A parameterized, CDC-safe asynchronous FIFO designed from scratch — lint-clean RTL, formal CDC sign-off, synthesis-validated at target frequency, all delivered in two weeks.
The client needed a fully parameterized asynchronous FIFO for a high-speed memory interface operating across two unrelated clock domains. Critically, it had to be production-ready: zero lint violations, formal CDC sign-off, synthesis validation at the target operating frequency, and complete documentation — all on a two-week schedule.
Async FIFOs are deceptively complex. Gray-code pointer synchronization, flag generation (full/empty/almost-full), and metastability protection all need to be structurally correct and formally provable — not just "simulated enough". Any structural CDC violation discovered late in the flow would cascade into synthesis and timing closure delays.
Rather than writing RTL and iterating on lint/CDC findings, we defined the micro-architecture and CDC crossings explicitly upfront — then validated the structural intent with formal tools before investing in a simulation testbench.
Micro-architecture documentation. Produced a one-page block diagram and signal-level CDC crossing specification before coding. Every synchronizer, every Gray-code converter, and every flag domain was explicitly documented and reviewed with the client.
Parameterized RTL in SystemVerilog. Implemented a fully parameterized design — depth, data width, almost-full/almost-empty thresholds, and synchronizer stages all compile-time configurable. All flip-flop inferences were synthesis-friendly with no latches.
Lint to zero. Every structural and guideline lint rule was resolved before CDC analysis began. No waivers were filed without root-cause justification and client approval.
Formal CDC closure. Ran formal CDC analysis and systematically resolved each crossing: two-flop synchronizers for single-bit signals, Gray-code arithmetic for multi-bit pointer buses. Formal sign-off was achieved with a clean report — no unresolved violations.
Simulation and synthesis validation. Written directed and pseudo-random simulation tests covering corner cases: simultaneous read/write, full/empty boundary conditions, and back-pressure scenarios. Synthesized at the target frequency with timing closure confirmed.
The deliverable package — RTL source, lint report, formal CDC closure report, synthesis results, simulation regression log, and micro-architecture document — was handed to the client at the end of week two, exactly on schedule.
The parameterized FIFO integrated into the client's subsystem without modification. No CDC violations surfaced in the downstream physical design flow. The client reused the same FIFO macro in a subsequent design revision with only parameter changes.
Lint-clean, CDC-safe, synthesis-validated — delivered with full documentation and no rework. Tell us about your block and we'll respond within 24 hours.
