System-level process variability compensation on memory organizations. On the scalability of multi-mode memories

Process variation and the dynamism of modern applications can degrade the expected performance of a system. Execution time can be severely affected by both factors, resulting in deadline violations and energy consumption overheads. Memory organizations, which account for a large part of the system energy and the time budgets, are especially vulnerable to process variation. Configurable - multimode - memories are a promising technology to deal with these problems, but they also introduce new issues that need to be solved. Essentially, adding configuration capabilities to the memories comes with a cost, both in memory area and control complexity; hence, we need to evaluate what is the minimum amount of re-configurability to satisfy system's constraints. In this paper, we analyze the scalability of configurable memories and highlight the relationship among mode allocation, memory mapping and data allocation.