Rainbow-electronics MAX66140 Manual do Utilizador descarregar pdf (Página 5)

ISO 15693 Communication

Concept

The communication between master and MAX66140

(slave) is based on the exchange of data packets. The

master initiates every transaction; only one side (master

or slaves) transmits information at any time. Each data

packet begins with a start-of-frame (SOF) pattern and

ends with an end-of-frame (EOF) pattern. A data packet

with at least 3 bytes between SOF and EOF is called a

frame (Figure 5). The last 2 bytes of an ISO 15693

frame are an inverted 16-bit CRC of the preceding data

generated according to the CRC-16-CCITT polynomial.

This CRC is transmitted with the LSB first. For more

details on the CRC-16-CCITT, refer to ISO 15693 Part 3,

Annex C.

For transmission, the frame information is modulated on

a carrier frequency, which in the case of ISO 15693 is

13.56MHz. The subsequent paragraphs are a concise

description of the required modulation and coding. For

MAX66140

ISO 15693-Compliant Secure Memory

_______________________________________________________________________________________ 7

SOF 1 OR MORE DATA BYTES CRC (LSB) CRC (MSB) EOF

TIME

Figure 5. ISO 15693 Frame Format

ABRIDGED DATA SHEET

1 2 3 4 5 6 7 8 9 10 ... 20 21

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