Philips Semiconductors

Product Specification Rev. 3.1

February 2005

Functional Specification

Standard Label IC SL2 ICS20

10

3.2.5 WRITE ACCESS CONDITIONS

The Write Access Condition bits in block -1 determine the write access conditions for each of the 28 user

blocks and the special data block. These bits can be set only to 1 with a lock command (and never be

changed back to 0), i.e. already write protected blocks can never be written to from this moment on.

In block –2 each byte can be individually locked.

Block –1

Byte 0

Byte 1

Condition

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Write access

for block

number

3

2

1

0

-2

(3)

-2

(2)

-2

(1)

-2

(0)

11

10

9

8

7

6

5

4

Block -1

Byte 2

Byte 3

Condition

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Write access

for block

number

19

18

17

16

15

14

13

12

27

26

25

24

23

22

21

20

Changing of the Write Access conditions must be done in secure environment. The label must not be

moved out of the communication field of the antenna during writing! We recommend to put the label

close to the antenna and not to remove it during operation.