ST25TA02K-D datasheet(12/64 Pages) STMICROELECTRONICS

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Signal descriptions

ST25TA02K-D

12/64

DocID027817 Rev 1

2.3

General Purpose Output (GPO)

The GPO pad is an open drain pad and a external pull-up resistor shall be connected to it.

This pad is a configurable output signal, driven a low level when configured event occurs,

otherwise it remains in an high impedance state. Its behavior is consistent with the RF

session activated and with the mode chosen by the user.

The user can select one of these configurations(a):

•

SessionOpen: an RF session is ongoing.

•

MIP (NDEF Message updating In Progress): the RF host is writing an NDEF length

different from 0x0000. This mode can be used to detect when the RF host changes the

NDEF message as defined by the NFC Forum.

•

WIP (Writing In Progress): the ST25TA02K-D is executing a writing operation.

•

INT (interrupt): the RF host can force the ST25TA02K-D to send an alternate pulse on

the GPO pin.

•

State mode: the RF host can control the state of the GPO pad during the RF session.

•

RF busy: an RF host is communicating with the ST25TA02K-D.

•

Field detection: the RF field is sufficient to establish an RF communication with the

ST25TA02K-D.

GPO configuration byte can be locked, by setting its Most Significant Bit to 1 (1xxx 0000 b).

Once locked, this byte cannot be changed anymore.

a. See Table 59: GPO timings measurement for more details.

ST25TA02K-D Datasheet(PDF) 12 Page - STMicroelectronics