SRI512_08 Datasheet, PDF (13/47 Pages) STMicroelectronics – 13.56 MHz short-range contactless memory chip with 512-bit EEPROM and anticollision functions

SRI512
Data transfer
3.4
CRC
The 16-bit CRC used by the SRI512 is generated in compliance with the ISO14443 Type B
recommendation. For further information, please see Appendix A. The initial register
contents are all 1’s: FFFFh.
The two-byte CRC is present in every request and in every answer frame, before the EOF.
The CRC is calculated on all the bytes between SOF (not included) and the CRC field.
Upon reception of a request from a reader, the SRI512 verifies that the CRC value is valid. If
it is invalid, the SRI512 discards the frame and does not answer the reader.
Upon reception of an answer from the SRI512, the reader should verify the validity of the
CRC. In case of error, the actions to be taken are the reader designer’s responsibility.
The CRC is transmitted with the least significant byte first and each byte is transmitted with
the least significant bit first.
Figure 11. CRC transmission rules
LSbit
LSByte
MSbit LSbit
MSByte
MSbit
CRC 16 (8 bits)
CRC 16 (8 bits)
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