Data Sheet

Product data sheet Rev. 5.2 — 15 January 2007 5 of 17

NXP Semiconductors

MF1 IC S50

Functional specification

6.2.3 Select card

With the select card command the RWD selects one individual card for authentication and

memory related operations. The card returns the Answer To Select (ATS) code (= 08h),

which determines the type of the selected card. Please refer to the document

MIFARE‚ Standardized Card Type Identification Procedure for further details.

6.2.4 Three pass authentication

After selection of a card the RWD 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 memory operations are encrypted.

Fig 3. Three pass authentication

Request Standard Request All

Anticollision Loop

Get Serial Number

Select Card

3 Pass Authentication

sector specific

Read

Block

Write

Block

Decre-

ment

Incre-

ment

Re-

store

Halt

Transfer

Identification and Selection

Procedure

3 ms without collision

+ 1 ms for each collision

pical Transaction

Authentication Procedure

2 ms

Transaction

POR

Memory Operations

2.5 ms read block

6.0 ms write block

2.5 ms dec/increment

4.5 ms transfer