T=0 protocol (smartcard) (T=0)
There are two standardized data exchange protocols for communication between a smart card and a smart card terminal (CTK): the byte-oriented, asynchronous half- duplex T=0 protocol and the block-oriented T=1 protocol. The smart card and the smart card terminal exchange their data with each other via the data exchange protocols.
The character-oriented T=0 protocol has a very simple structure and requires only a small amount of memory, about 300 bytes. With the T=0 protocol, the data provided by the smart card is queried by the smart card terminal with the command "Get Response". The protocol works with parity bits and is used in conjunction with the ATR protocol (Answer to Reset) in simple smart cards and the SIM card, among others, and has been standardized under the smart card specifications of ISO/ IEC 7816. There are specifications that are compatible with the T=0 specifications; these include the specifications of GSM 11.11 and those of Europay, Mastercard, Visa( EMV).