Datasheet

Product data sheet

COMPANY PUBLIC

Rev. 3.0 — 2 May 2011

196330 18 of 39

NXP Semiconductors

MF1S50yyX

MIFARE Classic 1K - Mainstream contactless smart card IC

10. UID Options and Handling

The MF1S50yyX product family offers two delivery options for the UID which is stored in

block 0 of sector 0.

• 7-byte UID

• 4-byte NUID (Non-Unique ID)

This section describes the MIFARE Classic MF1S50yyX operation when using one of the

2 UID options with respect to card selection, authentication and personalization. See also

Ref. 6

for details on how to handle UIDs and NUIDs with MIFARE Classic products.

10.1 7-byte UID Operation

All MF1S500yXDyy products are featuring a 7-byte UID. This 7-byte UID is stored in

block 0 of sector 0 as shown in Figure 7

. The behaviour during anti-collision, selection and

authentication can be configured during personalization for this UID variant.

10.1.1 Personalization Options

The 7-byte UID variants of the MF1S50yyX can be operated with four different

functionalities, denoted as UIDFn (UID Functionality n).

1. UIDF0: anti-collision and selection with the double size UID according to ISO/IEC

14443-3

2. UIDF1: anti-collision and selection with the double size UID according to ISO/IEC

14443-3 and optional usage of a selection process shortcut

3. UIDF2: anti-collision and selection with a single size random ID according to ISO/IEC

14443-3

4. UIDF3: anti-collision and selection with a single size NUID according to ISO/IEC

14443-3 where the NUID is calculated out of the 7-byte UID

The anti-collision and selection procedure and the implications on the authentication

process are detailed in Section 10.1.2

and Section 10.1.3.

The default configuration at delivery is option 1 which enables the ISO/IEC 14443-3

compliant anti-collision and selection. This configuration can be changed using the

‘Personalize UID Usage’ command. The execution of this command requires an

authentication to sector 0. Once this command has been issued and accepted by the

PICC, the configuration is automatically locked. A subsequently issued ‘Personalize UID

Usage’ command is not executed and a NAK is replied by the PICC.

Remark: As the configuration is changeable at delivery, it is strongly recommended to

send this command at personalization of the card to prevent unwanted changes in the

field. This should also be done if the default configuration is used.

Remark: The configuration only becomes effective only after PICC unselect or PICC field

reset.