A method for controlling the processing of data in a data processor such that the data processor is connectable to a further device over a data link. The method comprising the steps of receiving data at an element of the data processor and if a set interval has elapsed following the receipt of the data, determining whether processing of the received data in accordance with a data transfer protocol has begun, and, if it has not, triggering such processing of the received data by a protocol processing element. The method then senses conditions pertaining to the data link and sets the interval in dependence on the sensed conditions.