Data reception apparatus for receiving and processing a data stream including a stream of data units, the data apparatus comprising: a buffer; a data reception controller for receiving data units from the data stream, storing received data units in the buffer, and if the amount of data from the data stream that is stored in the buffer exceeds a predetermined amount, generating a buffer load interrupt for the data stream; and a processor responsive to the buffer load interrupt to: a) disable handling of further buffer load interrupts for the data stream; and b) repeatedly activate a routine to process a single data unit from the data stream that is stored in the buffer until all the data units in the buffer have been processed and then reset the buffer.