accumulator register
The student examines the accumulator register in the computer architecture diagram.
- Noun:
- (Computer Science) A special storage register within a central processing unit (CPU): An accumulator register is a type of register that contains a built-in adder (or arithmetic logic unit). Its primary function is to hold an intermediate arithmetic or logic result. It "accumulates" a total by having an input number added to (or otherwise combined with) the value currently stored in the register.
- Noun:
- The processor's accumulator register holds the sum after each addition operation.
- In early computer architectures, most arithmetic operations involved the accumulator register.
- The value in the accumulator register is incremented by the input from the data bus.
Historical Context: In many early and simple CPU designs, the accumulator register was the primary, and sometimes the only, register for performing calculations. This architectural style is known as an accumulator machine.
- In the 6502 microprocessor, the accumulator register was central to its operation.
Modern Context: While modern CPUs have multiple general-purpose registers reducing the singular role of a dedicated accumulator, the term is still used in low-level programming and digital circuit design to describe a register that accumulates a sum or result.
- The digital signal processor uses an accumulator register for summing the products in a filter calculation.
Accumulator (n): Often used as a shortened, informal term for "accumulator register."
- The result is stored in the accumulator.
Register (n): A small, high-speed storage location within the CPU.
- Adder (n): A digital circuit that performs addition of numbers.
- Accumulator (when context clearly refers to a CPU register).
- A-register (a common abbreviation in assembly language and computer architecture).
"To load the accumulator": A common instruction meaning to place a value from memory into the accumulator register.
- The program must load the accumulator with the first data value.
"To store from the accumulator": An instruction to save the value from the accumulator register back to memory.
- The final result is stored from the accumulator to the output location.
The student examines the accumulator register in the computer architecture diagram.
- (computer science) a register that has a built-in adder that adds an input number to the contents of the register