Parallel overloaded CDMA crossbar for network on chip

Abstract

For high performance of Network on Chip (NoC), Code Division Multiple Access (CDMA) technique is used recently due to its fixed communication delay, reduced area utilisation and low power consumption. The CDMA system uses Walsh based spreading code which improves the bandwidth efficiency. On the contrary, it is not effective when the number of nodes present in the system increases. Overloaded CDMA (OCDMA) is presented for such large network systems. In this paper, OCDMA crossbar is modified and advanced with parallel encoding and decoding operation using orthogonal gold codes for improving the speed of crossbar thereby obtaining high performance in NoC switch. A modified crossbar consisting of extra processing elements is used to enhance the performance of NoC based System on Chip (SoC) system. This work is simulated on Xilinx tool and implemented in Vertex-6 (XC6VLX760) Field Programmable Gate Array (FPGA) device. The proposed work is implemented for four ports, eight ports and sixteen ports with deterministic X-Y routing algorithm in 3 3 NoC design with mesh topology. This NoC switch shows 9.79% improvement in delay and shows 20.76% improvement in power consumption when compared to the existing CDMA NoCs for 8 bit data packet.