NTAG213F/216F
NXP Semiconductors
NFC Forum T2T IC with 144/888 bytes user memory and field detection
8.2 RF interface
The RF-interface is based on the ISO/IEC 14443 Type A standard.
During operation, the NFC device generates an RF field. The RF field must always be
present (with short pauses for data communication) as it is used for both communication
and as power supply for the tag.
For both directions of data communication, there is one start bit at the beginning of each
frame. Each byte is transmitted with an odd parity bit at the end. The LSB of the byte with
the lowest address of the selected block is transmitted first. The maximum length of a
NFC device to tag frame is 163 bits (16 data bytes + 2 CRC bytes = 16×9 + 2×9 + 1 start
bit). The maximum length of a fixed size tag to NFC device frame is 307 bits (32 data
bytes + 2 CRC bytes = 32 9 + 2 9 + 1 start bit). The FAST_READ command has a
variable frame length depending on the start and end address parameters. The maximum
frame length supported by the NFC device needs to be taken into account when issuing
this command.
For a multi-byte parameter, the least significant byte is always transmitted first. As an
example, when reading from the memory using the READ command, byte 0 from the
addressed block is transmitted first, followed by bytes 1 to byte 3 out of this block. The
same sequence continues for the next block and all subsequent blocks.
8.3 Data integrity
Following mechanisms are implemented in the contactless communication link between
NFC device and the NTAG21xF to ensure reliable data transmission:
• 16 bits CRC per block
• parity bits for each byte
• bit count checking
• bit coding to distinguish between “1”, “0” and “no information”
• channel monitoring (protocol sequence and bit stream analysis)
NTAG213F_216F
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© NXP B.V. 2013. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 3.1 — 28 August 2013
262231
8 of 56
NXP [ NXP ]
