RASP: A General Logic Synthesis System for SRAM-Based FPGAs

In this paper, we present a general synthesis system for SRAM-based FPGAs named RASP. RASP consists of a core with a set of synthesis and optimization algorithms for technology independent logic synthesis and technology mapping for generating generic look-up tables (LUTs), together with a set of architecture-specific technology mapping routines to map the generic LUT network to programmable logic blocks (PLBs) for various SRAM-based FPGA architectures. Via a set of design representation converter routines, these architecture-independent and dependent synthesis algorithms are easily linked, and the entire system is seamlessly integrated into the design flow of commercial FPGA design systems. As a result, RASP can produce highly optimized designs for various SRAM-based FPGA architectures, and can be quickly adapted for new SRAM-based FPGA architectures. We compare RASP performance with that of several commercial synthesis systems on the MCNC logic synthesis benchmarks and a video compressor/decompressor. For almost all cases, RASP produces mapping solutions with significantly smaller critical path delay after place and route than current commercial synthesis systems.