mlx90121 Melexis Company, mlx90121 Datasheet - Page 9

• Manufacturer Part Number: mlx90121
• Description: 13.56mhz Rfid Transceiver
• Manufacturer: Melexis Company

11.
11.1. Definitions
There are two main operating modes:
The configuration mode allows writing in the configuration registers. It will configure all parameters in the
transceiver.
The communication mode allows communicating with a transponder. Different options are available:
11.2. Configuration Mode
Registers Addresses
For configuration purposes, users have access to 13 eight bit registers, which can be addressed using a 4
bit address.
(*) the reserved register is for manufacturing purpose only and should not be used.
Write Configuration Registers
First the MODE line is asserted low to enable the configuration mode. Then data is fed serially into the
chip with the CK and DIN lines. Data on the DIN line is read on the rising edge of CK. The first four bits on
DIN are the register address and the eight following bits are the data. Address and data fields are written
MSB (Most Significant Bit) first.
3901090121
Rev. 007
Operating Modes
MODE = 0
MODE = 1
Direct transmission: The transmission protocol is handled by an external microcontroller.
Hardware transmission: The low level protocol is handled by an internal programmable encoder. It
allows using a low cost microcontroller.
Direct reception: The reception protocol is handled by an external microcontroller.
Hardware reception: FSK/PSK decoders and Majority Voting can be enabled to allow using a low
cost microcontroller.
: Configuration Mode
: Communication Mode
Page 9 of 26
13.56MHz RFID Transceiver
MLX90121
Data Sheet
Jan-2008