Using an FPGA for Fast Bit Accurate SoC Simulation

In this paper we describe a sequential simulation method to simulate large parallel homo- and heterogeneous systems on a single FPGA. The method is applicable for parallel systems were lengthy cycle and bit accurate simulations are required. It is particularly designed for systems that do not fit completely on the simulation platform (i.e. FPGA). As a case study, we use a Network-on-Chip (NoC) that is simulated in SystemC and on the described FPGA simulator. This enables us to observe the NoC behavior under a large variety of traffic patterns. Compared with the SystemC simulation we achieved a factor 80-300 of speed improvement, without compromising the cycle and bit level accuracy

Fast, Accurate and Detailed NoC Simulations

Network-on-Chip (NoC) architectures have a wide variety of parameters that can be adapted to the designer's requirements. Fast exploration of this parameter space is only possible at a high-level and several methods have been proposed. Cycle and bit accurate simulation is necessary when the actual router's RTL description needs to be evaluated and verified. However, extensive simulation of the NoC architecture with cycle and bit accuracy is prohibitively time consuming. In this paper we describe a simulation method to simulate large parallel homogeneous and heterogeneous network-on-chips on a single FPGA. The method is especially suitable for parallel systems where lengthy cycle and bit accurate simulations are required. As a case study, we use a NoC that was modelled and simulated in SystemC. We simulate the same NoC on the described FPGA simulator. This enables us to observe the NoC behavior under a large variety of traffic patterns. Compared with the SystemC simulation we achieved a speed-up of 80-300, without compromising the cycle and bit level accuracy

An AER Spike-Processing Filter Simulator and Automatic VHDL Generator Based on Cellular Automata

Spike-based systems are neuro-inspired circuits implementations traditionally used for sensory systems or sensor signal processing. Address-Event- Representation (AER) is a neuromorphic communication protocol for transferring asynchronous events between VLSI spike-based chips. These neuro-inspired implementations allow developing complex, multilayer, multichip neuromorphic systems and have been used to design sensor chips, such as retinas and cochlea, processing chips, e.g. filters, and learning chips. Furthermore, Cellular Automata (CA) is a bio-inspired processing model for problem solving. This approach divides the processing synchronous cells which change their states at the same time in order to get the solution. This paper presents a software simulator able to gather several spike-based elements into the same workspace in order to test a CA architecture based on AER before a hardware implementation. Furthermore this simulator produces VHDL for testing the AER-CA into the FPGA of the USBAER AER-tool.Ministerio de Ciencia e Innovación TEC2009-10639-C04-0

Implementation of a FFT/IFFT Module on FPGA: Comparison of Methodologies

In this work, we have compared three different methodologies for the implementation of a FFT/IFFT module on FPGA: VHDL coding (VC), System-level tools at RT level (STR), and System-level tools at macroblock level (STM). In terms of resource usage and operation frequency, STM has obtained interesting results, although it has an important restriction about internal data width which produces a mean output error of 2.1%. VC and STR become a more general alternative that yields to a lower mean error (1.0%). Thus, we propose to combine VC and STR in order to facilitate the design process as well as allow designers to maintain total control over the module internal architecture and obtain an efficient structure

A Cross-level Verification Methodology for Digital IPs Augmented with Embedded Timing Monitors

Smart systems implement the leading technology advances in the context of embedded devices. Current design methodologies are not suitable to deal with tightly interacting subsystems of different technological domains, namely analog, digital, discrete and power devices, MEMS and power sources. The interaction effects between the components and between the environment and the system must be modeled and simulated at system level to achieve high performance. Focusing on digital subsystem, additional design constraints have to be considered as a result of the integration of multi-domain subsystems in a single device. The main digital design challenges combined with those emerging from the heterogeneous nature of the whole system directly impact on performance, hence propagation delay, of the digital component. In this paper we propose a design approach to enhance the RTL model of a given digital component for the integration in smart systems, and a methodology to verify the added features at system-level. The design approach consists of ``augmenting'' the RTL model through the automatic insertion of delay sensors, which are capable of detecting and correcting timing failures. The verification methodology consists of an automatic flow of two steps. Firstly the augmented model is abstracted to system-level (i.e., SystemC TLM); secondly mutants, which are code mutations to emulate timing failures, are automatically injected into the abstracted model. Experimental results demonstrate the applicability of the proposed design and verification methodology and the effectiveness of the simulation performance

EXFI: a low cost Fault Injection System for embedded Microprocessor-based Boards

Evaluating the faulty behavior of low-cost embedded microprocessor-based boards is an increasingly important issue, due to their adoption in many safety critical systems. The architecture of a complete Fault Injection environment is proposed, integrating a module for generating a collapsed list of faults, and another for performing their injection and gathering the results. To address this issue, the paper describes a software-implemented Fault Injection approach based on the Trace Exception Mode available in most microprocessors. The authors describe EXFI, a prototypical system implementing the approach, and provide data about some sample benchmark applications. The main advantages of EXFI are the low cost, the good portability, and the high efficienc

Protocol-Inspired Hardware Testing

The relevance of protocol conformance testing techniques to hardware testing is discussed. It is shown that the ioconf (input-output conformance) approach used in protocol testing can be applied to generate tests for a synchronous hardware design using its formal specification. The generated tests are automatically applied to a circuit by a VHDL testbench, thus giving confidence that the hardware design meets its high-level formal specification. Case studies illustrate how the ideas can be applied to standard hardware verification benchmarks such as the Single Pulser and Black-Jack Dealer

Functional Verification of Large-integers Circuits using a Cosimulation-based Approach

Cryptography and computational algebra designs are complex systems based on modular arithmetic and build on multi-level modules where bit-width is generally larger than 64-bit. Because of their particularity, such designs pose a real challenge for verification, in part because large-integer’s functions are not supported in actual hardware description languages (HDLs), therefore limiting the HDL testbench utility. In another hand, high-level verification approach proved its efficiency in the last decade over HDL testbench technique by raising the latter at a higher abstraction level. In this work, we propose a high-level platform to verify such designs, by leveraging the capabilities of a popular tool (Matlab/Simulink) to meet the requirements of a cycle accurate verification without bit-size restrictions and in multi-level inside the design architecture. The proposed high-level platform is augmented by an assertion-based verification to complete the verification coverage. The platform experimental results of the testcase provided good evidence of its performance and re-usability

Python based FPGA design-flow

This dissertation undertakes to establish the feasibility of using MyHDL as a basis on which to develop an FPGA-based DSP tool-ow to target CASPER hardware. MyHDL is an open-source package which enables Python to be used as a hardware definition and verification language. As Python is a high-level language, hardware designers can use it to model and simulate designs, without needing detailed knowledge of the underlying hardware. MyHDL has the ability to convert designs to Verilog or VHDL allowing it to integrate into the more traditional design-ow. The CASPER tool- ow exhibits limitations such as design environment instability and high licensing fees. These shortcomings are addressed by MyHDL. To enable CASPER to take advantage of its powerful features, MyHDL is incorporated into a next generation tool-ow which enables high-level designs to be fully simulated and implemented on the CASPER hardware architectures