SRI4K_11 datasheet(13/46 Pages) STMICROELECTRONICS

No de pièce	SRI4K

Description	13.56 MHz short-range contactless memory chip with 4096-bit EEPROM and anticollision functions

PDF	46 Pages

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Fabricant	STMICROELECTRONICS [STMicroelectronics]

Site Internet	http://www.st.com

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SRI4K

Data transfer

Doc 11605 Rev 5

13/46

3.4

CRC

The 16-bit CRC used by the SRI4K is generated in compliance with the ISO14443 Type B

recommendation. For further information, please see Appendix A. The initial register

contents are all 1s: 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 SRI4K verifies that the CRC value is valid. If

it is invalid, the SRI4K discards the frame and does not answer the reader.

Upon reception of an answer from the SRI4K, 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

CRC 16 (8 bits)

LSbit

MSbit

LSbit

MSbit

LSByte

MSByte

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SRI4K Fiches technique(PDF) 13 Page - STMicroelectronics