Microprocessors

4 Types of Processor Architectures

Processor architecture can be classified as one of the following four architectures:

  • Accumulator-based processor architecture
  • Register-based processor architecture
  • Stack-based processor architecture
  • Pipeline processor architecture

Accumulator-Based Processor Architecture

Figure 1.1 Accumulator-based processor architecture

In the accumulator-based processor architecture, illustrated above, instructions begin and end in accumulators (Acc A and Acc B), which are specially designated registers. In a typical operation, one of the operands is found in the accumulator and the other is to be fetched from memory. The result of the operation is placed in the accumulator. Since one of the operands needs to be continually fetched from memory, this architecture is slower than the register-based and stack-based architectures. Nonetheless, accumulator-based architecture has the ability to run fairly complicated instructions.

Register-Based Processor Architecture

Figure 1.2 Register-based processor architecture

In register-based processor architecture, both operands are stored in registers and the result of operation is also stored in a register. The registers are typically collocated with the processor. Since the processor and registers operate at the same speed, this architecture is much faster than the accumulator-based architecture. The contents of the register are read from and written to memory using background operation.

Stack-Based Processor Architecture

Figure 1.3 Stack-based processor architecture

In a stack-based architecture, both operands and the operation to be performed are stored on the stack, which could be configured around dedicated registers or a special portion of RAM. The result of operation is placed back on the stack.

Pipeline Processor Architecture

Figure 1.4 Pipelined architecture

In the pipelined architecture, as demonstrated in Figure 1.4 above, there is separate hardware stages of execution of different steps involved in the execution of an instruction. These different steps include fetching an instruction from memory, decoding the instruction, fetching instructions operands from memory or registers, executing the instruction and then finally placing the result back on the memory. Pipelining allows these stages to overlap and perform with parallelism. The overall result is that the execution of an instruction is completed on every clock cycle. Instructions in a pipelined architecture are typically simple instructions that can be implemented within a single stage. These simple instructions act as building blocks for more complex instructions.

John Mulindi

John Mulindi has a background in a technical field and he writes on topics ranging from automation, computer systems, embedded systems, mechatronics to measurement and control.

View Comments

Recent Posts

Rigid-Flex PCBs: Enhancing Durability and Flexibility in Electronic Devices

The world of electronics is constantly evolving, allowing designers and manufacturers to push the boundaries…

3 months ago

Key Features of PIC16X84 Family of Microcontrollers

PIC microcontrollers are fabricated by Microchip Technology. PIC16C84 and PIC16F84 are the two microcontrollers in…

10 months ago

ADD Instruction in Intel 8051 (MCS-51) Microcontroller

The ADD instruction tells the microcontroller’s CPU to add the source byte to register A…

10 months ago

Main Features of Intel 8086 Microprocessor

8-bit microprocessors are limited in their speed (the number of instructions that can be executed…

10 months ago

Basic Features of 68HC11 Family of Microcontrollers

The 68HC11 (also abbreviated as 6811 or HC11) is an 8-bit microcontroller that was introduced…

10 months ago

Process Synchronization using Semaphores

Mutual exclusion typically imposes some conditions on access to a given resource by two or…

11 months ago