Hello @user_leo ,
MFRC522/3 is a highly integrated reader/writer IC for contactless communication at 13.56 MHz. The MFRC522 reader supports ISO/IEC 14443 A/MIFARE and NTAG. However, in addition MFRC523 reader also supports ISO/IEC 14443B mode. The registers and addresses of these two chips are almost the same, but the test registers are a little different, MFR523 has a few more of test register, you should pay attention to here, if need. But my suggest is when porting, it should be slightly modified for two different points. For more design details read the corresponding data sheet.
But not recommended for new designs. For new designs, please use recommended product CLRC663 plus. The replacement for these products is the CLRC663.
Best Regards,
Thanks,
kelly