M24SR View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

M24SR

Dynamic NFC/RFID tag IC with 2-Kbit EEPROM, NFC Forum Type 4 Tag and I²C interface

STMicroelectronics 

M24SR02-Y

4

Communication mechanism

Communication mechanism

This chapter describes the principle of communication between an RF or an I2C host and

the M24SR02-Y device.

4.1

Master and slave

The M24SR02-Y acts as a slave device on either the I2C-bus or the RF channel and

therefore waits for a command from the I2C master or the RF host before sending its

response.

The RF host shall generate the RF field and the RF commands.

The I2C host shall supply the M24SR02-Y through the VCC pin and shall generate the I2C

clock on the SCL pad.

4.2

4.2.1

4.2.2

M24SR02-Y session mechanism

The M24SR02-Y is a dynamic NFC/RFID tag which can be accessed either from the RF or

I2C interface. The M24SR02-Y implements a token system. This token has two possible

values, RF or I2C. When the token exists and is assigned to one interface (RF or I2C), the

M24SR02-Y cannot communicate with the other host.

RF token

The token is given to the RF interface once the anticollision is done. The release condition

can be either an RF field cut-off, or the reception of the command deselect, or when the I²C

host sends the KillRFsession.

I2C token

The token is given to the I2C interface when the I2C host has sent the correct device Select.

The release condition can be either a

I2C token release sequence from the

pI2oCwheor sdto, wafntecrownhdiitcihonMo2n4VSCRC02p-inY

or the reception of

goes in Standby

a

power mode.

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