Registers
A special, high-speed storage area within the CPU. All datamust be represented in a register before it can be processed. For example, if two numbers are to be multiplied, both numbers must be in registers, and the result is also placed in a register. (The register can contain the address of a memory location where data is stored rather than the actual data itself.)
The number of registers that a CPU has and the size of each (number of bits) help determine the power and speed of a CPU. For example a 32-bit CPU is one in which each register is 32 bits wide. Therefore, each CPU instructioncan manipulate 32 bits of data.
Usually, the movement of data in and out of registers is completely transparent to users, and even toprogrammers. Only assembly language programs can manipulate registers. In high-level languages, thecompiler is responsible for translating high-level operations into low-level operations that accessregisters
Memories
In computing, memory refers to the computer hardware devices used to store information for immediate use in a computer; it is synonymous with the term "primary storage". Computer memory operates at a high speed, for example random-access memory(RAM), as a distinction from storage that provides slow-to-access program and data storage but offers higher capacities. If needed, contents of the computer memory can be transferred to secondary storage, through a memory management technique called "virtual memory". An archaic synonym for memory is store.[1]
The term "memory", meaning "primary storage" or "main memory", is often associated with addressable semiconductor memory, i.e.integrated circuits consisting of silicon-based transistors, used for example as primary storage but also other purposes in computers and other digital electronic devices. There are two main types of semiconductor memory, volatile and non-volatile. Examples of non-volatile memory are flash memory (used as secondary memory) and ROM, PROM, EPROM and EEPROM memory (used for storingfirmware such as BIOS). Examples of volatile memory are primary storage, which is typically dynamic random-access memory(DRAM), and fast CPU cache memory, which is typically static random-access memory (SRAM) that is fast but energy-consuming, offering lower memory areal density than DRAM.
Most semiconductor memory is organized into memory cells or bistable flip-flops, each storing one bit (0 or 1). Flash memoryorganization includes both one bit per memory cell and multiple bits per cell (called MLC, Multiple Level Cell). The memory cells are grouped into words of fixed word length, for example 1, 2, 4, 8, 16, 32, 64 or 128 bit. Each word can be accessed by a binary address of N bit, making it possible to store 2 raised by N words in the memory. This implies that processor registers normally are not considered as memory, since they only store one word and do not include an addressing mechanism.
memories
