A Standard-basis Based CDMA NOC Design

International Journal of Research and Scientific Innovation (IJRSI) | Volume V, Issue IX, September 2018 | ISSN 2321–2705

A Standard-basis Based CDMA NOC Design

Prasad Nathu M, Dr. Praveen J

 Alvas Institute of Technology, Mangaluru, Karnataka, India

Abstract— NOC’s has come into existence to resolve the problems in the conventional bus based on-chip communication. Earlier circuit switched and packet switched methods were employed in NOC’s and recently CDMA based NOC’s have gained popularity because of its capability of handling communication nodes concurrently. The CDMA technique is very handy in SOCs for establishing communication among a large number of integrated components on the same chip. The CDMA spreading codes for NOC such as Walsh codes were used for implementing the encoding/decoding part of CDMA and recently a new spreading code called Standard-basis Based (SB) was used in the encoding/Decoding process. In this paper, the CDMA NOC using the Walsh codes and SB codes are implemented individually on FPGA SPARTAN III kit. The design is coded in Verilog on Xilinx ISE and simulated using Modelsim 6.3f. The CDMA NOC SB and WB Coding designs are implemented on FPGA –Atrix7 and the performances are compared. The implementation results of the two methods are compared. The designed SB code CDMA NOC has improved 30.11% area in LUT slices, 12% reduction in total power consumption and 4% faster.

Keywords—Network on Chip; CDMA; Spreading code; FPGA;

I. INTRODUCTION

In SOC’s the increase in the number of IP cores have made the traditional bus based on chip communication replaced by Network -on-chip to reduce the complexity and provide parallelism in communication between IP cores implemented in SOCs. NOC’s provide a structure for providing communication between a large number of IP cores and other components on Chip. The NOC structures are of two types circuit-switched and packet-switch networks. In circuit- switch type, routing resources are allocated by the NOC to establish a link between the sender and the receiver.TDM and FDM are the two techniques used by the circuit switched NOC to share the bandwidth. The circuit switched NOC type suffer from complexity and contention problem for a large number of interconnected components such as found in SOC’s. Packet switch NOC overcomes the shortfalls of circuit switched type allowing data packets use a shared link for communication, thereby eliminating contention problems. This type suffers from a large variation in packet transfer delays when using multi-hop point to point connection. To overcome this drawback, a CDMA technique has been utilized in NOC.

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