An apparatus and method for scheduling requests to a source device is
provided. The apparatus comprises a high-priority request queue for
storing a plurality of high-priority requests to the source device; a
low-priority request queue for storing a low-priority request to the
source device, wherein a priority of one of the high-priority requests is
higher than the priority of the low-priority request; a history counter
for storing an information related to at least one requesting interval
between two adjacent high-priority requests; and a scheduling module for
scheduling the high-priority requests and the low-priority request
according to the information.