Patent ID: 7904626

Claim:
An access arbitration circuit performing an arbitration between a plurality of access requests when a plurality of access requests having different priorities are generated, the access arbitration circuit comprising: an issued access request retention unit which retains an issued access request selected as a result of a previous arbitration; a first interval determination circuit coupled to the issued access request retention unit, the first interval determination circuit being adapted to determine whether an interval is generated between an issued access processing generated by the issued access request retained by the issued access request retention unit and a first access processing generated by a first access request having the highest priority among the plurality of access requests; a second interval determination circuit, coupled to the issued access request retention unit, the second interval determination circuit being adapted to determine whether an interval is generated between the issued access processing and a second access processing generated by a second access request having a second-highest priority among the plurality access requests; and a third interval determination circuit which determines whether an interval is generated between the second access processing and the first access processing, wherein, in a case where the first interval determination circuit determines that an interval is generated between the issued access processing and the first access processing and the second interval determination circuit determines that no interval is generated between the issued access processing and the second access processing, a priority order of the first access request and the second access request are changed, wherein, in a case where the third interval determination circuit determines that an interval is generated between the second access processing and the first access processing, the priority order of the first access processing and the second access processing is not changed, and wherein a method of determining interval generation by the first interval determination circuit, the second interval determination circuit, and the third interval determination circuit extracts a bank address and a row address in an SDRAM access respectively from two access requests which are determination targets of the interval determination, and in a case where the two bank addresses are same and the two row addresses are not same, it is determined that an interval is generated between the two access requests.