Introduction

1. Micorelectronics and Information Technology System of Interest • Introduction • Traditionally, busses have been used to interconnect IP-blocks. This is quite effective for a small number of communicating units, but as the number of units increases, especially on a SoC, more competition for the bus arises as well as having long undesirable on-chip interconnects. • The NoC approach emerged as a promising solution because of its good scalability characteristics. However, this technique is quite new and not much is known about how real systems would perform if implemented using NoCs. • In this project we implemented a simple network in C representing the basis of a router on chip, in order to study the performance of such a system. µsec Performance Analysis of a NoC Router-on-Chip August 30, 2004 Kista, Sweden Supervisors: Dr. Johnny Öberg, Iyad Al Khatib, and Professor Axel Jantsch Training Student: Linda Haydamous,Faculty of Engineering and Architecture (FEA) American University of Beirut (AUB) http://www.aub.edu Royal Institute of Technology Stockholm, Sweden Arrival Event DepartureEvent ta td Arrival and departure timestamps NoC Mesh Architecture S S R R Resource Resource S S R R Resource Resource Results Nostrum Backbone NxM NoC Service Time NoC IP Router Service Time formula:Sn = So + (n-1) r where, n = (IP_Payload(in bytes) – 8B(UDP header))/32B; Sn = service time (µsec) for a packet with IP payload of (32n+8)B = general sequence term; So = original service-time (µsec) for a packet with 40B IP payload = sequence first-term (S1); r = incremental difference in µsec (calculated from linear regression of average service-time values of different payloads) = sequence common difference; Service Time formula in terms of payload: Nostrum Backbone Throughput For our network, the service time formula was calculated to be: If there are n nodes between the sending and the receiveing units, the throughput becomes: where Siis the service-time delay in node i. The throughput can be parameterized in terms of payload as: where, So-i = The original service time of node i on the NoC path from node 1 (being the first node on the path after the sender) to n (being the last node on the path before the receiver). The delay is measured in microseconds since we are using the program on a pc. Hence, the operating system relatively large time scales are reflected in the microsecond scale. If it was implemented on a real NoC, the delay would be in different and expressed nanoseconds. However, we believe that proportionality could be built between the PC simulation and the real NoC so that the nanosecond delays could be induced from the simulation. This is part of the future work. Laboratory of Electronics and Computer Systems (LECS) Department of Microelectronics and Information Technology (IMIT) http://www.imit.kth.se/ Royal Institute of Technology (KTH), Stockholm, Sweden Trainee E-mail: lah05@aub.edu.lb