SRT512 datasheet(13/46 Pages) STMICROELECTRONICS

Teilenummer	SRT512

Bauteilbeschribung	13.56 MHz short-range contactless memory chip with 512-bit EEPROM and anticollision functions

PDF	46 Pages

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Hersteller	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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13 / 46 page

SRT512

Data transfer

Doc ID 13277 Rev 4

13/46

3.4

CRC

The 16-bit CRC used by the SRT512 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 SRT512 verifies that the CRC value is valid.

If it is invalid, the SRT512 discards the frame and does not answer the reader.

Upon reception of an answer from the SRT512, 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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SRT512 Datenblatt(PDF) 13 Page - STMicroelectronics