Efficient state reduction methods for PLA-based sequential circuits

Experiences with heuristics for the state reduction of finite-state machines are presented and two new heuristic algorithms described in detail. Results on machines from the literature and from the MCNC benchmark set are shown. The area of the PLA implementation of the combinational component and the design time are used as figures of merit. The comparison of such parameters, when the state reduction step is included in the design process and when it is not, suggests that fast state-reduction heuristics should be implemented within FSM automatic synthesis systems

Efficient realization of a threshold voter for self-purging redundancy

The self-purging technique is not commonly used mainly due to the lack of practical implementations of its key component, the threshold voter. A very efficient implementation of this voter is presented which uses a decomposition technique to substantially reduce the circuit complexity and delay, as compared to alternative implementations.Comisión Interministerial de Ciencia y Tecnología TIC97-064

RTD based logic circuits using generalized threshold gates

Many logic circuit applications of Resonant Tunneling Diodes are based on the MOnostable-BIstable Logic Element (MOBILE). Threshold logic is a computational model widely used in the design of MOBILE circuits, i.e. these circuits are built from threshold gates (TGs). The MOBILE realization of generalized threshold gates is being investigated. Multi-Threshold Threshold Gates (MTTGs) have been proposed which further increase the functionality of the original TGs. Recently, we have proposed a novel MOBILE circuit topology obtained by fundamental properties of threshold functions. This paper describes the design of n-bit adders using these novel MOBILE circuit topologies. A comparison with designs based on TGs and MTTGs is carried out showing advantages in terms of speed and power delay product and device counts.España, Gobierno TEC2007-67245Junta de Andalucía EXC/2007/TIC-296

Two-phase RTD-CMOS pipelined circuits

MOnostable-BIstable Logic Element (MOBILE) networks can be operated in a gate-level pipelined fashion (nanopipeline) allowing high through output. Resonant tunneling diode (RTD)-based MOBILE nanopipelined circuits have been reported using different clock schemes including a four-phase strategy and a single-phase clock scheme. In particular, significant power advantages of single-phase RTD-CMOS MOBILE circuits over pure CMOS have been shown. This letter compares the RTD-CMOS realizations using a single clock and a novel two-phase clock solution. Significant superior robustness and performance in terms of power and area are obtained for the two-phase implementations

Sorting networks implemented as νMOS circuits

A new realisation for n-input sorters is presented. Resorting to the neuron-MOS (νMOS) concept and to an adequate electrical scheme, a compact and efficient implementation is obtained.Comisión Interministerial de Ciencia y Tecnología TIC95-0094, TIC97-064

Astronomía y Universidad

Se comentan los momentos históricos en los que la Astronomía española ha progresado de forma más sobresaliente así como la contribución de las universidades a estos progresos en cada uno de ellos. Se distinguen cuatro etapas: Edad Media a partir del siglo X, época de la Ilustración, primeros años del siglo XX y segunda mitad de este mismo siglo XX.The hystorical periods when the Spanish Astronomy has advanced more notoriously and the contribution of the Universities in each period are commented. Four epochs are distinguished: Middle Age from the 10th century, Illustration, first years of the 20th century and second half of this 20th century.Es comenten les èpoques històriques en que l'Astronomia espanyola ha tingut els seus progessos més notables i la contribució de les universitats en cada una d'elles. Es distingueixen quatre etapes: Edat Mitjana a partir del segle X, anys de la llustració, primers anys del segle XX y segona meitat d'aquest mateix segle XX

A practical floating-gate Muller-C element using vMOS threshold gates

This paper presents the rationale for vMOS-based realizations of digital circuits when logic design techniques based on threshold logic gates are used. Some practical problems in the vMOS implementation of threshold gates have been identified and solved. The feasibility and versatility of the proposed technique as well as its potential as a low-cost design technique for CMOS technologies have been shown by experimental results from a multiple-input Muller C-element. The proposed new realization exhibits better performance related to delay and area and power consumption than the traditional logic implementation

Simplified single-phase clock scheme for MOBILE networks

MOBILE networks can be operated in a gate-level pipelined fashion allowing high through-output. If MOBILE gates are directly chained, a four-phase clock scheme is required for this. A single-phase scheme is possible adding latches to the MOBILE gates. Proposed and experimentally validated is a new single-phase interconnection scheme that simplifies the inter-stage element, which translates in power, area and clock load advantages with respect to using latches.Ministerio de Ciencia e Innovación TEC2007-67245, TEC2010-18937Junta de Andalucía TIC-296