The Super Harvard Architecture Single-Chip Computer (SHARC) is a high performance floating-point and fixed-point DSP from Analog Devices. SHARC is used. Check out the SHARC Processor page at Sweetwater — the world’s leading The Analog Devices Super Harvard Architecture Single-Chip. The SHARC Processor portfolio currently consists of three generations of products SIMD architecture with integrated application-specific system peripherals.
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Subscribe to the Embedded Insights Newsletter to be notified architectuure directory updates. Many instructions are conditional, and may be preceded with “if condition ” in the assembly language.
This avoids needing to use precious CPU clock cycles to keep track of how the data are stored. The SHARC is a Harvard architecture word-addressed VLIW processor; it knows nothing of 8-bit or bit values archihecture each address is used to point to a whole bit word, not just an octet. For instance, an 80 bit accumulator is built into the multiplier to reduce the round-off error associated with arcyitecture fixed-point math operations.
This is a small memory that contains about 32 of the most recent program instructions. As shown in this illustration, Aiken insisted on separate memories for data and program instructions, with separate buses for each. From Wikipedia, the free encyclopedia. This leads us to the Harvard architectureshown in b. In fact, most computers today are of the Von Neumann design.
Von Neumann guided the mathematics of many important discoveries of the early twentieth century. This results in slower operation because of the conflict with the coefficients that must also be fetched along this path. Multiple stages require multiple circular buffers for orocessor fastest operation. Please improve this by adding secondary or tertiary sources. This includes datasuch as samples from the input signal and the filter coefficients, as well as program instructionsthe binary codes that go into the program sequencer.
We only need architecyure architectures when very fast processing is required, and we are willing to pay the price of increased complexity. Now we come to the critical performance of the architecture, how many of the operations within the loop steps of Table can be carried out at the same time.
Code and data are normally fetched from architectuge memory, which the user must split proceseor regions of different word sizes as desired.
The main buses program memory bus and data memory bus are also accessible from outside the chip, providing an additional interface to off-chip memory and peripherals. These products also integrate a variety of ROM memory configurations and audio-centric peripherals design to decrease time to market and reduce the overall bill of materials costs.
Most memory-related CPU instructions can not access all the bits of bit memory, but a special bit register is provided for this purpose. Figure a shows how this seemingly simple task is done in a traditional microprocessor. First, let’s look at how the instruction cache improves the performance of the Harvard architecture. Some DSPs have on-board analog-to-digital and digital-to-analog converters, a feature called mixed signal. However, on additional executions of the loop, the program instructions can be pulled from the instruction cache.
SHARC processors are or were used because they have offered good floating-point performance per watt. For instance, IIR filters are more stable if implemented as a cascade of biquads a stage containing two poles and up to two zeros. A DMA engine is provided for this.
Code can instantly switch between them, allowing for fast context switches between an processof and an OS or between two threads. How to order your own hardcover wharc Wouldn’t you rather have a bound book instead of loose procesdor There will be extra clock cycles associated with beginning archiecture ending the loop steps 3, 4, 5 and 13, plus moving initial values into place ; however, these tasks are also handled very efficiently.
In simpler microprocessors this task is handled as an inherent part of the program sequencer, and is quite transparent to the programmer. If the off-chip memory is configured as bit words to avoid waste, then only the on-chip memory may be used for code execution and extended floating-point.
If the loop is executed more than a few times, this overhead will be negligible. Up to 6 levels may be used, avoiding the need for normal branching instructions and the normal bookkeeping related to loop exit.
Figure c illustrates the next level of sophistication, the Super Harvard Architecture. SHARC processors include audio-specific and general-purpose peripherals. Neural Networks and more!
Architecture of the Digital Signal Processor
Since the buses operate independently, program instructions and data can be fetched at the same time, improving the speed over the single bus design. The special bit register may be accessed as a pair of smaller registers, allowing movement to and from the architecturw registers. However, DSPs are designed to operate with circular buffersand benefit from the extra hardware to manage them efficiently.
If needed, these registers can also be used to control loops and counters; however, the SHARC DSPs have extra hardware registers to carry out many of these functions. These are duplicate registers that can be switched with their counterparts in a single clock cycle.
For instance, we might place the filter coefficients in program memory, while keeping the input signal in data memory. The data register section of the CPU is used in the same way as in traditional microprocessors. Analog Devices chose to avoid the issue by using a prkcessor char in their C compiler.
SHARC Processor Architectural Overview
Analog Devices’ SHARC processor family targets processoe ranging from consumer, automotive, and professional audio, to industrial, test and measurement, and medical equipment. To improve upon this situation, we start by relocating part of the “data” to program memory. Most present day DSPs use this dual bus architecture. September Learn how and when to remove this template message. This means that each DAG holds 32 variables 4 per bufferplus the required logic. In fact, if we were executing random instructions, this situation would be no better at all.
This capability is especially relevant in consumer, automotive, and professional audio where the algorithms related to stereo channel processing can effectively utilize the SIMD architecture. Small data types may be stored in wider memory, simply wasting the extra space.
However, all DSPs can interface with external converters through serial or parallel ports. There are also many important features of the SHARC family architecture that aren’t shown in this simplified illustration. In addition, an abundance of circular buffers greatly simplifies DSP code generation- both for the human programmer as well as high-level language pgocessor, such as C.