A Photonic Network on Chip with CDMA Links Soumyajit Poddar, Prasun Ghosal, Priyajit Mukherjee, Suman Samui, and Hafizur Rahaman Bengal Engineering and Science University, Shibpur Howrah 711103, WB, India {poddar18,priyajit.sp,samuisuman}@gmail.com, prasun@ieee.org, rahaman h@yahoo.co.in Abstract. Currently, photonic network on chips utilize dense wave- length division multiplexing by modulating multiple high bandwidth wavelength channels from an on-chip broadband LASER source. We use adaptive Code Division Multiple Access techniques with the above method to allocate a single wavelength channel to multiple transceivers, each one being allocated a unique PN code. Keywords: CDMA, On-chip communication, Photonic NoC. 1 Introduction Photonic interconnect promises to deliver bandwidth in tens of Gigabits per sec- ond (10Gbps) with Bit Error Rate (BER) many orders below wired and wireless interconnect. However if Dense Wave-length Division Multiplexing (DWDM) is used, then aggregate bandwidths of several 100s of Gbps can be obtained. The major limitation of photonic interconnects is the large area required and also limited broadcast ability. In this paper we have proposed a solution that needs a fraction of the area required in previous photonic NoCs. 2 Architecture of the Proposed Network on Chip This work uses Code Division Multiple Access Techniques [1] in addition to photonic interconnect. Such an approach results in a very simple ring topology and hence the number of micro rings is reduced to less than hundred. This directly translates to a fraction of the area requirement of previous approaches. Our Network on Chip is a 3D chip with two layers (Physical plane) stacked one on top of the other communicating via TSVs. The physical plane contains IP cores and their communication resources. The routing plane consists of both wavelength division multiplexed photonic interconnect and its related electrical backend. Local communication refers to intra-cluster traffic and global commu- nication refers to inter-cluster traffic. Intra cluster traffic takes place by means of the Mesh network in the logical plane while inter cluster traffic takes place with the help of the CDMA photonic interconnect on the routing plane. The proposed H. Rahaman et al. (Eds.): VDAT 2012, LNCS 7373, pp. 377–378, 2012. c  Springer-Verlag Berlin Heidelberg 2012