Datasheet

Product data sheet

COMPANY PROPRIETARY

Rev. 3.0 — 17 October 2011

213830 9 of 30

NXP Semiconductors

NTAG203

NFC Forum Type 2 Tag compliant IC with 144 bytes user memory

8.2.5 Halt state

The halt and idle states constitute the second wait state implemented in the NTAG203. An

already processed NTAG203 can be set into the halt state using the HALT command. In

the anticollision phase, this state helps the NFC device to distinguish between processed

cards and cards yet to be selected. The NTAG203 can only exit this state on execution of

the WUPA command. Any other data received when the device is in this state is

interpreted as an error and the NTAG203 state is unchanged. Refer to the document

MIFARE collection of currently available application notes for correct implementation of an

anticollision procedure based on the idle and halt states and the REQA and WUPA

commands.

8.3 Data integrity

The following mechanisms are implemented in the contactless communication link

between NFC device and NTAG203 to ensure a reliable data transmission:

• 16 bits CRC per block

• Parity bit for each byte

• Bit count checking

• Bit coding to distinguish between "1", "0", and no information

• Channel monitoring (protocol sequence and bit stream analysis)

8.4 RF interface

The RF-interface is according to the standard for contactless smart cards

ISO/IEC 14443A (see Ref. 1 “

ISO/IEC”).

The RF-field from the NFC device is always present (with short modulation pulses when

transmitting), because it is used for the power supply of the card.

For both directions of data communication there is one start bit at the beginning of each

frame. Each byte is transmitted with a parity bit (odd parity) at the end. The LSBit of the

byte with the lowest address of the selected block is transmitted first. The maximum frame

length is 164 bits (16 data bytes + 2 CRC bytes = 16 * 9 + 2 * 9 + 1 start bit + 1 end bit).