Datasheet
PN512 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2016. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 5.2 — 16 June 2016
111352 37 of 137
NXP Semiconductors
PN512
Full NFC Forum-compliant frontend
8.2.2.2 ModeReg
Defines general mode settings for transmitting and receiving.
Table 49. ModeReg register (address 11h); reset value: 3Bh, 00111011b
7 6 5 4 3 2 1 0
MSBFirst Detect Sync TxWaitRF RxWaitRF PolSigin ModeDetOff CRCPreset
Access
Rights
r/w r/w r/w r/w r/w r/w r/w r/w
Table 50. Description of ModeReg bits
Bit Symbol Description
7 MSBFirst Set to logic 1, the CRC co-processor calculates the CRC with MSB
first and the CRCResultMSB and the CRCResultLSB in the
CRCResultReg register are bit reversed.
Note: During RF communication this bit is ignored.
6 Detect Sync If set to logic 1, the contactless UART waits for the value F0h before
the receiver is activated and F0h is added as a Sync-byte for
transmission.
This bit is only valid for 106 kbit during NFCIP-1 data exchange
protocol.
In all other modes it shall be set to logic 0.
5 TxWaitRF Set to logic 1 the transmitter in reader/writer or initiator mode for
NFCIP-1 can only be started, if an RF field is generated.
4 RxWaitRF Set to logic 1, the counter for RxWait starts only if an external RF field
is detected in Target mode for NFCIP-1 or in Card Communication
mode.
3 PolSigin PolSigin defines the polarity of the SIGIN pin. Set to logic 1, the
polarity of SIGIN pin is active high. Set to logic 0 the polarity of SIGIN
pin is active low.
Note: The internal envelope signal is coded active low.
Note: Changing this bit will generate a SiginActIRq event.
2 ModeDetOff Set to logic 1, the internal mode detector is switched off.
Note: The mode detector is only active during the AutoColl command.
1 to 0 CRCPreset Defines the preset value for the CRC co-processor for the command
CalCRC.
Note: During any communication, the preset values is selected
automatically according to the definition in the bits RxMode and
TxMode.
Value Description
00 0000
01 6363
10 A671
11 FFFF