Rainbow Electronics AT88RF1354 - Manual (Page 28)

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13.56 MHz Type B RF Reader
8547A −RFID−10/08
A.3. Frame Format
Data transmitted by the PCD or PICC is sent as frames. The frame consists of the start of frame (SOF), several
bytes of information, and the end of frame (EOF). The SOF and EOF requirements are shown in Figure A-2.
Figure A-2. Start of Frame (SOF) and End of Frame (EOF) format requirement
Start of Frame
10 to 11 ETUs of "0"s
10 to 11 ETUs of "0"s
Total start of frame length is 12 to 14 ETUs.
Total end of frame length is 10 to 11 ETUs.
2 to 3 ETUs "1"s
Start b0 b1
First Byte
Last Byte
End of Frame
A.4. Reader Data Transmission
The unmodulated 13.56 Mhz carrier signal amplitude which is transmitted when the reader is idle is defined as logical
“1”, while the modulated signal level is defined as logical “0”. A frame transmitted by the reader consists of SOF,
several bytes of data, a 2 byte CRC_B, and the EOF.
Figure A-3. Format of a frame transmitted by the reader to the card.
SOF
No Modulation ("1"s) No Modulation ("1"s) Command, Data, and CRC_B
Data Transmission EOF