| 摘要 |
PROBLEM TO BE SOLVED: To give a bus usage right in compliance with a bus usage frequency of a bus mater for arbitration of the bus usage right with improved bus usage efficiency. SOLUTION: When there is a write/read request (Wreg or Rreq='1'), it is determined whether the number of accumulated data (Pw or Pr) in a write or read buffer is above a threshold value or not, or it is determined whether a request stored a moment before in a request queue is a write request or a read request (ID1=IDw or IDr) (S201, S202). When affirmative determination is given, the write/read request is accumulated in the request queues (S205, S206), and priority is changed according to a buffer availability, access made immediate before, and the number of serial access. COPYRIGHT: (C)2007,JPO&INPIT
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