Accumulator
Accumulator is a very important register for operations in microprocessor. It is used as source of one of the operands to the Arithmetic and Logic Unit (ALU). It is also the destination of the result. The size of the accumulator is the same as the word size of the microprocessor. It is usually represented by a symbol, A.
A microprocessor that uses accumulator for storing data is called accumulator based microprocessor. Usually 8-bit microprocessors are accumulator based. Some of these microprocessors are Intel 8085 and Motorola 6809.
In 16-bit and 32-bit microprocessors the accumulator is replaced by a general purpose register. These microprocessors are called general purpose register based microprocessors. Some of these microprocessors are Intel Pentium and Motorola 68000/68020. When a microprocessor contains many general purpose registers, any one of them can be used as an accumulator.
5 Comments to “Accumulator”
[…] Accumulator Program Counter Status Register Stack Pointer Index Register […]
[…] In this mode, the operand is available in memory but its address is indicated by any one of the register pair. Normally, the address is indicated by the HL (two parts of memory address) pair of memory. The name of the register pair is given as operand. Hence it is indirect. MOV A, M In the above instruction, M refers to HL pair. It moves the content of the memory location indicated by HL pair to accumulator. […]
[…] has three registers: accumulator, temporary register and flag register (SR). Accumulator and temporary register are used to hold the operand of the operations being performed. The result […]
[…] Accumulator: It is a tri-state 8-bit register. Analog – A representation of a physical continuous quantity. An analog voltage or current can have any value within a defined range. […]
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