Image Number 2 for United States Patent #5216635.
A system and method for requesting access to refresh a computer memory. Two lines are connected between a timer and arbiter. A memory refresh request signal is provided on the first line and is accorded a relatively low priority by the arbiter. If the first request is not granted within a predetermined period of time, a second memory refresh request signal is provided on the second line and is accorded a relatively high priority by the arbiter.