With the introduction of cheap programmable l.s.i. components, the designer of digital systems has a great deal of flexibility in implementation, especially in producing multiprocessor systems. To produce cost-effective designs, he needs the ability to design in an implementation-independent manner and then to map this abstract design onto the cheapest hardware-software system consistent with the design objectives. This paper, one of a series, defines some of the primitive constructs which can be used in the design phase and which involve both control and data aspects of the design. An example of the use of these constructs in design is also presented.
Control structures are described to enable the system designer to specify concurrency at the design level by means of programming language or graphical constructs. The structures are designed to obey the rules of structured programming so that the resultant design will be easy to test, modify and understand.
The application of an interactive image-analysis system (Susie) is demonstrated on a variety of tasks in automatic visual inspection, including: (a) the existential inspection and pitch measurement of female screw threads; (b) checking, the legibility of printing on tablets; (c) the enhancement of visibility of industrial radiographs; (d) detecting defects on polished metal surfaces(hydraulics cylinder bores and bright, extruded copper bars); (e) analysing the texture of machined metal surfaces; (f) locating the ends of fibrelike objects (asbestos) viewed under a microscope, as a prelude to counting them or measuring their lengths; and (g) counting, sorting and recognising defects in pressed artefacts, strewn haphazardly onto a table. Susie is ideally suited for evaluating such problems and for prototyping special-purpose visual-inspection systems. It is easy to learn to use Susie and, given suitable optics, an experienced image analyst can very quickly understand the nature of the pictures he is given and develop a suitable strategy for processing them.
The paper describes a method of designing counter registers. Two important features of the method are that it produces a minimal design and that it is guaranteed to avoid jamming. The method may be applied to the synthesis of any counter registers used, for example, as binary-sequence generators, word generators, counters, pseudorandom binary-sequence generators etc. The paper contains examples which demonstrate the design procedure, and gives some results relating to minimal counter registers.
