Making VHDL a simple and easy-to-use hardware description language

Many engineers encountering VHDL (very high speed integrated circuits hardware description language) for the first time can feel overwhelmed by it. This book bridges the gap between the VHDL language and the hardware that results from logic synthesis with clear organisation, progressing from the basics of combinational logic, types, and operators; through special structures such as tristate buses, register banks and memories, to advanced themes such as developing your own packages, writing test benches and using the full range of synthesis types.

This third edition has been substantially rewritten to include the new VHDL-2008 features that enable synthesis of fixed-point and floating-point hardware. Extensively updated throughout to reflect modern logic synthesis usage, it also contains a complete case study to demonstrate the updated features.

Features to this edition include: a common VHDL subset which will work across a range of different synthesis systems, targeting a very wide range of technologiesa design style that results in long design lifetimes, maximum design reuse and easy technology retargeting a new chapter on a large scale design example based on a digital filter from design objective and design process, to testing strategy and test benchesa chapter on writing test benches, with everything needed to implement a test-based design strategyextensive coverage of data path design, including integer, fixed-point and floating-point arithmetic, logic circuits, shifters, tristate buses, RAMs, ROMs, state machines, and decoders

Focused specifically on logic synthesis, this book is for professional hardware engineers using VHDL for logic synthesis, and digital systems designers new to VHDL but familiar with digital systems. It offers all the knowledge and tools needed to use VHDL for logic synthesis. Organised in themed chapters and with a comprehensive index, this complete reference will also benefit postgraduate students following courses on microelectronics or VLSI/ semiconductors and digital design.

The separation of finely-divided solids from liquids constitutes an important stage in many industrial processes. Separation of mixtures ranging from highly concentrated slurries to slightly turbid liquids must be effected in circumstances where the solids, liquid or both phases may have value. Separations may be achieved by use of a membrane or filter medium which, positioned in the path of a flowing suspension, will allow passage of the fluid whilst retaining solids on the surface or within the medium. Alternatively the two phases may be separated by sedimentation processes involving gravitational or centrifugal force. In either mode, separation difficulties are sometimes experienced with the result that solid-liquid separation is often a bottleneck in commercial plants. Operational difficulties and plant failures are associated with the random nature of the particles being separated; variations in size, shape, states of aggregation, compressibility, etc. , produce a wide range of problems. Plugging of the filter medium or the collapse of the solids under applied stress lead to slow flowrates of liquid. The colloidal nature of some precipitates makes separation by settling virtually impossible without the use of chemical agents to enhance the size of basic units and to reduce repulsive surface forces. Unit operations such as filtration, comminution, etc. , involve a seemingly bewildering array of machines which makes plant selection a difficult step and reflects the uncer tainties attaching to operations involving the solid )hase. Many types of pressure, vacuum and centrifugal filter are available.

The separation of finely-divided solids from liquids constitutes an important stage in many industrial processes. Separation of mixtures ranging from highly concentrated slurries to slightly turbid liquids must be effected in circumstances where the solids, liquid or both phases may have value. Separations may be achieved by use of a membrane or filter medium which, positioned in the path of a flowing suspension, will allow passage of the fluid whilst retaining solids on the surface or within the medium. Alternatively the two phases may be separated by sedimentation processes involving gravitational or centrifugal force. In either mode, separation difficulties are sometimes experienced with the result that solid-liquid separation is often a bottleneck in commercial plants. Operational difficulties and plant failures are associated with the random nature of the particles being separated; variations in size, shape, states of aggregation, compressibility, etc. , produce a wide range of problems. Plugging of the filter medium or the collapse of the solids under applied stress lead to slow flowrates of liquid. The colloidal nature of some precipitates makes separation by settling virtually impossible without the use of chemical agents to enhance the size of basic units and to reduce repulsive surface forces. Unit operations such as filtration, comminution, etc. , involve a seemingly bewildering array of machines which makes plant selection a difficult step and reflects the uncer tainties attaching to operations involving the solid )hase. Many types of pressure, vacuum and centrifugal filter are available.

This book is about the drugs used in the treatment and management of rheumatic disorders. The term 'therapeutics' used in the title is intended to mirror the relevance of drugs in the widest sense of the word. Thus, general principles underlying pharmaceutical and pharmacological study have been included together with more clinical matters concerned with applying specific rheumatic problems. The need for another work on rheumatological drugs in itself, as opposed to the different approach intended, was prompted by the ever continuing and bewildering plethora of antirheumatic drugs flooding the market at present. We believe that such a burgeoning of new preparations is welcome in an era when in general there are still no 'cures' available. Moreover, we also feel that a continued update of this rapidly advancing field is essential, not only for its own sake, but also to place it in perspective with itself and with neighbouring fields.