Programmable comparator, 1984 and graphic controller using such a comparator

摘要

Digital programmable comparator intended to carry out the comparison between an item of digital input data and a reference digital data item. This comparison is supplied by successive bit slicing of the input data. These programmable slices have sizes of 2k bits. A control generator 34 comprises AND logic operators and selectors. It may be produced in the form of a network having programmed logic and transfer gates. The result of the comparison is supplied according to a digital mask which is used in a graphics controller to validate, or otherwise, according to the logic states of the mask, each bit of the digital input data. Application: digital programmable comparator, graphics controller. IMAGE