AN108711 - NXP Semiconductors

Philips Semiconductors
When acting as NFC initiator the flow could look as follows:
Application Note
Tips and Tricks for PN51x Integration
• In the first step the host controller decides which mode (active or passive) will be
used.
o If active mode is chosen, the left branch has to be followed. The host
controller can freely select the desired bit rate and can start with an
ATR_REQ command.
If a collision occurs (detected by an invalid CRC), resend an
ATR_REQ and evaluate the ATR_RES as long as the CRC is
not valid.
o If passive mode is chosen, the initiator’s host has to decide which bit rate
will be used.
If 106kBit/s is used, the rightmost branch has to be followed. The
branch until SAK is fully compliant to the ISO/IEC 14443-3A
specification. After selection of a target the SEL_RES byte has
to be checked.
• If bit 6 of SEL_RES is set to 1, the counterpart is a
device capable of handling the NFCIP-1 protocol.
• If bit 5 of SEL_RES is set to 1, the device can handle the
ISO/IEC 14443-4 protocol.
• If none of these is set the counterpart is a proprietary
device. This is then likely to be a Mifare card.
If either 212kBit/s or 424kBit/s is selected, the protocol starts
with the FeliCa compatible POLLING_REQUEST. The response,
namely POLLING_RESPONSE can be used to determine if the
counterpart is capable of handling the NFCIP-1 protocol.
If the first two bytes of the NFCID2 is equal to 01h FEh the
device supports NFCIP-1.
Otherwise it does not support NFCIP-1 and is likely to be a
FeliCa card.
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Application note Rev. 01.10 — 11. May 2006 12 of 37