MLX90132 Datasheet, PDF (9/44 Pages) Melexis Microelectronic Systems – 13.56MHz RFID / NFC Transceiver

MLX90132
13.56MHz RFID / NFC Transceiver
5 Communication Interface & protocol
Whatever the communication protocol selected (SPI or UART), the principle of communication is always the
same: The application sends a command to the MLX90132 and waits for the appropriate answer. A simple
and specific set of commands allows the configuration and control of the MLX90132.
Application
MLX90132
Select protocol
(e.g. ISO15693, Single Sub-carrier)
→
←
Send protocol related data, CRC automatically
added (e.g. “022000” + CRC)
→
←
Select another protocol
(e.g. ISO14443A, 7-bit mode)
→
←
Send protocol related data, CRC automatically
(e.g. “26”)
→
←
Turn field OFF
→
←
Protocol selected, ready for communicate
Return TAG answer
(e.g. “001234ABCD”, CRC correct)
Protocol selected, ready for communicate
Return TAG answer
(e.g. “0400” , Parity is OK, CRC ignored)
Field is OFF
Figure 5: Example of communication with MLX90132
In order to start RFID communication, the application has to choose the protocol and specify some
parameters, using the command Protocol select command (0x02). When the protocol is selected, the
application sends data and parses response until the next protocol is selected or a specific parameter is
changed.
5.1 UART
The default baud rate is 57.6kbps and the maximum allowed baud rate is 2 Mbps.
Sending command to MLX90132
Receiving answer from MLX90132
Several data bytes
Several data bytes
Figure 6: UART communication
Notes:
 Option “clock recovery” (“ClkRec” in Table 11) should not be used when UART interface is selected.
Therefore the UART mode is not recommended for TAG emulation mode
 Length of data field can be zero, in this case no data is sent.
Warning: The UART communication is least significant bit (LSB) first.
3901090132
Rev. 009
Page 9 of 44
Jan-2014