Layout area models for high-level synthesis

Traditionally, the common cost functions, the number of functional units, registers and selector inputs, are used in high level synthesis as quality measures. However, these traditional design quality measures may not reflect the real physical design. To establish quality measures based on the physical designs, we propose layout estimation models for two commonly used data path and control layout architectures. The results show that quality measures deriving from our models give an accurate prediction of the final layout. The results also show that traditional cost functions are not good indicators for optimization in high level synthesis

On evolution of relatively large combinational logic circuits

Evolvable hardware (EHW) (Yao and Higuchi, 1999) is a technique introduced to automatically design circuits where the circuit configuration is carried out by evolutionary algorithms. One of the main difficulties in using EHW to solve real-world problems is the scalability. Until now, several strategies have been proposed to avoid this problem, but none of them completely tackle the issue. In this paper three different methods for evolving the most complex circuits have been tested for their scalability. These methods are bi-directional incremental evolution (SO-BIE); generalised disjunction decomposition (GD-BIE) and evolutionary strategies (ES) with dynamic mutation rate. In order to achieve the generalised conclusions the chosen approaches were tested using multipliers, traditionally used in EHW, but also logic circuits taken from MCNC (Yang, 1991) benchmark library and randomly generated circuits. The analysis of the approaches demonstrated that PLA-based ES is capable of evolving logic circuits of up to 12 inputs. The use of SO-BIE allows the generation of fully functional circuits of 14 inputs and GD-BIE is estimated to be able to evolve circuits of 21 inputs

Genetic algorithm approach to find the best input variable partitioning

Conference PaperThis paper presents a variable partition algorithm which combines the quasi-reduced ordered multiple-terminal multiple-valued decision diagrams and genetic algorithms (GAs). The algorithm is better than the previous techniques which find a good functional decomposition by non-exhaustive search and expands the range of searching for the best decomposition providing the optimal subtable multiplicity. The possible solutions are evaluated using the gain of decomposition for a multiple-output multiple-valued logic function. The distinct feature of GA is the possible solutions being coded by real numbers. Here the simplex-based crossover is proposed to use for the recombination stage of GA. It permits to increase the GA coverag

Improving EHW performance introducing a new decomposition strategy

This paper describes a new type of decomposition strategy for Evolvable Hardware, which tackles the problem of scalability. Several logic circuits from the MCNC benchmark have been evolved and compared with other Evolvable Hardware techniques. The results demonstrate that the proposed method improves the evolution of logic circuits in terms of time and fitness function in comparison with BIE and standard EHW

SLIM: A Language for Microcode Description and Simulation in VLSI

SLIM (Stanford Language for Implementing Microcode) is a programming language based system for specifying and simulating microcode in a VLSI chip. The language is oriented towards PLA implementations of microcoded machines using either a microprogram counter or a finite state machine. The system supports simulation of the microcode and will drive a PLA layout program to automatically create the PLA