Semiconductor Memories

Abstract

Many electronic circuits require memory elements to record the state of operation of the circuit at particular instants of time. The most basic form of memory element, known as the set-reset flip-flop (or the S-R flip-flop), consists of two cross-connected NOR gates (for details see section 8.2). This circuit is widely used not only as a memory element in its own right, but also as the basis of more sophisticated elements known as master-slave flip-flops (see section 8.3). The S-R flip-flop is one of a family of memories known as static memories which retain the stored information indefinitely so long as the power supply is maintained; both bipolar and MOS technologies are used in the manufacture of static memories.