N-way ring and square arbiters

In this paper, we propose two new N-way arbiter circuits. One circuit is based on the token-ring arbiters and another circuit is based on the mesh arbiters. The idea of the ring arbiter is to generate a lock signal by a token which is based on the non-return-to-zero signaling. It can achieve low latency and high throughput arbitration for a heavy work load environment. The idea of the mesh arbiter is to perform arbitrations between N/2 pairs at the same level and repeat them N-1 times. They can issue grant signals fairly. In this paper, we compare the performance of these N-way arbiters using 65nm process technologies qualitatively and quantitatively. We conclude that the proposed mesh arbiters are suitable when the number of inputs is 5 or less. We also conclude that we must select the appropriate arbiters considering tradeoff between latency, throughput, area, and energy when the number of inputs is larger than 5.