HopliteRT*: Real-Time NoC for FPGA

This article was presented in part at the International Conference on Embedded Software 2020 and appears as part of the ESWEEK-TCAD special issue.With the increasing number of computation nodes integrated in multi and many-core platforms, network-on-chips (NoCs) emerged as a new communication medium in systems-on-chips (SoCs). HopliteRT is a new NoC design that was recently proposed to address the needs of real-time systems whilst respecting the constraints of field-programmable gate array (FPGA) platforms. In this article, we: 1) introduce priority-based routing in HopliteRT; 2) change the network topology in order to improve the packets’ worst-case traversal time (WCTT); 3) identify a flaw in the existing timing analysis of HopliteRT; and 4) develop a new timing analysis that is proven correct. We also show by means of experiments that the modifications of HopliteRT proposed in this article allows for at least 2× improvement on the worst and average case traversal time of high priority packets, without impacting the quality of service of low-priority packets. The timing properties of high priority flows are greatly improved for negligible additional hardware costs. The proposed NoC has been implemented in Verilog and synthesized for a Xilinx Virtex-7 FPGA platform.