Microprocessor 1

2The Function of Memory

Storage is one of the computer’s most important functions. It is omnipresent. It is found in the main memory and obviously in the cache hierarchy, but also in the processor, Input–Output (I/O) interfaces and peripherals. The main memory is made up of integrated electronic components designed for memorization, which are usually soldered onto one or both sides of a small multilayer Printed Circuit Board (PCB for Printed Circuit Board), the whole called a memory module. Memory can also be a functional subset of a more complex chip such as a microprocessor or a microcontroller. It can be present in the form of registers or memory areas of larger size such as a cache or a small main memory chip. In this case, it is referred to as “embedded memory” (cf. V2, a continuation of Darche (2012), forthcoming). It is also found in I/O controllers in these two formats (i.e. register or cache) or in the form of a buffer that manages the flow of information according to the “First In, First Out” (FIFO) policy. A peripheral such as a printer or a Hard Disk Drive (HDD) can also have FIFO or cache-type buffer memory. Solid-state memory, initially in discrete form and then in integrated form beginning in the 1970s, has never stopped increasing in capacity. Manufacturing technologies have evolved over the past 40 years, but the principles of memorization and its internal structure have hardly changed, paradoxically. These technologies form the basis of one of the largest ...