Programmable logic array integrated circuits

Abstract

A programmable logic array integrated circuit has a number of programmable logic modules which are grouped together in a plurality of logic array blocks (“LABs”). The LABs are arranged on the circuit in a two dimensional array. A conductor network is provided for interconnecting any logic module with any other logic module. In addition, adjacent or nearby logic modules are connectable to one another for such special purposes as providing a carry chain between logic modules and/or for connecting two or more modules together to provide more complex logic functions without having to make use of the general interconnection network. Another network of so-called fast or universal conductors is provided for distributing widely used logic signals such as clock and clear signals throughout the circuit. Multiplexers can be used in various ways to reduce the number of programmable interconnections required between signal conductors.

What is claimed is:  
     
         1 . A programmable logic array integrated circuit comprising: 
 a two dimensional array of Logic Array Blocks (“LABs”), each comprising: 
 a memory block having a plurality of memory columns;  
 control means coupled to said memory block; and  
 an intra-LAB plurality of conductors being programmably coupled to said control means;  
   a first plurality of conductors, each of which extends along a first dimension of said two dimensional array, said first conductors selectively and programmably coupled to said intra-LAB plurality of conductors; and    a second plurality of conductors, each of which extends along a second dimension of said two dimensional array, said second conductors programmably coupled to said memory block and said first plurality of conductors.