mlx90121 Melexis Company, mlx90121 Datasheet - Page 13

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

ISO Examples
Symbol Transmission
CK and DIN inputs are used to transmit symbols. On each rising edge of the CK signal, DIN is sampled to
encode the address of the corresponding symbol. This means that each address of the seven available
symbols can be encoded with a maximum of three bits (meaning three CK pulses). To reduce the usage
of the microcontroller for fast protocol, Sym0 and Sym1 can be transmitted with only one bit and, Sym2
and Sym3 with two bits, as shown in the following table.
(*) Symbol 6 is hard coded to 0xFF (11111111).
To initiate a transmission, it is necessary to send the first symbol with three CK pulses to initialize the
communication. On every rising edge of DSYNC, the following symbol is sent. To complete the
transmission, no more CK pulse should be sent after EOF symbol.
3901090121
Rev. 007
Modulation
DSYNC
DIN
CK
3 CK pulses are mandatory
to start transmission
Sym2
Sym0
Sym2
Page 13 of 26
N e x t m o d u l a t i o n d a t a
available after the rising
edge of DSYNC
Sym0
Sym3
13.56MHz RFID Transceiver
Sym3
Sym5
MLX90121
Sym5
No CK pulse to complete
the transmission
Data Sheet
Jan-2008