Hierarchical designs

For our example, we will create an amplifier which we will break up into the power supply, the pre-amplifier block, and the power amplifier block. The power amplifier will also contain a hierarchical block for the load. The circuits we show will be fairly trivial and could easily be placed on a single schematic page. The point of this exercise is to show how to use the hierarchical tools available in Oread Capture. 

This is an advanced topic. We assume that the reader has already mastered creating schematics with Capture, running PSpice simulations, and plotting with Probe. All we will cover here is how to use the hierarchical tools. We will use many of the drawing tools covered earlier in this chapter without much explanation. 

We will start with a new empty project. Select File, New, and the Project from the menus  

Specify a name and directory for the file and click the OK button  

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Douglas, J. M., A Hierarchical Design Procedure for Process Synthesis, AlChEJ, 31 353, 1985. 

A hierarchical design procedure for process synthesis can be used in conjunction with a flow-sheeting program to analyze, evaluate, and optimize the options (60). The emphasis is on starting with the simplest possible models that will give answers to a particular question quickly so that the questions to be asked at the next decision level can be formulated. At each stage, it is necessary to ensure that the level of detail in the model is sufficient to give rehable information. 

Hierarchical Designs Based on Templating 4477 1.1. Drivers for 3-D Power ... 

This dialog box allows us to select a project template. A hierarchical design is one with many pages, and blocks that connect one page to another. We will choose to start with a bldflH project ... 

Next, we will look at the netlist created by this hierarchical design. Select PSpice and then Create Netlist from the Capture menus to create the netlist, and then select PSpice and then View Netlist to display the netlist ... 

The last thing we will do is look at the project tree for this hierarchical design. Switch back to Capture and select the... 

Hierarchic design of assembled structures should be important for preparation of functional mesoscopic structures. Typical examples can be seen in biological systems where tissues of organisms in living systems consist of assemblies of cells with cell membranes composed of self-assembled lipids, proteins, saccharides, etc. Therefore, tissues and organisms can be regarded as (at least) two-level assemblies lipid to... 

Mesoporous silica containers can be used as inhibitor hosts with controlled release properties triggered at the beginning of the corrosion process in response to local pH changes. For instance, mesoporous silica nanoparticles covered with polyelectrolyte layers can be loaded with an inhibitor (2-(benzothiazol-2-ylsulfanyl)-succinic acid) prior to introduction into a hybrid zirconia-silica sol-gel film. This hierarchical design avoids spontaneous release of the inhibitor by the formation of a polyelectrolyte shell over the container s outermost surface. 

Formally, the hierarchical design procedure can be divided in two steps process synthesis and process integration. The first deals with the synthesis of the process flowsheet and basic material balance. The second step handles the problem of efficient use of energy and helping material resources (water, solvents, hydrogen). Clearly, the two steps are interrelated. 

Fig. 16. Basic modeling elements in the HDL (hierarchical design language).

Many validation studies use a nested or hierarchical design (Figure 5). These studies usually involve several laboratories that independently conduct the same alternative method on all the substances in an RSTS. There are four sources of variability in such studies. These include variation in the test substances, variation within experiments within a laboratory (intraexperiment variability), variation between experiments within a laboratory (intralaboratory variability), and variation between laboratories (interlaboratory variability). Reviewed next is the nature and importance of each. The differences between chemicals are ignored in this discussion since they can generally be minimized with well-controlled test article distribution and storage. Attention is concentrated on the variability in results obtained by testing a single chemical in a number of different laboratories. 

Figure 5 Hierarchical design of a validation study. The different levels of repeated measures obtainable from assays tested in a validation study are shown. The descriptions on the left side indicate the names of the endpoints at each level, and the descriptions of the right side indicate the variability term associated with each level. Reproduced from Toxicology In Vitro 10 479-501,1996, Bruner, L. Proctor Gamble.

The Douglas hierarchical design decision procedures for analyzing flowsheets, particularly in the design of new processes ... 

In this chapter, emphasis is placed on the former approach of pinch technology. It is noteworthy that the mass integration concept incorporates the use of both approaches. Also, a notable work that combines the three approaches of hierarchical design via process simulation using the Aspen Plus commercial simulator, pinch technology, and mathematical programming is that of Dantus and High. ° ... 

Use Custom Data Structures with a Hierarchical Design... 

The objective of the 2.5-D placement problem is to map a cell netlist (pure standard cell or mixed macro/standard cell) to unique positions in a layered space as illustrated in Fig. 6.1. The inter-chip contacts are assumed to be placed on top of the chip with no need to consume substrate area. We need to differentiate two scenarios hierarchical and flattened design styles. In a hierarchical design set up, after the floorplanning step, cells in a block need to be placed. As mentioned in the last chapter, a random-logic based block could be split into two chips. The 2.5-D placement problem is to assign the cells within such a block to unique positions on two chips. On the other hand, in a flattened design style, the 2.5-D placement problem is to place both standard cell macros onto stacked chips. 

In this section, we consider the second scenario of 2.5-D placement, where a hierarchical design style is applied and the inter-chip contacts can be placed above the top-level metal layer. 

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