Method and arrangement to raise the number of information words to be transferred via an interface between two units of a data processing system

摘要

The number of information words, e.g. command words, to be transferred via an interface between a first unit, e.g. a command memory (BSP), and a second unit, e.g. a control unit (CW), is raised by converting frequently occurring information words into words of smaller bit width, and then recombining these coded words into a code word with the width of the information words. To distinguish between the coded and uncoded information words, a marker bit is added to the information word. After the transfer, the marker bit is inspected, to determine whether the transferred word consists of several coded information words or only of one uncoded information word. If the transferred word consists of several coded information words, it is separated into the individual coded information words using a multiplexer circuit (DMUX), and the coded information words are used as addresses to read the assigned information word from a decoder circuit (DK). The decoded information word is then processed. By combining coded frequently occurring information words into one word of the width of the information words, several information words can be transferred from one unit to another, by transferring one word via an interface. <IMAGE>