MFRC522 datasheet(75/109 Pages) NXP

75 / 109 page

112132

Product data sheet

Rev. 3.2 — 22 May 2007

75 of 109

NXP Semiconductors

MFRC522

Contactless Reader IC

This command terminates automatically when the MIFARE® card is authenticated and the

bit MFCrypto1On in the Status2Reg register is set to logic 1.

This command does not terminate automatically when the card does not answer,

therefore the timer should be initialized to automatic mode. In this case, beside the bit

IdleIrq, the bit TimerIrq can be used as termination criteria. During authentication

processing the bit RxIrq and bit TxIrq are blocked. The Crypto1On bit is only valid after

termination of the authent command (either after processing the protocol or after writing

IDLE to the command register).

In case there is an error during authentication, the bit ProtocolErr in the ErrorReg register

is set to logic 1 and the bit Crypto1On in register Status2Reg is set to logic 0.

18.3.1.10

SoftReset Command

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 terminates

automatically when finished.

Remark: The SerialSpeedReg register is reset and therefore the serial data rate is set to

9.6 kbps.

MFRC522 Datasheet(PDF) 75 Page - NXP Semiconductors