Data Sheet

MFRC522 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. 3.9 — 27 April 2016
112139 73 of 95
NXP Semiconductors
MFRC522
Standard performance MIFARE and NTAG frontend
This command automatically terminates when the MIFARE card is authenticated and the
Status2Reg register’s MFCrypto1On bit is set to logic 1.
This command does not terminate automatically if the card does not answer, so the timer
must be initialized to automatic mode. In this case, in addition to the IdleIRq bit, the
TimerIRq bit can be used as the termination criteria. During authentication processing, the
RxIRq bit and TxIRq bit are blocked. The Crypto1On bit is only valid after termination of
the MFAuthent command, either after processing the protocol or writing Idle to the
CommandReg register.
If an error occurs during authentication, the ErrorReg register’s ProtocolErr bit is set to
logic 1 and the Status2Reg register’s Crypto1On bit is set to logic 0.
10.3.1.10 SoftReset
This command performs a reset of the device. The configuration data of the internal buffer
remains unchanged. All registers are set to the reset values. This command automatically
terminates when finished.
Remark: The SerialSpeedReg register is reset and therefore the serial data rate is set to
9.6 kBd.