ACS ACR33U-A1 SmartDuo Smart Card Reader - Manual (Page 51)

ACR33U-A1 – Reference Manual [email protected]
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8.3.7.3. WRITE_ONE_BYTE_MEMORY_CARD
To write one byte to the specified address of the inserted card. The byte is written to the card with
LSB first, i.e., the bit at card address 0 is regarded as the LSB of byte 0.
Four different WRITE modes are available for this card type, which are distinguished by a flag in the
command data field:
1. Write
The byte value specified in the command is written to the specified address. This command can
be used for writing personalization data and counter values to the card.
2. Write with carry
The byte value specified in the command is written to the specified address and the command is
sent to the card to erase the next lower counter stage. This write mode can therefore only be
used for updating the counter value in the card.
3. Write with backup enabled (SLE4436, SLE5536 and SLE6636 only)
The byte value specified in the command is written to the specified address. This command can
be used for writing personalization data and counter values to the card. Backup bit is enabled to
prevent data loss when card tearing occurs.
4. Write with carry and backup enabled (SLE4436, SLE5536 and SLE6636 only)
The byte value specified in the command is written to the specified address and the command is
sent to the card to erase the next lower counter stage. This write mode can therefore only be
used for updating the counter value in the card. Backup bit is enabled to prevent data loss when
card tearing occurs.
With all write modes, the byte at the specified card address is not erased prior to the write operation
and hence, memory bits can only be programmed from '1' to '0'.
The backup mode available in the SLE4436 and SLE5536 card can be enabled or disabled in the
write operation.
Command format (abData field in the PC_to_RDR_XfrBlock)
Pseudo-APDU
CLA INS P1 Byte Address MEM_L MODE BYTE
FFh D0h 00h 02h
Where:
Byte Address = Memory address location of the memory card
MODE:
Specifies the write mode and backup option
00h:
write
01h: write with carry
02h: write with backup enabled (SLE4436, SLE5536 and SLE6636 only)
03h: write with carry and with backup enabled (SLE4436, SLE5536 and
SLE6636 only)
BYTE: Byte value to be written to the card