Two asynchronous data communication mechanisms (ACMs) using self-timed circuits are presented. Mutual exclusion elements are used to concentrate potential meta-stability to discrete points so that it can be resolved entirely within the ACMs themselves. Self-timed circuits allow the minimization of the interface between the reader and writer processes and the ACMs. Initial analysis shows that these VLSI solutions are more robust with regard to steering logic meta-stability, and can potentially run faster than solutions under fundamental mode assumptions. They are therefore more suitable for use in on-chip multi-processing systems.