Datasheet

Table Of Contents
PN532_C1 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2017. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 3.6 — 28 November 2017
115436 127 of 222
NXP Semiconductors
PN532/C1
Near Field Communication (NFC) controller
8.6.14.2 Polling sequence functionality for target
1. The 80C51 has to configure the CIU 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 CIU 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 CIU compares the system code, stored in byte 17 and 18 of the
Config Command with the system code received with the polling command by an
initiator. If the system code is equal, the CIU 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 PN532. If a valid
command, which is not a Polling command, is received by the CIU, no answer is sent
back and the command AutoColl is stopped. The received frame is stored in the FIFO.
8.6.14.3 Additional hardware support for FeliCa and NFC
Additionally to the polling sequence support for the FeliCa mode, the PN532 supports the
check of the LEN-byte.
The received LEN-byte is checked by the registers CIU_FelNFC1 and CIU_FelNFC2:
DataLenMin in register CIU_FelNFC1 defines the minimum length of the accepted frame
length. This register is 6 bits long. Each value represents a length of 4.
DataLenMax in register CIU_FelNFC2 defines the maximum length of the accepted
frame. This register is 6 bits long. Each value represents a length of 4. If set to logic 0 this
limit is switched off. If the length is not in the supposed area, the packed is not transferred
to the FIFO and receiving is kept active.
Example 1:
DataLenMin = 4
The length shall be greater or equal 16.
DataLenMax = 5
The length shall be smaller than 20. Valid area: 16, 17, 18, 19
Example 2:
DataLenMin = 9
The length shall be greater or equal 36.
DataLenMax = 0
The length shall be smaller than 256. Valid area: 36 to 255