NXP Semiconductors
MF1S70YYX_V1
MIFARE Classic EV1 4K - Mainstream contactless smart card IC for fast and easy solution development
MF1S70yyX_V1 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2017. All rights reserved.
Product data sheet Rev. 3.2 — 23 November 2017
COMPANY PUBLIC 279332 10 / 37
An example of a valid value block format for the decimal value 1234567d and the block
address 17d is shown in Table 4. First, the decimal value has to be converted to the
hexadecimal representation of 0012D687h. The LSByte of the hexadecimal value is
stored in Byte 0, the MSByte in Byte 3. The bit inverted hexadecimal representation of
the value is FFED2978h where the LSByte is stored in Byte 4 and the MSByte in Byte 7.
The hexadecimal value of the address in the example is 11h, the bit inverted
hexadecimal value is EEh.
Table 4. Value block format example
Byte Number 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Description value value value adr adr adr adr
Values [hex] 87 D6 12 00 78 29 ED FF 87 D6 12 00 11 EE 11 EE
8.6.3 Sector trailer
The sector trailer is always the last block in one sector. For the first 32 sectors this is
block 3 and for the remaining 8 sectors it is block 15. Each sector has a sector trailer
containing the
• secret keys A (mandatory) and B (optional), which return logical "0"s when read and
• the access conditions for the blocks of that sector, which are stored in bytes 6...9. The
access bits also specify the type (data or value) of the data blocks.
If key B is not needed, the last 6 bytes of the sector trailer can be used as data bytes.
The access bits for the sector trailer have to be configured accordingly, see Section
8.7.2.
Byte 9 of the sector trailer is available for user data. For this byte the same access rights
as for byte 6, 7 and 8 apply.
When the sector trailer is read, the key bytes are blanked out by returning logical zeros.
If key B is configured to be readable, the data stored in bytes 10 to 15 is returned, see
Section 8.7.2.
All keys are set to FFFF FFFF FFFFh at chip delivery and the bytes 6, 7 and 8 are set to
FF0780h.
001aan013
151413121110987654321Byte Number 0
Key A Key B (optional)Access BitsDescription
Figure 9. Sector trailer
8.7 Memory access
Before any memory operation can be done, the card has to be selected and
authenticated as described in Section 8.2. The possible memory operations for an
addressed block depend on the key used during authentication and the access
conditions stored in the associated sector trailer.
Table 5. Memory operations
Operation Description Valid for Block Type
Read reads one memory block read/write, value and sector trailer