Storage structure and control attributes of the smart M1 card

Storage structure and control attributes of the smart M1 card

Smart M1 Card Storage Structure:
The M1 card is divided into 16 sectors, each containing 4 blocks (blocks 0~3), totaling 64 cells, addressed by block number 0~63. Block 0 in sector 0 (i.e., absolute address block 0) is used to store vendor code, which is solidified and cannot be changed. Blocks 0, 1, and 2 in the other sectors are data blocks used to store data; Block 3 is the control block, storing password A, access control, and password B. Its structure is as follows:
A0A1A2A3A4A5 FF 07 80 69 B0B1B2B3B4B5
Password A (6 bytes) Access control (4 bytes) Password B (6 bytes)

Control attributes
Each sector's password and access control are independent, allowing you to set your own password and access control according to actual needs. In Access Control, each block has three corresponding control bits, defined as follows:
Block 0: C10 C20 C30
Block 1: C11 C21 C31
Block 2: C12, C22, C32
Block 3: C13 C23 C33
The three control bits exist in the access control byte in both forward and reverse forms, determining the access permissions of the block (for example, decreasing operations must verify KEY A, adding operations must verify KEY B, etc.). The positions of the three control bits in access control bytes are as follows (byte 9 is a backup byte, default value is 0x69)