Patent ID: 7127529

Claim:
A method of operating a smart card and smart card terminal to simulate asynchronous communication between the smart card and smart card terminal such that either the smart card or the smart card terminal may operate as master and the other operating as slave wherein the smart card and smart card terminal communicate in a half-duplex protocol, comprising: sending a first message from the smart card terminal to the smart card, wherein if the smart card terminal has no data to send the smart card, the first message is a polling packet; receiving the first message at the smart card; upon receipt of the first message, if the smart card has data to send, sending a second message from the smart card to the terminal containing a length of data indication; upon receipt of the second message from the smart card, sending a third message from the terminal to the smart card as an indication from the terminal to the smart card to commence sending the data; and sending a message containing the data from the smart card to the terminal.