ACS ACK30 Smart Keyboard - Manual (Page 25)

ACR30 Reference Manual
Version 3.3 January 2009 Page 25 of 44
ACR30
b) 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.
With either write mode, 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 card can be enabled or disabled in the write operation.
Command format
Instruction
Code
Data length Data
ADDR MODE BYTE
91
H
04
H
00
H
ADDR Byte address of byte to be written
MODE Specifies the write mode and backup option (SLE4436)
00
H
: write
01
H
: write with carry
02
H
: write with backup enabled
03
H
: write with carry and with backup enabled
BYTE Byte value to be written to the card
Response data format
No response data
9.2.1.5. PRESENT_TRANSPORT_CODE (*)
To submit the transport code to the card in order to enable the card personalization mode. The
following actions are executed by the ACR30:
- search a '1' bit in the presentation counter and write the bit to '0'
- present the specified code to the card
The ACR30 does not try to erase the presentation counter after the code submission! The application
software through a separate ‘Write with carry’ command must do this.