Inferring Complex Cells

In this section, we discuss certain common scenarios with regard to inferring complex cells. This helps one to understand the DesignWare mechanism and how it can be used to infer complex cells which are difficult to infer via synthesis. 

You have a certain cell available in your technology library, but DC does not infer this cell during synthesis. 

The crude, yet working solution is to instantiate the cell and dont Jouch the cell during synthesis. 

If DC does not infer a certain cell from the technology library, this is most likely due to one of the following reasons the Synopsys library does not have a function description for that cell, and hence, DC considers the cell as a black box, or the cell has a function attribute, but DC is incapable of mapping to this particular cell. 

You have several implementations of a certain datapath module (say an adder.) You wish to use a different implementation (the most appropriate with regard to speed and area) in each instance of an adder in the design. For example, you wish to use a cany select adder in one block, but a ripple carry implementation of the same adder in another. 

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The removable attribute indicates that Library Compiler knows what function the cell performs, so the cell can be replaced by a combination of other cells during synthesis and optimization. This attribute is usually attached to relatively complex cells, like adder cells, for example. These cells cannot be inferred by DC. 

The phorbol esters are useful for studying the function of PKC since they mimic the stimulatory effects of DAG on the enzyme. These tumor-promoting plant products and their synthetic derivatives are able to penetrate intact cells. Many inferences regarding the intracellular actions of PKC are based on results of studies on whole-cell preparations with the phorbol esters. These substances, like DAG, may produce feedback inhibition of signal transduction at a number of metabolic levels. Results of experiments using phorbol esters in whole cells are thus often complex and must be interpreted cautiously. Notwithstanding this consideration, based upon... 

Distantly related plants, such as rose, jasmin, and lavender have quite independently gone down this road of complexity, based on different groups of chemical constituents. We may conclude, therefore, that complexity of odor has evolved as being the most effective way of evoking a desired response from an animal with the ability to smell and the ability to memorize odor. What is remarkable is that the particular combinations of materials that individual flowers produce to make up their fragrance have, to our own sense of smell, an identity far greater than a random mixture of as many ill-assorted chemicals. Perhaps we may infer from this, in view of the similarity of our receptor cells, that the balance of materials is as important to the olfactory mechanism of the bee as it is to our own in producing a sense of identity and aesthetic pleasure. 

The obtained from the slope of vs. [cf. Eq. (2.95)] is near zero and it is inferred that this value indicates a value of zero for the translational entropy of the ion. A similar result was obtained for the solvated complex. Zero translational entropy for a solvated ion is a reasonable conclusion. Thus, for most of its time, the ion is still in a cell in the solution and only occasionally does it jump into a vacancy, or if it shuffles about, its movement is so constrained compared with that of a gas that it may approach zero. 

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