NTAG213F/216F
NXP Semiconductors
NFC Forum T2T IC with 144/888 bytes user memory and field detection
8.4.1 IDLE state
After a power-on reset (POR), NTAG21xF switches to the IDLE state. It only exits this
state when a REQA or a WUPA command is received from the NFC device. Any other
data received while in this state is interpreted as an error and NTAG21xF remains in the
IDLE state.
After a correctly executed HLTA command i.e. out of the ACTIVE or AUTHENTICATED
state, the default waiting state changes from the IDLE state to the HALT state. This state
can then be exited with a WUPA command only.
8.4.2 READY1 state
In this state, the NFC device resolves the first part of the UID (3 bytes) using the
ANTICOLLISION or SELECT commands in cascade level 1. This state is correctly exited
after execution of either of the following commands:
• SELECT command from cascade level 1: the NFC device switches NTAG21xF into
READY2 state where the second part of the UID is resolved.
• READ command (from address 0): all anticollision mechanisms are bypassed and the
NTAG21xF switches directly to the ACTIVE state.
Remark: If more than one NTAG is in the NFC device field, a READ command from
address 0 selects all NTAG21xF devices. In this case, a collision occurs due to different
serial numbers. Any other data received in the READY1 state is interpreted as an error
and depending on its previous state NTAG21xF returns to the IDLE or HALT state.
8.4.3 READY2 state
In this state, NTAG21xF supports the NFC device in resolving the second part of its UID
(4 bytes) with the cascade level 2 ANTICOLLISION command. This state is usually exited
using the cascade level 2 SELECT command.
Alternatively, READY2 state can be skipped using a READ command (from address 0) as
described for the READY1 state.
Remark: The response of NTAG21xF to the cascade level 2 SELECT command is the
Select AcKnowledge (SAK) byte. In accordance with ISO/IEC 14443, this byte indicates if
the anticollision cascade procedure has finished. NTAG21xF is now uniquely selected and
only this device will communicate with the NFC device even when other contactless
devices are present in the NFC device field. If more than one NTAG21xF is in the NFC
device field, a READ command from address 0 selects all NTAG21xF devices. In this
case, a collision occurs due to the different serial numbers. Any other data received when
the device is in this state is interpreted as an error. Depending on its previous state the
NTAG21xF returns to either the IDLE state or HALT state.
NTAG213F_216F
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 3.1 — 28 August 2013
262231
10 of 56
NXP [ NXP ]
