28-12-2010, 01:03 PM
Tiger SHARC Processor.doc (Size: 347.5 KB / Downloads: 67)
ABSTRACT
The Tiger SHARC processor is the newest and most power member of this family which incorporates many mechanisms like SIMD, VLIW and short vector memory access in a single processor. This is the first time that all these have been combined in a real time processor.
The TigerSHARC DSP is an ultra high performance static superscalar architecture that optimized for tele-communications infrastructure and other computationally demanding applications.
The unique architecture combines elements of RISC, VLIW and standard DSP processors to provide native support for 8, 16,and 32-bit fixed, as well as floating point data types on single chip. Large on-chip memory, extremely high internal and external bandwidths and dual compute blocks provide the necessary capabilities to handle a vast array of computationally demanding, large signal processing tasks.
INTRODUCTION
1.1 Analog and digital signals
In many cases, the signal of interest is initially in the form of an analog electrical voltage or current, produced for example by a microphone or some other type of transducer. An analog signal must be converted into digital form before DSP techniques can be applied. An analog electrical voltage signal, for example, can be digitized using an electronic circuit called an analog-to-digital converter or ADC. This generates a digital output as a stream of binary numbers whose values represent the electrical voltage input to the device at each sampling instant.
1.2 Signal processing
Signals commonly need to be processed in a variety of ways. For example, the output signal from a transducer may well be contaminated with unwanted electrical "noise". The electrodes attached to a patient's chest when an ECG is taken measure tiny electrical voltage changes due to the activity of the heart and other muscles. The signal is often strongly affected by "mains pickup" due to electrical interference from the mains supply. Processing the signal using a filter circuit can remove or at least reduce the unwanted part of the signal. Increasingly nowadays, the filtering of signals to improve signal quality or to extract important information is done by DSP techniques rather than by analog electronics.
1.3 Digital Signal Processing
Digital signal processing (DSP) is the study of signals in a digital representation and the processing methods of these signals. DSP and analog signal processing are subfields of signal processing Digital Signal Processing is carried out
by mathematical operations. In comparison, word processing and similar programs merely rearrange stored data. This means that computers designed for business and other general applications are not optimized for algorithms such as digital filtering and Fourier analysis. Digital Signal Processors are microprocessors specifically designed to handle Digital Signal Processing tasks. These devices have seen tremendous growth in the last decade, finding use in everything from cellular telephones to advanced scientific instruments. In fact, hardware engineers use "DSP" to mean Digital Signal Processor, just as algorithm developers use "DSP" to mean Digital Signal Processing
1.4 Development of DSP
The development of digital signal processing dates from the 1960's with the use of mainframe digital computers for number-crunching applications such as the Fast Fourier Transform (FFT), which allows the frequency spectrum of a signal to be computed rapidly. These techniques were not widely used at that time, because suitable computing equipment was generally available only in universities and other scientific research institutions.
1.5 Digital Signal Processors (DSPs)
DSP processors are microprocessors designed to perform digital signal processing- the mathematical manipulation of digitally represented signals. The introduction of the microprocessor in the late 1970's and early 1980's made it possible for DSP techniques to be used in a much wider range of applications. However, general-purpose microprocessors such as the Intel x86 family are not ideally suited to the numerically-intensive requirements of DSP, and during the 1980's the increasing importance of DSP led several major electronics manufacturers
(such as Texas Instruments, Analog Devices and Motorola) to develop Digital Signal Processor chips - specialised microprocessors with architectures designed specifically for the types of operations required in digital signal processing. (Note that the acronym DSP can variously mean Digital Signal Processing, the term used for a wide range of techniques for processing signals digitally, or Digital Signal Processor, a specialised type of microprocessor chip). Like a general-purpose microprocessor, a DSP is a programmable device, with its own native instruction code. DSP chips are capable of carrying out millions of floating point operations per second, and like their better-known general-purpose cousins, faster and more powerful versions are continually being introduced. DSPs can also be embedded within complex "system-on-chip" devices, often containing both analog and digital circuitry.
Advantage over other Microprocessors
• Single cycle multiply-accumulate operations(MAC)
• Real time performance
• Flexibility and Reliability
• Increased system performance
• Reduced cost
• Harvard architecture