NXP Semiconductors
MF1S50YYX_V1
MIFARE Classic EV1 1K - Mainstream contactless smart card IC for fast and easy solution development
MF1S50yyX_V1 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2018. All rights reserved.
Product data sheet Rev. 3.2 — 23 May 2018
COMPANY PUBLIC 279232 5 / 36
• Control and Arithmetic Logic Unit: Values are stored in a special redundant format and
can be incremented and decremented
• EEPROM interface
• Crypto unit: The CRYPTO1 stream cipher of the MF1S50yyX/V1 is used for
authentication and encryption of data exchange.
• EEPROM: 1 kB is organized in 16 sectors of 4 blocks. One block contains 16 bytes.
The last block of each sector is called "trailer", which contains two secret keys and
programmable access conditions for each block in this sector.
8.2 Communication principle
The commands are initiated by the reader and controlled by the Digital Control Unit of
the MF1S50yyX/V1. The command response is depending on the state of the IC and for
memory operations also on the access conditions valid for the corresponding sector.
8.2.1 Request standard / all
After Power-On Reset (POR) the card answers to a request REQA or wakeup WUPA
command with the answer to request code (see Section 9.4, ATQA according to ISO/IEC
14443A).
8.2.2 Anticollision loop
In the anticollision loop the identifier of a card is read. If there are several cards in the
operating field of the reader, they can be distinguished by their identifier and one can
be selected (select card) for further transactions. The unselected cards return to the idle
state and wait for a new request command. If the 7-byte UID is used for anticollision and
selection, two cascade levels need to be processes as defined in ISO/IEC 14443-3.
Remark: For the 4-byte non-unique ID product versions, the identifier retrieved from the
card is not defined to be unique. For further information regarding handling of non-unique
identifiers see Ref. 6.
8.2.3 Select card
With the select card command the reader selects one individual card for authentication
and memory related operations. The card returns the Select AcKnowledge (SAK) code
which determines the type of the selected card, see Section 9.4. For further details refer
to the document Ref. 2.
8.2.4 Three pass authentication
After selection of a card the reader specifies the memory location of the following
memory access and uses the corresponding key for the three pass authentication
procedure. After a successful authentication all commands and responses are encrypted.
Remark: The HLTA command needs to be sent encrypted to the PICC after a successful
authentication in order to be accepted.