Synthesis of FPGAs and Testable ASICs

Abstract

Industrial designers and educators who plan to design microelectronic systems (e.g. hardware accelerators, co-processors, etc.) are increasingly capturing their designs using hardware description languages such as VHDL and Verilog. The designs are then most often synthesized into programmable logic components such as field-programmable gate arrays (FPGAs) offered by Xilinx, Altera, Actel and others. This approach places the emphasis on high-level design which reduces time to market by relying on synthesis software and programmable logic to produce working prototypes rapidly. These prototypes may then be altered as requirements change or converted into high-volume mask gate arrays or other application-specific integrated circuits (ASICs) when the demand is known to be sufficient. These ASICs, however, must be designed to be testable to screen out those with manufacturing defects. Hence, scan logic must be inserted, test vectors generated and fault grading performed to ensure a high level of testability. These efforts complicate and delay the conversion of FPGA designs to ASICs but must be considered by designers of microelectronic systems. Topics covered include: design flow; system partitioning; hardware description languages (HDLs); specifying behavioral control; specifying structural components; critical paths; placement and routing; technology choices; FPGA applications; rapid prototyping; retargeting; manufacturing defects; scan chain insertion; test vector generation; fault grading, and ASIC production