Datasheet

Product data sheet

COMPANY PUBLIC

Rev. 5.2 — 16 June 2016

111352 92 of 137

NXP Semiconductors

PN512

Full NFC Forum-compliant frontend

11.7 Hardware support for FeliCa and NFC polling

11.7.1 Polling sequence functionality for initiator

1. Timer: The PN512 has a timer, which can be programmed in a way that it generates

an interrupt at the end of each timeslot, or if required an interrupt is generated at the

end of the last timeslot.

2. The receiver can be configured in a way to receive continuously. In this mode it can

receive any number of packets. The receiver is ready to receive the next packet

directly after the last packet has been received. This mode is active by setting the bit

RxMultiple in register RxModeReg to 1 and has to be stopped by software.

3. The internal UART adds one byte to the end of every received packet, before it is

transferred into the FIFO-buffer. This byte indicates if the received byte packet is

correct (see register ErrReg). The first byte of each packet contains the length byte of

the packet.

4. The length of one packet is 18 or 20 bytes (+ 1 byte Error-Info). The FIFO has a

length of 64 bytes. This means three packets can be stored in the FIFO at the same

time. If more than three packets are expected, the host controller has to empty the

FIFO, before the FIFO is filled completely. In case of a FIFO-overflow data is lost (See

bit BufferOvfl in register ErrorReg).

11.7.2 Polling sequence functionality for target

1. The host controller has to configure the PN512 with the correct polling response

parameters for the polling command.

2. To activate the automatic polling in Target mode, the AutoColl Command has to be

activated.

3. The PN512 receives the polling command send out by an initiator and answers with

the polling response. The timeslot is selected automatically (The timeslot itself is

randomly generated, but in the range 0 to TSN, which is defined by the Polling

command). The PN512 compares the system code, stored in byte 17 and 18 of the

Config Command with the system code received by the polling command of an

initiator. If the system code is equal, the PN512 answers according to the configured

polling response. The system code FF (hex) acts as a wildcard for the system code

bytes, i.e. a target of a system code 1234 (hex) answers to the polling command with

one of the following system codes 1234 (hex), 12FF (hex), FF34 (hex) or FFFF (hex).

If the system code does not match no answer is sent back by the PN512.

If a valid command is received by the PN512, which is not a Polling command, no

answer is sent back and the command AutoColl is stopped. The received packet is

stored in the FIFO.