Microcontroller › 8051 › RC522 with 8051 › Hi AlainRC522 support three
February 7, 2017 at 8:53 am #14412
RC522 support three modes of serial communication: SPI, USART, I2C. You can use any one of them, as 8051s can handle all these three.
Check out this datasheet: http://www.nxp.com/documents/data_sheet/MFRC522.pdf
You will find the related content on page number 9-23.