Transition signaling circuit and arbitrator using this circuit

An arbitrator, comprising:

• a plurality of devices which output a second control signal respectively to request use when a predetermined resource is shared;
• a plurality of transition signaling circuits disposed corresponding to said plurality of devices;
• and
• control means for executing arbitration among said devices, wherein
• said transition signaling circuit comprises:
• a first Muller C element with an inverter having a first positive input terminal for inputting a first transition signal, a first negative input terminal for inputting a feedback signal, and a first output terminal for outputting a second transition signal, where said second transition signal having a same logical level as said first transitional signal is output from said first output terminal when said first transition signal and said feedback signal are in different logical levels, and the previous state is maintained when said first transition signal and said feedback signal are in a same logical level;
• a first gate circuit having a first input terminal for inputting said second transition signal which is output from the first output terminal of said first Muller C element with an inverter, a second input terminal for inputting a first control signal, and a second output terminal which is operated by said first control signal and outputs an output signal corresponding to said second transition signal in ON status;
• a second Muller C element with an inverter having a second positive input terminal for inputting said output signal which is output from said first gate circuit, a second negative input terminal for inputting a third transition signal, and a third output terminal for outputting said feedback signal to the first negative input terminal of said first Muller C element with an inverter, where said feedback signal having a same logical level as said output signal is output from said third output terminal when said output signal of said first gate circuit and said third transition signal are in different logical levels, and the previous state is maintained when said output signal of said first gate circuit and said third transition signal are in a same logical level;
• a second gate circuit having a third input terminal connected to the third output terminal of said second Muller C element with an inverter, a fourth input terminal for inputting a second control signal whereby the logical level transits, and a fourth output terminal which is operated by said second control signal, turns ON when said second control signal is in the second logical level, and outputs a fourth transition signal corresponding to said feedback signal;
• and
• a third gate circuit, having a fifth input terminal connected to the third output terminal of said second Muller C element with an inverter, a sixth input terminal for inputting said second control signal, and a fifth output terminal which is operated by said second control signal, turns ON when said second control signal is in the first logical level, and outputs said first control signal corresponding to said feedback signal to the second input terminal of said first gate circuit, wherein
• an output terminal to output the fourth transition signal in the transition signaling circuit in a previous stage out of said plurality of transition signaling circuits is connected to an input terminal for inputting the first transition signal in the transition signaling circuit in the next stage, and the input terminal for inputting the third transition signal in the transition signaling circuit in the previous stage is connected to the output terminal for outputting the second transition signal in the transition signaling circuit in the next stage so that said plurality of transition signaling circuits are cascade-connected, and said control means outputs a first control signal to enable use to arbitrate the contention of devices when said second control signals which are output from said plurality of devices are input.