ELECTRONIC LABELING SYSTEMS AND METHODS AND ELECTRONIC CARD SYSTEMS AND METHODS

A data transfer method in which a sending processor sends data to a receiving processor via a shared memory using a put pointer and a get pointer, the values of pointers indicate a next location in the shared memory to be written and to be read. The sending processor executes a data-sending process by (1) by referring to a counter of outstanding acknowledgements to determine if there is available space, (2) if there is available space, reading the get and put pointers and determining whether the put pointer is equal to one of plural partition indices which correspond to a number of partitions into which the shared memory is divided, (3) in the case where the value of the put pointer is equal to one of the plural predetermined partition indices, writing a command requesting the receiving processor to issue an acknowledgement and updating the counter of outstanding acknowledgements by adding one, (4) writing a block of data at a location of the put pointer, and (5) updating of the put pointer. The data-sending process is suspended when the counter of outstanding acknowledgements indicates that there is insufficient space in shared memory. An acknowledgement is received from the receiving processor and the counter of outstanding acknowledgements is updated by reducing it by one. The data-sending process is re-executed after the receiving processor issues the acknowledgement.