Semiconductor integrated circuit capable of realizing logic functions

Abstract

A semiconductor integrated circuit is constructed with composite pass-transistor logic circuits serving as elementary circuit units each including a plurality of pass-transistor logic trees and a multiple-input logic gate. A wide variety of logical operations, even complex opearations, can be efficiently expressed using the composite pass-transistor logic circuit, and the resultant logic circuit can operate at a high speed. Thus, the semiconductor integrated circuit of the present invention can realize various logic functions required for various users in an efficient fashion. The present invention is particularly useful when applied to a field-programmable gate array integrated circuit, since complex logical operations can be expressed in a simple and efficient fashion by the composite pass-transistor logic circuits. The gate array integrated circuit obtained in accordance with the present invention can operate at a high speed with low power consumption. The present invention also discloses a basic cell suitable for use in an integrated circuit in the form of a gate array, and more particularly, a programmable logic block for use in a field programmable gate array integrated circuit.