MF3ICDX21_41_81_SDS

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Product short data sheet

COMPANY PUBLIC

Rev. 3.2 — 9 December 2015

145632

7 of 18

NXP Semiconductors

MF3ICDx21_41_81

MIFARE DESFire EV1 contactless multi-application IC

8.

Functional description

8.1 Contactless energy and data transfer

In the MIFARE system, the MIFARE DESFire EV1 is connected to a coil consisting of a

few turns embedded in a standard ISO/IEC smart card (see Ref. 8). A battery is not

needed. When the card is positioned in the proximity of the PCD antenna, the high-speed

RF communication interface allows data to be transmitted up to 848 kbit/s.

8.2 Anti-collision

An intelligent anti-collision mechanism allows more than one MIFARE DESFire EV1 in the

field to be handled simultaneously. The anti-collision algorithm selects each MIFARE

DESFire EV1 individually and ensures that the execution of a transaction with a selected

MIFARE DESFire EV1 is performed correctly without data corruption resulting from other

MIFARE DESFire EV1s in the field.

8.3 UID/serial number

The unique 7 byte (UID) is programmed into a locked part of the NV memory which is

reserved for the manufacturer. Due to security and system requirements these bytes are

write-protected after being programmed by the IC manufacturer at production time.

According to ISO/IEC 14443-3 (see Ref. 12) during the first anti-collision loop the cascade

tag returns a value of 88h and also the first 3 bytes of the UID, UID0 to UID2 and BCC.

The second anti-collision loop returns bytes UID3 to UID6 and BCC.

UID0 holds the manufacturer ID for NXP (04h) according to ISO/IEC 14443-3 and

ISO/IEC 7816-6 AMD 1.

MIFARE DESFire EV1 also allows Random ID to be used. In this case MIFARE DESFire

EV1 only uses a single anti-collision loop. The 3 byte random number is generated after

RF reset of the MIFARE DESFire EV1.

8.4 Memory organization

The 2/4/8 KB NV memory is organized using a flexible file system. This file system allows

a maximum of 28 different applications on one MIFARE DESFire EV1. Each application

provides up to 32 files. Every application is represented by its 3 bytes Application

IDentifier (AID).

Five different file types are supported; see Section 8.5.

A guideline to assign MIFARE DESFire AIDs can be found in the application note MIFARE

Application Directory (MAD); see Ref. 9.

Each file can be created either at MIFARE DESFire EV1 initialization (card

production/card printing), at MIFARE DESFire EV1 personalization (vending machine) or

in the field.

If a file or application becomes obsolete in operation, it can be permanently invalidated.

Commands which have impact on the file structure itself (e.g. creation or deletion of

applications, change of keys) activate an automatic rollback mechanism, which protects

the file structure from being corrupted.