DOI:10.1049/ip-e.1980.0003

出版商:IEE    

年代:1980

数据来源: IET

DOI:10.1049/ip-e.1980.0004

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The checking of geometrical constraints on integrated-circuit layouts is notoriously slow and costly when carried out purely by software. This paper introduces a new approach, in which layers are converted into digitised pictorial form and processed by simple hardware operating like a computer peripheral. This hardware reports to the computer all cases where constraints may be violated, and these cases are investigated in detail purely by software. The advantage of this approach is the reduction in the total amount of c.p.u. time required for constraint checking.

DOI:10.1049/ip-e.1980.0005

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The fast Fourier transform (f.f.t.) has found wide applications in areas requiring the processing of uniformly sampled signals. This paper investigates the characteristics of using a standard, inexpensive micro-computer system to implement an f.f.t. processor operating in either real-time or online mode. Various aspects on the maximum sampling rate in either mode of operation, such as the limitation by the system input/output time and f.f.t. computation time, as well as the aliasing-free condition to process bandlimited periodic signals, are revealed. The sampling clock is made adaptive to the real-time signal. So the processor is capable of processing signals from d.c. up to the online aliasing frequency. An example of real-time/online line-voltage fault detection is also included.

DOI:10.1049/ip-e.1980.0006

出版商:IEE    

年代:1980

数据来源: IET

摘要:

A procedure is described which can be used to design digital differentiators satisfying prescribed specifications. The procedure is based on the Fourier-series method for the design of nonrecursive digital filters, and uses the Kaiser window function for the minimisation of the amplitude of Gibbs oscillations. The approach is used to design a number of differentiators assuming various prescribed bandwidths and various prescribed inband errors. It is also used to design a wideband high-precision differentiator. The proposed method is compared briefly with that of McClellan and Parks, based on the theory of weighted Chebyshev approximation.

DOI:10.1049/ip-e.1980.0007

出版商:IEE    

年代:1980

数据来源: IET

摘要:

A technique is described for the optimal synthesis of n-variable combinational logic circuits with Multiplexer universal logic modules, which may readily be implemented without excessive computer storage requirements. The method requires knowledge of the Rademacher-Walsh spectrum, which is an alternative representation of the truthtable vector of the function being considered. It makes use of a property of chosen subsets of these spectra coefficients, which when operated upon can give good indications of the merits of particular decompositions. It is found that an optimal choice of control input variables, and hence aminimal number of multiplexer modules in the realisation, can be made by relatively few tests on the spectral coefficient values.

DOI:10.1049/ip-e.1980.0008

出版商:IEE    

年代:1980

数据来源: IET