In
computer engineering
Computer engineering (CE, CoE, or CpE) is a branch of engineering specialized in developing computer hardware and software.
It integrates several fields of electrical engineering, electronics engineering and computer science.
Computer engi ...
, a register–memory architecture is an
instruction set architecture
In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, ...
that allows operations to be performed on (or from)
memory
Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembe ...
, as well as
registers.
If the architecture allows all operands to be in memory or in registers, or in combinations, it is called a "register plus memory" architecture.
In a register–memory approach one of the operands for operations such as the ADD operation may be in memory, while the other is in a register. This differs from a
load–store architecture
In computer engineering, a load–store architecture (or a register–register architecture) is an instruction set architecture that divides instructions into two categories: memory access ( load and store between memory and registers) and ALU op ...
(used by
RISC
In electronics and computer science, a reduced instruction set computer (RISC) is a computer architecture designed to simplify the individual instructions given to the computer to accomplish tasks. Compared to the instructions given to a comp ...
designs such as
MIPS) in which both operands for an ADD operation must be in registers before the ADD.
An example of register-memory architecture is
Intel x86
x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel, based on the 8086 microprocessor and its 8-bit-external-bus variant, the 8088. The ...
.
Examples of register plus memory architecture are:
*
IBM System/360
The IBM System/360 (S/360) is a family of mainframe computer systems announced by IBM on April 7, 1964, and delivered between 1965 and 1978. System/360 was the first family of computers designed to cover both commercial and scientific applicati ...
and its successors, which support memory-to-memory fixed-point decimal arithmetic operations, but not binary integer or
floating-point arithmetic
In computing, floating-point arithmetic (FP) is arithmetic on subsets of real numbers formed by a ''significand'' (a Sign (mathematics), signed sequence of a fixed number of digits in some Radix, base) multiplied by an integer power of that ba ...
operations;
*
PDP-11
The PDP–11 is a series of 16-bit minicomputers originally sold by Digital Equipment Corporation (DEC) from 1970 into the late 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of a ...
, which supports memory or register source and destination operands for most two-operand integer operations;
*
VAX
VAX (an acronym for virtual address extension) is a series of computers featuring a 32-bit instruction set architecture (ISA) and virtual memory that was developed and sold by Digital Equipment Corporation (DEC) in the late 20th century. The V ...
, which supports memory or register source and destination operands for binary integer and floating-point arithmetic;
*
Motorola 68000 series
The Motorola 68000 series (also known as 680x0, m68000, m68k, or 68k) is a family of 32-bit computing, 32-bit complex instruction set computer (CISC) microprocessors. During the 1980s and early 1990s, they were popular in personal computers and ...
, which supports integer arithmetic with a memory source or destination, but not with a memory source and destination. However, the 68000 can move data memory-to-memory with nearly all addressing modes.
See also
*
Load–store architecture
In computer engineering, a load–store architecture (or a register–register architecture) is an instruction set architecture that divides instructions into two categories: memory access ( load and store between memory and registers) and ALU op ...
*
Addressing mode
Addressing modes are an aspect of the instruction set architecture in most central processing unit (CPU) designs. The various addressing modes that are defined in a given instruction set architecture define how the machine language instructions ...
References
{{DEFAULTSORT:Register-memory architecture
Computer architecture