| 摘要 |
<P>PROBLEM TO BE SOLVED: To accept a low-priority request for a fixed period. <P>SOLUTION: Priority flag generation parts 42a and 42b count both first enable signals ENa1 and ENb1 and second enable signals ENa2 and ENb2. When each count value reaches a set count value, the priority flag generation part 42a, 42b inverts a priority flag SP1, SP2 to prioritize other levels of requests. Inter-level arbitration parts select either a high level validity signal or a low level validity signal according to the priority flags SP1 and SP2, and output the selected validity signal as an inter-level arbitration signal. A channel decision part assigns a bus use right to one of channel numbers SN1 to SN3 outputted from intra-level arbitration parts 41a to 41c whose levels accord to the inter-level arbitration signals SA1 and SA2. <P>COPYRIGHT: (C)2010,JPO&INPIT |
