Lecture-5
Characteristics of Memory:
In the broad sense, a microcomputer memory system can be logically
divided into three groups:
1) Processor memory
2) Primary or main memory
3) Secondary memory
• Processor memory refers to a set of internal registers. These registers hold
temporary results when computation is in progress.
• Primary memory or the main memory is the internal memory to store both
program and data. The processor can access these memories directly.
• Secondary memory refers to the storage medium compositing slow devices
such as hard disks and floppies. Sometimes, secondary memories are also
referred to as auxiliary or back up storage.
In order to design an efficient memory system, the following characteristics of
memory must be known:
1. Volatile or Non-volatile : An important characteristic of a memory is whether
it is volatile or non volatile. The contents of volatile memory are lost if the
power is turned off. On the other hand, a non volatile memory retains its
contents after the power is switched off. The best known non volatile memory
is magnetic core.
