Patent ID: 7073087

Claim:
A transition signal control unit, comprising a transition signal control circuit in which a loop for holding a token is created by a plurality of Muller C elements each with an inverter, and gate circuits, wherein said transition signal control circuit uses a device request signal DevReq to be input as a clock signal, and one of said plurality of Muller C elements with an inverter included in said transition signal control circuit transfers a token being held to a subsequent circuit according to input of the device request signal DevReq or a device response signal DevGrant, wherein said transition signal control circuit has input thereto a request signal ReqIn, a response signal AckIn, and a second control signal DevReq, and outputs a request signal ReqOut, a response signal AckOut, a first control signal DevGrant, and an output signal Q, and if said request signal ReqIn is input when said second control signal DevReq is not input and the token is not held, said transition signal control circuit receives said request signal ReqIn as a token and outputs said token as said request signal ReqOut, and if said second control signal DevReq is input, said transition signal control circuit does not output said request signal ReqOut but outputs said first control signal DevGrant, and holds said token.