Data Sheet

001052 © NXP B.V. 2007. All rights reserved.
Product data sheet Rev. 5.2 — 15 January 2007 11 of 17
NXP Semiconductors
MF1 IC S50
Functional specification
6.7.1 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 irreversible blocked.
Remark: In the following description the access bits are mentioned in the non-inverted
mode only.
The internal logic of the MF1 IC S50 ensures that the commands are executed only after
an authentication procedure or never.
Table 1. Memory Operations
Operation Description Valid for Block Type
Read reads one memory block read/write, value and sector
trailer
Write writes one memory block read/write, value and sector
trailer
Increment increments the contents of a
block and stores the result in
the internal data register
value
Decrement decrements the contents of a
block and stores the result in
the internal data register
value
Transfer writes the contents of the
internal data register to a block
value
Restore reads the contents of a block
into the internal data register
value
Table 2. 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