1. A method of accessing a memory with a microprocessor and having a cache memory wherein portions of memory contents of the memory can be intermediately stored, the method which comprises: upon receiving a request from the microprocessor for a stored data value, determining whether the requested stored data value is contained in the cache memory; if the data value is not contained in the cache memory, reading the data value from the memory; generating a control signal in random fashion and, if the data value is contained in the cache memory, reading the data value either from the cache memory or from the memory in dependence on the control signal.