21-09-2017, 11:13 AM
Microprocessor
A microprocessor popularly known as "computer on a chip" in its early days, is a central processing unit commonly used (CPU) manufactured in a single integrated circuit (IC) and is a complete digital computer (microcontroller later considered more precise form of the complete computer). It is a small but very powerful electronic brain that operates at a blistering speed and is often used to carry out the instructions of a computer program to perform arithmetic and logic operations, store data, control the system, input / output etc. according to the instructions. The key term in the definition of a microprocessor is "general purpose". This means that, with the help of a microprocessor, one can build a simple system or a large and complex machine around it with some additional components depending on the application. The main task of a microprocessor is to accept data as input from input devices, then process this data in accordance with the instructions and provide the output of these instructions as output through output devices. The microprocessor is an example of a sequential logic device since it has internal memory and uses it to store instructions.
The first commercial Microprocessor was released by Intel in the year 1971 November named as 4004 (four-thousand-four). It is a 4-bit microprocessor.
There are five important components in a microprocessor. They are arithmetic and logical units (ALU), control unit, registers, instructions decoder and data bus, but the first three are considered significant components. The block diagram of a microprocessor with these basic components is shown below.
The internal structure of a microprocessor is shown below.
Previous microprocessors used the Von Neumann architecture where data and instructions (programs) are stored in the same memory. Although this architecture is simple, there are many backs. One of the main drawbacks is that the instruction and data can not be accessed while sharing a single data bus. This often degrades the overall performance of the device. Subsequently, the Harvard architecture is introduced, which uses separate program and data memories with separate buses, so that data and instructions can be accessed at the same time. Subsequently the Harvard modified architecture was developed, in which the program memory is accessed as if it were a data memory.
There are three basic features used to differentiate microprocessors. They are set of instructions, bandwidth and clock speed. The set of instructions is related to the programming of the microprocessor consisting mainly of instructions that a microprocessor can execute. Bandwidth indicates the maximum number of bits processed in a single instruction. The clock speed does not. of instructions that a processor can execute per second. Normally the clock speed is in MHz (Mega Hertz) or GHz (Giga Hertz). In general, the characteristics of bandwidth and clock speed are looked at together. The higher the values of both features, the more powerful the processor.
The instruction set or instruction set architecture (ISA) also plays an important role in the design and operation of a processor. The microprocessors are classified as CISC (Complex Instruction Set Computer) or RISC (Small Instruction Set Computer).
The CISC architecture consists of a complete set of instructions that are complex, larger, have more computational power, and so on. A single CISC instruction can be used to perform various low-level operations, multi-step operations, and multiple addressing modes. The execution time of these instructions is long. The Intel X86 is an example of CISC architecture.
The RISC architecture was developed by realizing that instead of using a complete set of instructions, only frequently used instructions are sufficient. In this architecture, the instructions are small and highly optimized. RISC processors are used where the execution time of the instruction must be lower and the development cost is lower. ARM devices are based on the ARM architecture which is a subset of RISC.
Microcontroller
The main reason for the development of the microcontroller is to overcome the only drawback of the microprocessor. Although microprocessors are powerful devices, they require external chips such as RAM, ROM, input / output ports, and other components to design a complete work system. This made it economically difficult to develop computerized consumer devices on a large scale since the cost of the system is very high. Microcontrollers are devices that actually fit into the "Computer on a Chip" profile, as it consists of a main processing unit or processor along with some other components that are required to make it a complete computer. The components that are present in a typical IC of a microcontroller are CPU, memory, I / O ports and timers. The first microcontroller was developed in 1971 by Texas Instruments and is called TMS 1000. It was made available for commercial use in 1974. The block diagram of a microcontroller is shown below.
Microcontrollers are basically used in embedded systems. The computerized or digital control of the devices becomes plausible with the development of microcontrollers. The development process of the microcontroller is similar to that of a microprocessor.
Microcontrollers can be classified according to bus width, memory structure and instruction set. The width of the bus indicates the size of the data bus. Microcontrollers can be classified as 8-bit, 16-bit or 32-bit based on the bus width. Higher bus widths often result in better performance. Microcontrollers can be divided into two types based on their memory structures: integrated memory and external memory. In the case of built-in memory microcontrollers, the required data and program memory are embedded in the IC. While the external memory microcontrollers do not have program memory embedded in them and require an external chip for it. Today, all microcontrollers are built-in memory microcontrollers. The classification based on the set of instructions is similar to that of a microprocessor. They can be CISC or RISC. Most microcontrollers follow the CISC architecture with more than 80 instructions. Microcontrollers can also be divided according to their computer architecture in von Neumann and Harvard.
The following table exemplifies some of the differences between microprocessors and microcontrollers.
A microprocessor popularly known as "computer on a chip" in its early days, is a central processing unit commonly used (CPU) manufactured in a single integrated circuit (IC) and is a complete digital computer (microcontroller later considered more precise form of the complete computer). It is a small but very powerful electronic brain that operates at a blistering speed and is often used to carry out the instructions of a computer program to perform arithmetic and logic operations, store data, control the system, input / output etc. according to the instructions. The key term in the definition of a microprocessor is "general purpose". This means that, with the help of a microprocessor, one can build a simple system or a large and complex machine around it with some additional components depending on the application. The main task of a microprocessor is to accept data as input from input devices, then process this data in accordance with the instructions and provide the output of these instructions as output through output devices. The microprocessor is an example of a sequential logic device since it has internal memory and uses it to store instructions.
The first commercial Microprocessor was released by Intel in the year 1971 November named as 4004 (four-thousand-four). It is a 4-bit microprocessor.
There are five important components in a microprocessor. They are arithmetic and logical units (ALU), control unit, registers, instructions decoder and data bus, but the first three are considered significant components. The block diagram of a microprocessor with these basic components is shown below.
The internal structure of a microprocessor is shown below.
Previous microprocessors used the Von Neumann architecture where data and instructions (programs) are stored in the same memory. Although this architecture is simple, there are many backs. One of the main drawbacks is that the instruction and data can not be accessed while sharing a single data bus. This often degrades the overall performance of the device. Subsequently, the Harvard architecture is introduced, which uses separate program and data memories with separate buses, so that data and instructions can be accessed at the same time. Subsequently the Harvard modified architecture was developed, in which the program memory is accessed as if it were a data memory.
There are three basic features used to differentiate microprocessors. They are set of instructions, bandwidth and clock speed. The set of instructions is related to the programming of the microprocessor consisting mainly of instructions that a microprocessor can execute. Bandwidth indicates the maximum number of bits processed in a single instruction. The clock speed does not. of instructions that a processor can execute per second. Normally the clock speed is in MHz (Mega Hertz) or GHz (Giga Hertz). In general, the characteristics of bandwidth and clock speed are looked at together. The higher the values of both features, the more powerful the processor.
The instruction set or instruction set architecture (ISA) also plays an important role in the design and operation of a processor. The microprocessors are classified as CISC (Complex Instruction Set Computer) or RISC (Small Instruction Set Computer).
The CISC architecture consists of a complete set of instructions that are complex, larger, have more computational power, and so on. A single CISC instruction can be used to perform various low-level operations, multi-step operations, and multiple addressing modes. The execution time of these instructions is long. The Intel X86 is an example of CISC architecture.
The RISC architecture was developed by realizing that instead of using a complete set of instructions, only frequently used instructions are sufficient. In this architecture, the instructions are small and highly optimized. RISC processors are used where the execution time of the instruction must be lower and the development cost is lower. ARM devices are based on the ARM architecture which is a subset of RISC.
Microcontroller
The main reason for the development of the microcontroller is to overcome the only drawback of the microprocessor. Although microprocessors are powerful devices, they require external chips such as RAM, ROM, input / output ports, and other components to design a complete work system. This made it economically difficult to develop computerized consumer devices on a large scale since the cost of the system is very high. Microcontrollers are devices that actually fit into the "Computer on a Chip" profile, as it consists of a main processing unit or processor along with some other components that are required to make it a complete computer. The components that are present in a typical IC of a microcontroller are CPU, memory, I / O ports and timers. The first microcontroller was developed in 1971 by Texas Instruments and is called TMS 1000. It was made available for commercial use in 1974. The block diagram of a microcontroller is shown below.
Microcontrollers are basically used in embedded systems. The computerized or digital control of the devices becomes plausible with the development of microcontrollers. The development process of the microcontroller is similar to that of a microprocessor.
Microcontrollers can be classified according to bus width, memory structure and instruction set. The width of the bus indicates the size of the data bus. Microcontrollers can be classified as 8-bit, 16-bit or 32-bit based on the bus width. Higher bus widths often result in better performance. Microcontrollers can be divided into two types based on their memory structures: integrated memory and external memory. In the case of built-in memory microcontrollers, the required data and program memory are embedded in the IC. While the external memory microcontrollers do not have program memory embedded in them and require an external chip for it. Today, all microcontrollers are built-in memory microcontrollers. The classification based on the set of instructions is similar to that of a microprocessor. They can be CISC or RISC. Most microcontrollers follow the CISC architecture with more than 80 instructions. Microcontrollers can also be divided according to their computer architecture in von Neumann and Harvard.
The following table exemplifies some of the differences between microprocessors and microcontrollers.