RFID library

AN2399

14/22

8

RFID library

RFID library is developed using a 4-layer architecture. This section provides a brief

description of the layer functionality.

Figure 6.

RFID library: the 4 layer structure

8.1

RFID reader/writer: the application layer

The RFID EEPROM memory may be accessed directly using the application layer. It allows

read/write operations on RFID EEPROM with different access options. Moreover, the

application layer implements the Finite State Machine (FSM) which allows each device to be

searched for and selected close to the antenna reader.

/*------------------------------------------------------------------

RFID Application Layer

------------------------------------------------------------------

Input:

- RFID_Action: 3 bit

bit 0: 1=ENABLE 64UID request, 0=DISABLE 64UID request

bit 1: 1=ENABLE READ

request, 0=DISABLE READ

request

bit 2: 1=ENABLE WRITE request, 0=DISABLE WRITE request

- TX_frame:

TX buffer pointer (write operations)

- TX_lenght:

TX buffer lenght (write operations)

- TX_offset:

TX offset for write operations

- RX_frame:

RX buffer pointer (read operations)

- RX_lenght:

RX buffer lenght (read operations)

- RX_offset:

RX offset for read operations

- RFID_UID:

64 bits RFID UID

- RFID_timeout: timeout for RFID polling (number of times STR7 is trying to search

tag)

Output:

- RX_frame:

RX buffer pointer (read operations)

- RFID_UID:

64 bits RFID UID

Return:

- Status:

Application layer: applications dedicated

functions

RF Commands layer: Initiate(), Select(),

Completion(), GetUID(), Read_Block(), Write_Block()

Transceiver Commands layer: CRX14 registers

management

RFID reader/writer

SR176 Commands

CRX14 Commands

STR710

CRX14

Tag

I2C

RF - ASK Mod

RF-BPSK mod

Firmware specifications

RFID firmware for STR710 supports SR176 tag

Firmware is developed on a 4 layer structure: