CR14 datasheet(29/46 Pages) STMICROELECTRONICS

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CR14

6 CR14 ISO14443 type-B Radio Frequency data transfer

29/46

6.6

Transmission Format of Answer Frame Characters

The PICC should use the same character format as that used for output data transfer (see

Figure 20).

An Answer Frame includes the SOF, data, CRC and the EOF, as illustrated in Figure 26. The

data transfer rate is 106 kbit/s.

The CR14 will also accept Answer Frames that do not contain the SOF and EOF delimiters,

provided that these Frames are correctly set in the Parameter Register. (See Figure 26).

6.7

Answer Start Of Frame

The PICC SOF must be compliant with the ISO14443 type-B, and is shown in Figure 24

●

Ten or eleven Elementary Time Units (ETU) each containing a logical ‘0’,

●

Two ETUs containing a logical ‘1’.

Figure 24. Answer Start Of Frame

6.8

Answer End Of Frame

The PICC EOF must be compliant with the ISO14443 type-B, and is shown in Figure 25:

●

Ten or eleven Elementary Time Units (ETU) each containing a logical ‘0’,

●

Two ETUs containing a logical ‘1’

Figure 25. Answer End Of Frame

b10

b11

ETU

000000000011

ai09254

b12

b10

b11

ETU

000000000011

ai09254

b12

CR14 Datasheet(PDF) 29 Page - STMicroelectronics