Towards automated ECOs in FPGAs

ABSTRACT

During the FPGA design flow, engineering change orders (ECOs) have become an essential methodology to apply late-stage specification changes and bug fixes. ECOs are beneficial since they are applied directly to a place-and-routed netlist which preserves most of the engineering effort invested previously. Unfortunately, designers often apply ECOs in a manual fashion which has an unpredictable impact on the design's final correctness and end costs. As a solution, we introduce an automated method to tackle the ECO problem. Specifically, we introduce a resynthesis technique which can automatically update the functionality of a circuit by leveraging the existing logic within the design; thereby removing the inefficient manual effort required by a designer. Our technique is robust enough to handle a wide range of changes. Furthermore, our technique can successfully make late-stage functional changes while minimally perturbing the place-and-routed netlist: something that is necessary for ECOs. When applied to several benchmarks on Altera's Stratix architecture, we show that our approach can automatically apply ECOs in over 80% of the cases presented. Furthermore, our technique does this with a minimal impact to the circuit performance where on average over 90% of the placement and routing wires remain unchanged.

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INDEX TERMS

Primary Classification:
  B. Hardware
  B.6 LOGIC DESIGN
      B.6.3 Design Aids
          Subjects: Automatic synthesis

General Terms:
Algorithms, Design, Verification

Keywords:
boolean satisfiability, fpga, optimization, pst, resynthesis