Formal Design and Verification of an Asynchronous SRAM Controller

We propose a new design of an asynchronous speed-independent SRAM controller that is tolerant to variations in supply voltage and can trade off performance for power consumption. It uses the standard 6T memory cells and is more robust than a comparable speed-independent design in literature due to a delay-insensitive interface to bit-lines. Designing an asynchronous SRAM controller presents a fascinating challenge for the application of formal models: As there is no global clocking, the switching events are inherently partially ordered, with concurrency, sequencing and choice being inextricably intertwined. In contrast to previous designs, the proposed controller was systematically developed, synthesised, and formally verified.

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