Control Signal Multiplexing Based Asynchronous Data Transfer Scheme Using Multiple-Valued Bidirectional Current-Mode Circuits
Tomohiro Takahashi and Takahiro Hanyu
This paper presents a new asynchronous data transfer scheme based on control signal multiplexing and its circuit implementation. To multiplex control signals enables to overlap a request signal and an acknowledge signal. Therefore, simultaneous control of handshaking that the request signal and the acknowledge signal are sent at the same time is allowed, which leads that the cycle time of the asynchronous data transfer can be greatly reduced. Since the use of the proposed 2-color 1-phase dual-rail encoding method can detect the present signal state by observing the sum of their dual-rail codes, it is possible to control asynchronous operation correctly. The hardware for the proposed asynchronous data transfer is simply implemented by using multiple-valued current-mode logic circuits, because linear summation is realized by wiring without any active devices. It is demonstrated with a 0.18mm CMOS technology that the communication speed of the proposed hardware becomes about twice as fast as that of a corresponding CMOS circuit with a conventional protocol under the same power dissipation.