Field programmable gate arrays using semi-hard multicell macros

Abstract

A computer implemented method for the automated placement and routing in the design of field programmable gate arrays achieves optimal timing. In a library of primitives and macros from which a designer may choose to implement a given circuit design, at least some of said macros are 'semi-hard' macros where direct connections and relative placements are specified while local bus routing is requested in a manner that does not restrict macro placement. A logical netlist containing references to macros and how to connect them together to perform a logical function is first created. The logical netlist is then translated to a physical netlist using a mapper function. This physical netlist for the semi-hard macros specifies what is to be connected but not how. The best place to put each macro on the field programmable gate array is found using a placer function. The placer function thus determines an absolute position of the macros. Pre-defined macro direct connections are routed using a router function. The router function determines an optimal path to connect the semi-hard macros. Finally, a bitstream is generated from placement and routing information developed by the placer and router functions to program the field programmable gate array to perform the netlist logical function.