Evaluating energy consumption of homogeneous MPSoCs using spare tiles

The yield of homogeneous network-on-chip based multi-processor chips can be improved with the addition of spare tiles. However, the impact of this reliability approach on the chip energy consumption is not documented. For instance, in a homogeneous MPSoC, application tasks can be placed onto any tile of a defect-free chip. On the other hand, a chip with defective tile needs a special task placement, where the faulty tile is avoided. This paper presents a task placement tool and the evaluation of energy consumption of homogeneous NoC-based MPSoCs with spare tiles. Results show NoC energy consumption overhead ranging from 1 to 10% when considering up to three faults randomly distributed over the tiles of a 3×4 mesh network. The results also indicate that faults on the central tiles typically have more impact on energy overhead.