When a unit connected to a data transfer bus on which data transfer is controlled synchronously with a bus cycle makes a request for using the bus, permission is granted to one of the units which have made the request. The permission to use the bus is switched over at a bus cycle when data transfer is...http://www.google.com/patents/US5402421?utm_source=gb-gplus-sharePatent US5402421 - Bus control device and bus control method
