Programmable fixed priority and round robin arbiter for providing high-speed arbitration and bus control method therein

A bus control method in which an arbiter operating in a fixed priority mode and in a round-robin mode controls a plurality of bus masters, the bus control method comprising:

• the arbiter rotating priority information related to bus masters stored in a register to give the highest priority to a bus master in response to pointer information which indicates the bus master currently having the highest priority in both the fixed priority mode and the round-robin mode, the pointer information defining the amount of rotation to be initiated so that reordered priority information is available in the register, and outputting the reordered priority information;
• at least one of the bus masters transmitting a request signal for occupation of a bus to the arbiter;
• the arbiter reordering requested priorities of the bus masters corresponding to the reordered priority information operation and outputting a request-reordering signal at a single, common request-reordering unit used for operation in both the fixed priority mode and the round-robin mode;
• the arbiter outputting a bus master-selecting signal according to priorities in response to the request-reordering signal;
• and
• the arbiter outputting a bus master grant signal to the bus masters in response to the bus master-selecting signal according to priorities, the bus master grant signal being output from a single, common grant-reordering unit used for operation in both the fixed priority mode and the round-robin mode.