SOF, as shown in Figure 8, consists of:
● 10 ETUs at logic 0
● 2 ETUs at logic 1
3.8
Answer end of frame
The EOF, as shown in Figure 9, consists of:
● 10 ETUs at logic 0
● 2 ETUs at logic 1
Figure 7. Emitted wave using BPSK subcarrier modulation
Data Bit to Transmit
to the Reader
847.5kHz BPSK Modulation
Generated by the SR176
Or
10/35
BPSK Modulation at 847.5kHz
During One Bit Time (1/106kHz)
AI09059
Figure 8. Answer start of frame
b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 b10 b11
ETU 0
0
0
0
0
0
0
0
0
0
1
1
ai07665
Figure 9. Answer end of frame
b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 b10 b11
ETU 0
0
0
0
0
0
0
0
0
0
1
1
ai07665