2 – Technology Progress in Logic and Memories

Publisher Summary This chapter explains the way in which technology progress, particularly in the areas of semiconductor logic, semi-conductor memories, and magnetic memory media, have influenced progress in the computer industry and have provided choice and challenge for computer design engineers. A single transistor circuit, performing a primitive logic function within an integrated circuit, is among the smallest and most complex of man-made objects. Alone, such a circuit is intrinsically trivial; however, the fabrication process required for a set of structures to form a complete integrated circuit is complex. Without well-defined functions such as addition and multiplication semiconductor suppliers cannot provide high density products in high volume because there are few large-scale, general purpose universal functions. The alternative for users is to interconnect simple logic circuits gates; however, that does not permit efficient use of the technology, and the cost per function remains high because the printed circuit board and integrated circuit packaging costs limit the cost reduction. The function performed by a chip is dependent on the number of gates that can be placed on a chip. Thus, density in gates per chip is the single most important parameter determining chip functionality.