Bit-Slice Microprocessors

During the last five years of their existence, microprocessors proved to be the most versatile electronic product which can be used in any conceivable application requiring manipulation of data and flexibility in control. The factors that contributed towards their popularity are simplicity, small size, and low cost. Bit-slice microprocessors significantly helped to widen the range of microprocessor applications. Currently available bit-slice microprocessors are 2-or 4-bit wide and number of bit-slices can be stacked together to realize more powerful CPUs with higher wordlengths. Because of this multi-chip configuration, the overall power dissipation is higher and bipolar technology could be used for fabrication of bit-slice microprces sors as against MOS technology, resulting in higher speeds of about 40 ns clock rates. Bit-slice microprocessors are microprogrammable, thus providing flexibility in CPU design to suit to a specific application. A brief insight into operation of bit-slice microprocessors is provided in this paper, bringing out the features involved in CPU design and microprogramming of currently available bit-slice microprocessors.