I have been getting a lot of questions from our customers about traceability in the context of DO-254 and airborne FPGAs and ASICs. It seems that there are several new concepts and terminologies associated to traceability that are new to most of us. So I thought I would shed some light in this blog and explain the basic 5 terminologies. Also I have always liked the word “demystify”, but never had the chance to use it – so here is my chance.
Traceability – Traceability is the activity that maps all of the design and verification elements back to requirements to ensure that what is being built and tested is based on the requirements. Traceability is the correlation between system requirements, FPGA requirements, conceptual design, HDL design, post-layout design, verification test cases, testbench and test results.
Downstream Traceability – A top to bottom reporting activity that shows the mapping or correlation between system requirements, FPGA requirements, HDL design, test case, testbench and test results. Running a downstream traceability can expose FPGA requirements that are not implemented by any HDL function or not covered by a test case.
Upstream Traceability – A bottom to top reporting activity that shows the mapping or correlation between test results, testbench, test case, HDL design, FPGA requirements and system requirements. Running an upstream traceability can expose derived FPGA requirements or unused HDL functions. Tools like Spec-TRACER can also use upstream traceability to expose all of the design and verification elements associated to a FAILED simulation result.