DATA COMPRESSION USING EFFICIENT DICTIONARY SELECTION METHOD

With the increase in silicon densities, it is becoming feasible for compression systems to be implemented in chip. A system with distributed memory architecture is based on having data compression and decompression engines working independently on different data at the same time. This data is stored in memory distributed to each processor. The objective of the project is to design a lossless data compression system which operates in high-speed to achieve high compression rate. By using the architecture of compressors, the data compression rates are significantly improved. Also inherent scalability of architecture is possible. The main parts of the system are the data compressors and the control blocks providing control signals for the Data compressors, allowing appropriate control of the routing of data into and from the system. Each Data compressor can process four bytes of data into and from a block of data in every clock cycle. The data entering the system needs to be clocked in at a rate of 4 bytes in every clock cycle. This is to ensure that adequate data is present for all compressors to process rather than being in an idle state

A Geometric-Primitives-Based Compression Scheme for Testing Systems-on-a-Chip

The increasing complexity of systems-on-a-chip with the accompanied increase in their test data size has made the need for test data reduction imperative. In this paper, we introduce a novel and very efficient lossless compression technique for testing systems-on-a-chip based on geometric shapes. The technique exploits reordering of test vectors to minimize the number of shapes needed to encode the test data. The effectiveness of the technique in achieving high compression ratio is demonstrated on the largest ISCAS85 and full-scanned versions of ISCAS89 benchmark circuits. In this paper, it is assumed that an embedded core will be used to execute the decompression algorithm and decompress the test data

SoC Test: Trends and Recent Standards

The well-known approaching test cost crisis, where semiconductor test costs begin to approach or exceed manufacturing costs has led test engineers to apply new solutions to the problem of testing System-On-Chip (SoC) designs containing multiple IP (Intellectual Property) cores. While it is not yet possible to apply generic test architectures to an IP core within a SoC, the emergence of a number of similar approaches, and the release of new industry standards, such as IEEE 1500 and IEEE 1450.6, may begin to change this situation. This paper looks at these standards and at some techniques currently used by SoC test engineers. An extensive reference list is included, reflecting the purpose of this publication as a review paper

An Efficient Test Vector Compression Technique Based on Geometric Shapes

One of the prime challenges of testing a system-on-a-chip (SOC) is to reduce the required test data size. In this paper, we introduce a novel compression / decompression scheme based on geometric shapes that substantially reduces the amount of test data and reduces test time. The proposed scheme is based on ordering the test vectors in such a way that enables the generation of geometric shapes that can be highly compressed via perfect lossless compression. Experimental results on ISCAS benchmark circuits demonstrate the effectiveness of the proposed technique in achieving very high compression ratio. Compared to published results, our technique achieves significantly higher compression ratio

An Efficient Test Vector Compression Technique Based on Geometric Shapes

One of the prime challenges of testing a system-on-a-chip (SOC) is to reduce the required test data size. In this paper, we introduce a novel compression / decompression scheme based on geometric shapes that substantially reduces the amount of test data and reduces test time. The proposed scheme is based on ordering the test vectors in such a way that enables the generation of geometric shapes that can be highly compressed via perfect lossless compression. Experimental results on ISCAS benchmark circuits demonstrate the effectiveness of the proposed technique in achieving very high compression ratio. Compared to published results, our technique achieves significantly higher compression ratio

A high level test processor and test program generator

Embedded test within integrated systems allows to overcome some of the difficulties found when testing using only an external tester. The reutilization of a reconfigurable FPGA-like block that may exist in certain SoC systems, enables the implementation of on-chip test processors highly optimized to meet the specific requirements of the test procedure for each block. The fast reconfiguration of SRAM-based FPGA blocks allows sharing the same physical area among the set of different circuits that may be necessary to implement the on-chip test suite of the whole system. This paper addresses the high level generation of specific programmable processors for testing different blocks within integrated systems, taking advantage of such existing programmable resources. The work presented herein proposes a methodology and a set of automation tools to enable the automatic generation of dedicated custom processor architectures for specific test operations, as well as the corresponding test programs. This facility can be seen as disposing of a highly flexible and optimised embedded tester, supplied as an intellectual property (IP) module and its software. The approach being proposed is based in the implementation of a test processor as an Application Specific Instruction-Set Processor (ASIP), whose set of conventional and dedicated instructions are automatically derived from a software specification of the test operation to be implemented. The actual configuration of the test processor is determined by the type of instructions the test designer uses in the test program. The processors instruction set is configured automatically from the source code of the program to be run, in order to include only the exact instructions required for that task. The generation of a test processor starts with a software specification of the test operation to be performed. Presently, this specification is done using a program written in an assembly level language whose instruction set comprises all the general purpose instructions supported by the processor core, plus an extra set of complex instructions that are responsible for the operation of the peripheral specific blocks. From this specification, a custom programmable processor is generated as a set of synthesisable HDL modules, including the identification of peripheral blocks associated to specific instructions, and the set of constrains and assignments required to instantiate and map these modules onto the FPGA. These descriptions are then forwarded to the specific FPGA technology mapping and implementation tools, to create an application-specific processor that includes only the instructions referred in the source code