AN4433 datasheet(7/34 Pages) STMICROELECTRONICS

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AN4433

Reminder on NFC Forum Type 4 Tag and NDEF data structure

Figure 2. NFC Forum Type 4 Tag memory

1.2

Memory access

An NFC Forum Type 4 Tag can be accessed only through a “file access” interface: no direct

addressing of memory area is possible.

File access allows to:

–

have direct access to a specific area of the memory, without parsing the other part

–

separate the memory areas for different applications/data (with no accidental

overread/overwrite of the memory)

–

give read/write access rights per memory area

To interact with an NFC Forum Type 4 Tag, a reader/writer device must:

–

apply the “Listen, RF Collision Avoidance, Technology Detection, Collision

Resolution” activity for suitable technology (NFC-A technology for M24SRxx-Y

products), as defined in doc [1].

–

perform the “Device Activation” activity for suitable Device Platform (Type 4A Tag

Platform for M24SRxx-Y products), as defined in doc[1].

–

apply the “NDEF Detection Procedure” (and Proprietary files read, if any), as

defined in doc [2]., inside ISODEP protocol (see doc [1].).

For examples of file accesses:

–See Appendix A and Appendix B.

1.3

Reader/Writer behavior in front of NFC Forum Type 4 Tag

NFC is now widely deployed on both common platforms (smartphones and tablets) with

well-known OS (Android™, Windows® Phone 7.5/8.0, BlackBerry® 10), and proprietary

NFC/RFID readers.

NFC Forum Type 4 Tag and NDEF data format offer native interoperability to exchange

standard NDEF data between these devices.

In front of an NFC Forum Type 4 Tag, any reader will natively interpret the standard NDEF

data, and start the application, registered for the data type of the first record of the NDEF

file.

AN4433 Scheda tecnica(PDF) 7 Page - STMicroelectronics