ST25TA64K datasheet(21/45 Pages) STMICROELECTRONICS

21 / 45 page

DocID027764 Rev 1

21/45

ST25TA64K

RF command sets

5.4

S-Block format

The S-Block is used to exchange control information between a reader and a contactless

tag.

There are two requests using the S-Block format:

•

S(DES): the deselect command

•

S(WTX): the Waiting Frame eXtension command or response.

Note:

After receiving the deselect command, the session is released and ST25TA64K enters the

Standby power mode.

In response to a RATS command, ST25TA64K returns FWI parameter (default frame waiting

time used); when ST25TA64K needs more time for a command execution, it requests a

frame waiting time extension by responding 0xF2 0xWTX (Request waiting time = FWI *

WTX). If the reader accepts ST25TA64K request, it acknowledges by sending the command

0xF2 0xWTX. The frame waiting time becomes FWI * WTX for the current command only.

Table 15. S-Block format

NFC frame

SoD

EoD

PCB

DID

Payload

CRC

Length

1 byte

1 to 255 bytes

2 bytes

0xC2: for S(DES) when the DID field is not present

0xCA: for S(DES) when the DID field is present

0xF2: for S(WTX) when the DID field is not present

0xFA: for S(WTX) when the DID field is present

DID field (optional)

WTX field (1)

2 CRC bytes

1. This field is present when b5-b4 bits are set to 0b11 (S-Block is a WTX). see Table 16: S-Block detailed format.

Table 16. S-Block detailed format

b7-b6

b5-b4

0b11

S-Block

0b00: Deselect

0b11: WTX

0: DID field is not present

1: DID field is present

RFU

ST25TA64K Datasheet(PDF) 21 Page - STMicroelectronics

ST25TA64K Datasheet(HTML) 21 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

Datasheet Download

Link URL