Systems on chip (SOC) are composed of intellectual property blocks (IP) and interconnect. While mature tooling exists to design the former, tooling for interconnect design is still a research area. In this paper we describe an operational design flow that generates and configures application-specific network on chip (NOC) instances, given application communication requirements. The NOC can be simulated in SystemC and RTL VHDL. An independent performance verification tool verifies analytically that the NOC instance (hardware) and its configuration (software) together meet the application performance requirements. The Æthereal NOC's guaranteed performance is essential to replace time-consuming simulation by fast analytical performance validation. As a result, application-specific NOCs that are guaranteed to meet the application's communication requirements are generated and verified in minutes, reducing the number of design iterations. A realistic MPEG SOC example substantiates our claims.

We present a network interface (NI) for an on-chip network. Our NI decouples computation from communication by offering a shared-memory abstraction, which is independent of the network implementation. We use a transaction-based protocol to achieve backward compatibility with existing bus protocols such as AXI, OCP, and DTL. Our NI has a modular architecture, which allows flexible instantiation. It provides both guaranteed and best-effort services via connections. These are configured via NI ports using the network itself, instead of a separate control interconnect. An example instance of this NI with four ports has an area of 0.25 mm/sup 2/ after layout in 0.13-/spl mu/m technology, and runs at 500 MHz.

A challenge facing designers of systems on chip (SoC) containing networks on chip (NoC) is to find NoC instances that balance the cost (e.g. area) and performance (e.g. latency and throughput). In this paper we present a simulation-based approach to address this problem. We use XML to instantiate network components (routers, network interfaces) and their composition. NoCs are evaluated in terms of cost and performance by sweeping over different parameters (e.g. network topology, network interface queue depth). We then show, how we can obtain trade-off plots by using the results obtained with our simulation environment. Finally, by means of two examples we illustrate how trade-off plots can help the NoC designers in selecting the right network based on a set of different constraints.

In this paper we present a network interface for an on-chip network. Our network interface decouples computation from communication by offering a shared-memory abstraction, which is independent of the network implementation. We use a transaction-based protocol to achieve backward compatibility with existing bus protocols such as AXI, OCP and DTL. Our network interface has a modular architecture, which allows flexible instantiation. It provides both guaranteed and best-effort services via connections. These are configured via network interface ports using the network itself, instead of a separate control interconnect. An example instance of this network interface with 4 ports has an area of 0.143 mm/sup 2/ in a 0.13 /spl mu/m technology, and runs at 500 MHz.

High level modeling and (quantitative) performance analysis of signal processing systems requires high level models for the applications (algorithms) and the implementations (architecture), a mapping of the former into the latter and a simulator for fast execution of the whole. Signal processing algorithms are very often nested-loop algorithms with a high degree of inherent parallelism. This paper presents-for such applications-suitable application and implementation models, a method to convert a given imperative executable specification to a specification in terms of the application model, a method to map this specification into an architecture specification in terms of the implementation model, and a method to analyze the performance through simulation. The methods and tools ore illustrated by means of an example.

In this paper we present a strategy for determining a dataflow processor which is intended for the execution of Jacobi algorithms which are found in the application domain of array processing and other real-lime adaptive signal processing applications. Our strategy to determine a processor for their execution is to exploit the quasi regularity property in their dependence graph representations in search for what we call the Jacobi processor. This processor emerges from an exploration iteration which takes off from a processor template and a set of Jacobi algorithms. Based on qualitative and quantitative performance analysis, both the algorithms and the processor template are restructured towards improved execution performance. To ensure the mapper is part of the emerging processor specification, the algorithm-to-processor mapping method is included in the iterative and hierarchical exploration method. Processor's hierarchy exploits properties related to regularity in the algorithm's structure, allows gentle transitions from regular to irregular levels in the algorithm hierarchy and offers different control models for the irregular structures that appear at deeper levels of the hierarchy. Transformations aiming at reducing critical paths, increasing throughput, improving mapping efficiency and minimizing control and flow overheads are essential. They include retiming, pipelining and lookahead techniques.