| 摘要 |
PURPOSE:To easily perform the preference processing in response to the request degrees by giving the collective and integrated judgement/processing to the weight that set individually plural request input signals as well as the request frequencies produced within a fixed time. CONSTITUTION:A timer circuit 1 produces a fixed time (t) and the input frequencies of a request signal A or B produced within the time (t) are counted by the weighting frequency counting circuits 2 and 3. Then the count values A and B are compared with each other by a comparator 4 for decision of the priority. In this case, the count value of the signal B having a low weighting level can have a higher weighting level than the signal A having a high weighting level as long as the request frequency of the signal B is higher than the signal A. At this instant, the priority is changed to the signal B and therefore the selection signal which gives the priority to the signal B is applied to a request answer output selection circuit 5. Then the signal B is sent to a data bus as a request answer B and processed with priority. |
