Programmable logic array integrated circuits with cascade connections between logic modules

Claim 1

A programmable logic array integrated circuit comprising: a plurality of substantially more than two programmable logic modules disposed on said circuit in a two-dimensional array, each of said logic modules having a plurality of input signal leads and at least one output signal lead for producing on said output signal lead an output signal which is substantially any logical function of the input signals on said input signal leads; a first plurality of conductors extending along a first dimension of said two-dimensional array; a second plurality of conductors extending along a second dimension of said two-dimensional array; a plurality of switches for making programmable connections between said output signal leads, said first and second conductors, and said input signal leads so that the output signal lead of substantially any of said logic modules can be connected to substantially any of said logic module input signals leads, each of said output signal leads being connectable to at least one of said conductors by said switches, each of said first conductors being connectable to a multiplicity of said second conductors by said switches, and each of said input signal leads being connectable to a multiplicity of said conductors by said switches; a plurality of auxiliary conductors, each of which is associated with a respective one of said logic modules so that a substantial majority of said logic modules have an associated auxiliary conductor, each of said auxiliary conductors connecting the output signal lead of the associated logic module to another receiving logic module which in a substantial majority of cases has an associated auxiliary conductor connecting its output signal lead to yet another receiving logic module, each of said auxiliary conductors making its connection between the associated logic module and the receiving logic module without making use of said first and second conductors or said input signal leads; and means associated with each receiving logic module and responsive to the signal received by said receiving logic module via an auxiliary conductor for selectively logically modifying the output signal on the output signal lead of said receiving logic module in accordance with the signal on said auxiliary conductor, wherein each receiving module produces an intermediate output signal which is substantially any logical function of said input signals of said receiving logic module, and wherein said means associated with said receiving logic module comprises: means for logically combining said intermediate output signal and the signal received by said receiving logic module via said auxiliary conductor to produce said output signal of said second logic module.