Library design and redesign

Fig. 2. Schematic of the Monte Carlo library design and redesign strategy (from Falcioni and Deem, 2000). (a) One Monte Carlo round with 10 samples an initial set of samples, modification of the samples, measurement of the new figures of merit, and the Metropolis criterion for acceptance or rejection of the new samples, (b) One parallel tempering round with five samples at and five samples at f>2- In parallel tempering, several Monte Carlo simulations are performed at different temperatures, with the additional possibility of sample exchange between the simulations at different temperatures.

On top of this, vendors supply libraries that contain circuit modules or macros that are designed to make die most efficient use of the resources in a particular technology or actual device. These modules can be instantiated as components. The drawback of vendor libraries is that the VHDL description is technology dependent and to target a different technology can involve a considerable redesign effort. The macro / module approach is particularly valuable for PPG A devices that have available a limited number of fixed function resources. 

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