The processor is the main computing unit of any computer. The processor is a digital circuit made of a silicon chip that performs computation within a fraction of a second. The speed of a processor is measured in terms of megahertz (MHz).
The term processor is often used interchangeably with the term CPU, i.e. central processing unit. Although the CPU is not the only processor in a computer instead, we have GPU, i.e. graphic processing unit, and even the hard drive and the other devices associated with the computer also perform some processing. Still, we refer CPU
In this section, we will discuss different types of processors. So let’s start.
Content: Type of Processors
- What is a Processor?
- Types of Processor
What is a Processor?
A processor is a combined unit holding arithmetic logic unit and a control unit. The main task of a processor is to fetch the instructions from the memory one after the other and perform the required operation. The arithmetic and logic unit performs all mathematical operations, such as addition, subtraction, multiplication, division and other complex operations.
The control unit regulates and integrates the computer’s operation, hence referred to as the computer’s nerve centre. The control unit directs all the activities in the computer, from accepting the user program to processing or executing the program to produce the output and up until the output leaves through the output unit.
In addition to ALU and control unit, the processor even contains the fastest memory elements we refer to as registers. I have explained registers working and type in a separate content Register Organization.
The processor also responds and executes the basic instructions that are compulsory to drive the computer. This is why we always refer processor as the brain of the computer. Knowing this much about the computer lets us discuss the types of processors in the section ahead.
Types of Processors
General Purpose Processor
The General-Purpose Processor (GPP) is programmed by the user. It can handle a wide range of variety of applications. The GPP is designed especially for the general-purpose computer such as desktops and workstations. The primary consideration while designing GPPs is its speed; cost is always a secondary consideration.
The general-purpose processor is of five types:
- Embedded Processors
- Digital Signal Processor
The microprocessor is the processor where the complete processor is fabricated on a single chip. It contains ALU, control unit and registers.
Intel developed the first microprocessor, 4004, in the year 1971. The microprocessor was the first processor containing all the CPU components on a single chip.
The microprocessor 4004 would only add two 4-bit numbers and perform multiplication only by repeated addition. It was not as powerful as today’s microprocessors, but it leveraged the evolution of microprocessors in terms of capability and power.
Over the years, the number of bits a microprocessor can handle has increased. We can measure how many bits a microprocessor can handle with the width of the data bus. The data bus width indicates how many bits can be brought into or sent out of the microprocessor at a time.
The recent microprocessor Intel Core i9 could handle 64 bits at a time. The Microprocessors are low-cost but highly reliable. They are small in size and consume less power. Thus, used in many digital devices, such as cameras, cell phones, kitchen appliances, and car. Nowadays used in toys also.
Microcontroller is actually a computer on a chip. Not only does the processor circuitry, but it also contains some memory, I/O interfaces, timer circuits, and some other features. The microcontroller highly emphasizes integration, low power consumption, self-sufficiency and cost-effectiveness.
The first microcontroller developed by Intel is 8051. The microcontroller 8051 includes a Boolean processing engine which allows bit-level Boolean logic operations. It even has a separate set of registers that can reduce interrupt context in a stack.
Microcontrollers are mostly used in automatically controlled devices such as automobile engine control systems and remote controls in office machines, appliances and toys. Due to its reduced size, cost, and power consumption, it is embedded inside the devices so that they can control the feature and actions of that particular device. This is why we also refer to microcontrollers as embedded controllers.
For example, if your microwave has an LCD screen, it contains a microcontroller and may have six or seven.
Microcontroller usually consumes less power. A battery-operated microcontroller might consume 50 milliwatts. A microcontroller has a dedicated input device and usually has an LCD or LED for displaying output.
The embedded processor is specially designed for embedded systems. Embedded systems are usually small computers designed to control electrical or mechanical functions. The embedded processor does not have to be extremely fast, nor they have to perform heavy computations, and neither they have to possess great input and output capability. Thus, the embedded processor is inexpensive.
Digital Signal Processor (DSP)
The digital signal processor analyzes and processes signals and data from areas such as science and engineering, medicine, economics and humanities. The DSP processor performs numerical manipulation of signals and data in digital form.
Applications of DSP processors are
- Communication: detection, filtering, encoding, and decoding of digital signal
- Image Processing: Filtering, enhancing, coding, compression, pattern recognition.
- Instrumentation: filtering
- Speech Application: noise filtering, coding, compression, recognition, and synthesis of artificial speech.
Application-Specific Instruction Set Processors
Application-Specific Instruction Set Processor (ASIP) is a processor specifically designed for a particular application or domain. The instruction set of the ASIP processor is tailored to accelerate the most used functions of the applications.
Unlike the general-purpose processor designer, who must think of maximum performance and flexibility, the ASIP processor designer must think about the application and cost first. The ASIP processor provides great computational efficiency as compared to general-purpose processors.
The multiprocessor computer has multiple processing units or CPUs with common main memory and all the peripheral devices attached to the computer. These processors simultaneously process the different portions of the same program.
So, in this content, we have discussed different types of processors. Nowadays, most of electrical devices have processors. Everything that can be monitored or programmed to perform specific actions does contain a processor.