Access to a memory is arbitrated by a memory arbiter. A plurality of first counters in the memory arbiter decrements service periods associated with isochronous memory requests, and a second counter decrements a service period associated with asynchronous memory requests, with the service periods for the first and second memory requests together comprising a schedule period. A scheduler logic circuit receives isochronous and asynchronous memory requests and generates a grant signal to service a received asynchronous request during the schedule period if time remains in the second counter. If there are any maintenance events signaled, the memory arbiter may correspondingly decrease the service period for the asynchronous request while the maintenance event is performed. |