Why shared memory matters to VLSI design: The BSR is as powerful as reconfiguration

We investigate the relative computational power of parallel models with directed reconfigurable buses and the most powerful shared memory model, the broadcast with selective reduction (BSR). We show that these two models have the same computational power in a strong sense. We also show that the Collision write conflict resolution rule is universal on models with directed reconfigurable buses (meaning that complex conflict resolution rules such as priority or even combining can be simulated by collision with constant-time overhead). Consequences of these finding, including some real time consideration, are discussed.