Radar Sample Width Signedness Audit

Purpose

Check fixed-width sample arithmetic for signedness, truncation, overflow, and sign-extension errors. This workflow turns the concern into a traceable engineering contract for the AERIS-10 project, while keeping simulations, software behavior, and physical measurements clearly distinguished.

Required inputs

Inspect FPGA DSP modules, ADC interfaces, and fixed-point types. Gather the authoritative interface/schema, the selected board or bitstream revision, existing tests, and the expected result. Prefer synthetic input vectors, simulator outputs, host mocks, and de-energized design inspection.

Workflow

1. Trace FPGA DSP modules, ADC interfaces, and fixed-point types and record source paths, board/design revision, input/output ownership, and the existing validation entry points.
2. Define pass/fail invariants for check fixed-width sample arithmetic for signedness, truncation, overflow, and sign-extension errors.; explicitly document units, widths, timing assumptions, safe defaults, and unsupported states where relevant.
3. Exercise Positive/negative full-scale samples, width changes, saturation, wraparound, and cast boundaries with deterministic simulation or mocked hardware. Include normal, boundary, malformed, reset/cancellation, and failure cases without relying on uncontrolled physical targets.
4. Produce A width/signedness map with directed test vectors. Run the narrow test and relevant regression suite, capture actual outputs, and separate verified findings from assumptions requiring qualified hardware review.

Validation checklist

• The requirement is represented as an explicit, repeatable assertion or review criterion.
• Boundary values and at least one injected failure are included.
• Units, revision, data origin, and interface timing are stated where they change interpretation.
• Test results cite the exact command/tool run and repository revision.
• Simulation/mock evidence is not misrepresented as hardware measurement or certification.
• RF, power, motion, or external-interface tests stop when the approved safety envelope is unknown or violated.

Required output

Deliver A width/signedness map with directed test vectors. Attach the paths reviewed, fixture or simulation identifiers, test commands and observed results, unresolved safety/compliance questions, and a clear distinction between code-level evidence and physical verification still required.

Boundaries and failure handling

Use synthetic inputs, host tests, simulation, or de-energized inspection wherever possible. Physical RF or powered hardware work requires qualified supervision, an approved lab procedure, regional compliance review, and functioning safety/thermal interlocks. Do not bypass an interlock, increase transmitter power or range as an objective, or turn signal-processing workflows into instructions for targeting people. If the design revision, emissions permission, termination, cooling, or measurement setup is uncertain, stop and document the blocker.

Trigger examples

• Positive: A maintainer needs to check fixed-width sample arithmetic for signedness, truncation, overflow, and sign-extension errors..
• Negative: Ignoring overflow because the nominal test signal remains inside the expected range.