Clustered NOC, a suitable design for group communications in Network on Chip

In this paper, a Clustered NOC (C-NOC) is introduced to improve the performance of Hermes-NOC (H-NOC) in group communication. Each C-NOC switch has eight bi-directional ports connected to four neighbor switches and four local ports. With the same (IP) cores in both H-NOC and C-NOC networks, the ordinal size of C-NOC is 75% less than H-NOC. In corner-to-corner communication, C-NOC operates 29% faster than H-NOC. In random traffic mode, when the size of network is increased, then the average delay time of a packet in C-NOC is reached to this value in H-NOC. In group communication, a group of four IP cores is attached to a switch. The average delay time of a packet and number of clock pulses in C-NOC are 19.7% and 13.6% less than their values in H-NOC, respectively. This high performance of C-NOC is resulted from its internal switching. These comparisons in group communication show that C-NOC has superiority over H-NOC. 2011 Elsevier Ltd. All rights reserved.