Behavioral Synthesis Design Flow

BC accepts both VHDLand Verilog. The behavioral HDL description is converted to an intermediate database, the Synopsys db format. In effect, an HDL written at higher level of abstraction is converted to multiple RTL implementations using behavioral synthesis. All the information about constraints and multi-cycle operations are 

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Chapter 3 covers the simulation steps, i.e., both functional or behavioral simulation of the HDL and the post-sfynthesis or gate-level simulation. This chapter has been included, primarily, to help the reader understand the design flow better. An example VHDL code of TAP controller is provided along with its testbench. The steps to perform behavioral simulation, and gate level simulation after synthesis have been discussed. The simulator used here is the Synopsys VHDL System Simulator (VSS). However, discussion on VSS is beyond the scope of this book. 

G. Borriello. Combining Event and Data-Flow Graphs in Behavioral Synthesis. Proceedings of the IEEE International Conference on Computer-Aided Design (ICCAD 88), November 1988. 

Gas-liquid bubble columns and gas-liquid-solid slurry bubble columns are widely used in the chemical and petrochemical industries for processes such as methanol synthesis, coal liquefaction, Fischer-Tropsch synthesis and separation methods such as solvent extraction and particle/gas flotation. The hydrodynamic behavior of gas-liquid bubble columns and gas-liquid-solid slurry bubble columns are of great importance for the design and scale-up of reactors. Although the hydrodynamics of the bubble and slurry bubble columns has been a subject of intensive research through experiments and computations, the flow structure quantification of complex multi-phase flows are still not well understood, especially in the three-dimensional region. In bubble and slurry bubble columns, the presence of gas bubbles plays an important role to induce appreciable liquid/solids mixing as well as mass transfer. The flows within these systems are divided into two... 

The results above indicate clearly that the presence of flow rates of different magnitudes (a steady-state design feature of many process systems) impacts upon the dynamic behavior of the process. In what follows, we further our analysis by emphasizing the implications of steady-state design on the selection of control structures and the synthesis of well-conditioned controllers for the class of processes considered. 

In the use of radioactive tracers it is assumed that the radioactive isotopes studied are identical in chemical behavior to the nonradioactive isotopes. The first experiments that used radioactive tracers were carried out in 1913 in Germany and were designed to measure the solubility of lead salts via the use of a radioactive isotope of lead. In industry, radionuclides have been used for analytical purposes, for measurements of flow in pipes, and as part of many other apphcations. Another example of an important tracer study has been the investigation of photosynthesis of carbohydrates from atmospheric CO2 in the presence of light and chlorophyll. Scientists used eC, 15P, and iH to identify the intermediate steps involved in the photosynthesis of carbohydrates in plants that had been placed in an atmosphere composed of fyC-labeled CO2 and had been irradiated with hght. The presence of the radioactive carbon in the synthesized carbohydrate was evidence that O2 was involved in the synthesis. 

Unlike many designer-oriented specifications, data flow graphs are semantically clean and simple, thus forming an unambiguous behavioral definition suitable to interface to or exchange between synthesis packages, as well as to formal verification. 

Each phase solves one or more subproblems in synthesis. The phases communicate with each other through internal behavioral descriptions which are either TOOL syntax trees or data flow graphs. Each phase transforms, annotates or translates its input. LISP property lists, the primary communication mechanism between phases, are used to record descriptions of design decisions and design analyses. Information recorded by earlier phases is kept as long as it is needed by later phases. 

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