ITT-2.1

C/C++ Compiler Support for Siemens TriCore DSP Instruction Set
Hao Shi, Roger Arnold, Karl Westerholz (Siemens Microelectronics, Inc)

How to make compilers more useful for developing DSP applications and reduce reliance on assembly coding has long been a topic of interest in the DSP community. This paper presents Siemens solutions for supporting its TriCore DSP/microcontroller architecture, including SIMD instructions, at the C/C++ level. Two solutions based on either extending C/C++ language with the new built-in DSP data types or developing an external DSP class library are investigated. First cut implementations of both methods have achieved 80% coverage of the TriCore instruction set, which is 30 percent higher than the coverage before DSP support was added.

ITT-2.2

A Simple, Non-Invasive Probe for Reconstructing Signals Inside a DSP
Edwin A. Suominen (Squire, Sanders and Dempsey, L.L.P.)

A simple, non-invasive probe is proposed that extracts digital samples of a signal of interest from a DSP and reconstructs the samples into an equivalent analog signal. The probe is useful for software design and debugging as well as troubleshooting and verification of DSP systems in the field. A sample buffering system ensures that the digital samples are reconstructed into analog at substantially constant intervals, even if the DSP generates the digital samples at varying intervals. The buffering system uses a control loop to generate the analog samples at a sample rate that is equivalent to the mean sample rate of the digital samples. Consequently, the reconstructed analog signal accurately represents the digital signal found within the DSP. This signal may then be sent to conventional test equipment suited for analysis of analog signals. Details beyond the scope of this paper may be found at http://eepatents.com/probe.

ITT-2.3

Source-Level Loop Optimization for DSP Code Generation
Bogong Su (Dept. of Computer Science, William Paterson University of New Jersey), Jian Wang (Real Time Speech Systems, Nortel Montreal Lab.), Andrew Esguerra (Dept. of Computer Science, William Paterson University of New Jersey)

The performance of current C compilers for DSP is almost unacceptable. One of the most important reasons is the lack of implementing software pipelining. This paper presents a remedy called source-level loop optimization. DSP programmers can use source-level loop optimization first then input its result to the DSP compiler to obtain better assembly code. The implementation of source-level loop optimization is easier than that of software pipelining. The preliminary result with the DSP compiler-challenge C code shows that source-level loop optimization is a portable and efficient approach. The detailed method and working examples are presented.

ITT-2.4

A Complete Development Environment for Image Processing Applications on Adaptive Computing Systems
Alan C Moorman, Donald M Cates (Khoral Research Inc.)

Adaptive computing has always been a topic of great interest, providing a means to automatically map an application to specific hardware. The hardware may be configured to a specific application, thereby providing optimal performance. However, the largest benefit is that this configuration may be performed optimally during program execution. Unfortunately, adaptive computing is a relatively new area of research, therefore imposing serious complications when developing applications for adaptive hardware. This problem limits ACS development to hardware experts, prohibiting application specialists, such as image processing experts, from utilizing these systems. This paper will discuss a development environment that can bring the world of ACS application development to the IP expert with minimal hardware knowledge.

ITT-2.5

A Floating-point to Integer C Converter with Shift Reduction for Fixed-point Digital Signal Processors
Ki-Il Kum, Jiyang Kang, Wonyong Sung (School of Electrical Engineering, Seoul National University)

A floating-point to integer C program translator is developed for convenient programming and efficient use of fixed-point programmable digital signal processors (DSP's). It not only converts data types and supports automatic scaling, but also conducts shift optimization to enhance execution speed. Since the input and output of this translator are ANSI C compliant programs, it can be used for any fixed-point DSP that supports ANSI C compiler. A shift reduction method is developed for minimizing the scaling overhead of translated integer C programs. It considers the data-path of a target processor and profiling results. Using the shift reduction method, 4% to 37 % speedup is obtained. The translated integer C codes are 20 to 400 times faster than the floating-point versions when applied to TMS320C50, TMS320C60 and Motorola 56000 DSP's.

ITT-2.6

Rapid Design of Discrete Orthonormal Wavelet Transforms using Silicon IP Components
Shahid Masud, John V McCanny (Queen's University of Belfast)

A rapid design methodology for orthonormal wavelet transform cores has been developed. This methodology is based on a generic, scaleable architecture utilising time-interleaved coefficients for the wavelet transform filters. The architecture has been captured in VHDL and parameterised in terms of wavelet family, wavelet type, data word length and coefficient word length. The control circuit is embedded within the cores and allows them to be cascaded without any interface glue logic for any desired level of decomposition. Case studies for stand alone and cascaded silicon cores for single and multi-stage wavelet analysis respectively are reported. The design time to produce silicon layout of a wavelet based system has been reduced to typically less than a day. The cores are comparable in area and performance to hand-crafted designs. The designs are portable across a range of foundries and are also applicable to FPGA and PLD implementations.

ITT-2.7

RAPID PROTOTYPING LIBRARY FOR ADAPTIVE SIGNAL PROCESSING APPLICATIONS
Timothy Bigg, John Owen (Entegra Ltd.), Robert W Stewart, Daniel Garcia-Alis, Moritz Harteneck, Marc Llovet-Vila (University of Strathclyde)

In this paper we present an adaptive signal processing library for the rapid prototyping of adaptive signal processing algorithms, architectures and applications. The library is hosted by the DSP simulation software SystemView and covers virtually the complete spectrum of linear, and non-linear adaptive algorithms currently in use in contemporary DSP and communications applications. The library can be easily used with real signals, with variable system wordlengths, sampling frequencies and so on. Therefore in this paper we will briefly discuss the design philosphy behind the library and present a number of rapidly developed adaptive algorithm simulations to demonstrate the library versatility. Simulations for active noise control, adaptive mobile channel DFEs (Decision Feedback Equalisers), adaptive multiuser CDMA (Code Division Multiple Access) receivers, and subband adaptive filters for acoustic echo control are discussed in this paper. Copies of the library and example files can be downloaded from the web following the instructions in the full paper.

ITT-2.8

Rapid Prototyping of Multimedia Chip Sets
Mohamed S Ben-Romdhane, Marius Vassiliou, Lan-Rong Dung (Rockwell Science Center)

We have developed a rapid prototyping environment for Multimedia applications. The design environment is based on efficient hardware and software reuse, abstraction, design parameterization, and automation. The design methodology maintains a flexible boundary between hardware and software by eliminating hardware fabrication from the design loop. A reusable Hardware/Software library for video compression has been developed to support the design methodology. We present a case study involving the design of an H.263-based video decoder. This case study illustrates the efficiency and flexibility of the design methodology.

ITT-2.9

An Interactive Tool for Bit Error Rate Analysis of Speech Coding Algorithms.
Hiren C Bhagatwala (Arizona State University), Edward M Painter (Airzona State University), Andreas S Spanias (Arizona State University)

A GUI-based software tool that provides a framework for evaluation of different speech coding algorithms is presented. The tool is designed to measure the susceptibility of speech coding algorithms to errors added on the encoded bit-stream during transmission. In particular, the errors can be added individually to each parameter that comprise the encoded bit-stream. This enables a designer of a speech codec to evaluate its performance under adverse or impaired channel conditions. Various features of this interactive software are described in this paper. The tool is designed to be universally applicable to different speech coding algorithms, by means of a bit-stream definition file. This interactive tool has been used for evaluation of a number of standardized speech coding algorithms. Results from this study are also presented.

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Last Update: February 4, 1999 Ingo Höntsch