Datasheet

MF1S50YYX All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 3.0 — 2 May 2011
196330 12 of 39
NXP Semiconductors
MF1S50yyX
MIFARE Classic 1K - Mainstream contactless smart card IC
8.7.1 Access conditions
The access conditions for every data block and sector trailer are defined by 3 bits, which
are stored non-inverted and inverted in the sector trailer of the specified sector.
The access bits control the rights of memory access using the secret keys A and B. The
access conditions may be altered, provided one knows the relevant key and the current
access condition allows this operation.
Remark: With each memory access the internal logic verifies the format of the access
conditions. If it detects a format violation the whole sector is irreversibly blocked.
Remark: In the following description the access bits are mentioned in the non-inverted
mode only.
The internal logic of the MF1S50yyX ensures that the commands are executed only after
a successful authentication.
Table 6. Access conditions
Access Bits Valid Commands Block Description
C1
3
, C2
3
, C3
3
read, write → 3 sector trailer
C1
2
, C2
2
, C3
2
read, write, increment, decrement,
transfer, restore
→ 2 data block
C1
1
, C2
1
, C3
1
read, write, increment, decrement,
transfer, restore
→ 1 data block
C1
0
,C2
0
, C3
0
read, write, increment, decrement,
transfer, restore
→ 0 data block
Fig 10. Access conditions
001aan00
3
151413121110987654321Byte Number
Description
0
Key A Key B (optional)Access Bits
user data
Byte 6 C2
3
C2
2
C2
1
C2
0
C1
3
C1
2
C1
1
C1
0
7Bit 6543210
Byte 7 C1
3
C1
2
C1
1
C1
0
C3
3
C3
2
C3
1
C3
0
Byte 8 C3
3
C3
2
C3
1
C3
0
C2
3
C2
2
C2
1
C2
0
Byte 9