Manchester type carry propagation circuit

摘要

A Manchester type carry propagation circuit of this invention has a precharge clock signal (24) applied to the gate of an NMOS transistor (23) having a high threshold, to precharge a carry signal line (22) to an intermediate potential. When a carry signal (27) of the preceding stage attains to the "H" level, a transistor (26) turns on to transmit the potential of the carry signal line (22) to the succeeding stage, and when a carry propagation signal (37) attains to the "H" level, a transistor (36) turns on to propagate a carry of the preceding stage to the carry signal line (22). Then, the intermediate level of the carry signal line (22) is pulled up to the level of the source potential (21) by a pull-up circuit (30). Consequently, the level of the carry signal line (22) can be propagated to the succeeding stage at high speed.