Selective Extension of Routing Algorithms Based on Turn Model

Turn-model is a classical method for designing partially adaptive routing algorithms without virtual channels, and can also be the basis of fully adaptive routing algorithms. We propose a novel scheme, Selective Extension of Routing Algorithms based on turn model (SERA), which alleviates restrictions on turn and path selections if possible without adding any new buffers or virtual channels. SERA can improve adaptivity of the original routing algorithms, and maintain the deadlock-free property. Thus, SERA is an important extension of the previous turn model theory. To present the effectiveness of SERA in adaptive algorithms, we redesign two existing routing algorithms, Odd-Even and LEAR. Simulation results show that the SERA scheme achieves an average delay reduction of 6% compared to the original routing algorithms.