Comparison of microprocessors and microcontrollers

Microprocessors and Microcontrollers

Here we will summarize our discussion about the structural point of view on the microcontrollers and microprocessor. In last some post we have detailed discussed the computers, microprocessors and microcontrollers. As we know that the Microcontrollers store their program code to be executed inside the MCU in the form of binary numbers which are actually the voltage levels of +5V and 0V to represent binary levels 1 and 0. The programs and software all uses the data in only two digits 1 or 0. One digit either 1 or 0 is called one bit and 8 such bits tighter are called byte. The program of microcontroller is normally stored in non-volatile ROM which is executed depending upon the information sequencing in set of instruction written in that program. The processor or CPU of microcontroller then operates the input or output devices attached in project and also stored data.

Now we will discuss the data processing capabilities of microcontrollers and microprocessors. The microprocessors while processing the data in execution of software or programs, usually execute these bits together. Some of the microprocessor are powered enough to handle the data 8 bits tighter and some do 16 bits together.  The larger microprocessors can handle the code in 8-bit binary words, or multiples of 8 bits. The two bytes tighter is called one word or data word. The data word size has increased with the passage of time as advancements in this field is continuous which also increase the complexity of the integrated circuits too. The capacity of execution of various microprocessors is discussed in the table below; here are these some examples because actual number of microprocessor is very much more.

The first generation of microprocessor based PCs popular as home computers were like the Commodore, Apple, BBC and Spectrum used 8-bit microprocessors. In these computers the information comprising of program and data words all of these were 8-bit based. Then the second generation of computers came like home games machines such as the Atari and Amiga. The second generation computers used the 16-bit word and mostly use the 68000 chip processor inside these computers. Similar kind of processor was also used in the Apple Mac. It may be noted that it was the first mass-produced computer to use a WIMP interface.

On the other hand the IBM PC which was a business-oriented personal computer. The IBM PC was designed to use the Intel 8088 processor. At that time the 8088 Intel processor could handle 16 bits inside the CPU on motherboard and only 8 bits external interfaces. Similarly the Intel processor also went through many developments and then it can load the 32-bit and or 64 bit together in the very much pronounced Pentium processor series which is continue still. The power of microprocessor not only increased in the way said earlier like execution of information in more bits together but also in the term of clock speed.

 

Now we should come back to our microcontroller perspective. The advancements in microcontroller was also done with the passage of time. Initially the microcontrollers were 8bits processing but later on the microcontrollers were designed to handle the number of more bits at the same time. Historically saying that, the Intel 8051, Intel MCS-51, was one of the first widely used microcontrollers. It was designed to work 8bit processing mode. It is well established in the industrial control market and automation of may machines. Then the PIC family came, it is challenging for the position of leading microcontroller type. It was manufactured by Microchip. It was launched with some additional feature at that time like easily re-programmable feature was very good for beginners.

Now by going through this whole discussion in this post and earlier posts, we hope it is easily convinced that the microcontrollers are very good to use for control application anywhere in general and in industry as well. Rest is that the only question remain arises is that which microcontroller may be used for a specific application to solve a problem. There are many factors which involves in addressing this very important question regarding the selection of the microcontroller for a certain task. In which the factor of costs is really very important. To select the cheapest device is of course logical, but it must match the application’s needs. Now a days it is learnt that the microcontrollers are tailored for specific applications too. However there is a wide variety of microcontrollers available in market to choose from.

various microprocessor characteristics comparison

Now we start it in a sequence, like first of all one should select the controller family means the vener or manufacture which more associated with the controller’s architecture. It may be noted that the microcontrollers a family controller contain the same processor core. These are code-compatible generally. The difference would be in the additional components/ feature like the number of timers or the amount of memory, PWM, USART, IOs etc. The different controller families like 8051, PIC, HC, ARM are as an example of good choice.

Figure  Comparison of AVR 8-bit Microcontrollers specifications AVR, ATmega, ATtiny, Intel MCS-51.

In the above table the data shows a selection of microcontrollers of Atmel’s AVR family. The thing all these microcontrollers have common is their AVR processor core. This family has 32 general purpose registers and executes most instructions within one clock cycle.

The next step is to choose the right microcontroller for the application under consideration within the selected family of microcontroller. Here the choice of microcontroller number wil be based upon the most basic features of the microcontrollers for example memory, digital and analog I/O, and interfaces, Timers, Interrupts, PWMs, USARTs etc. The chosen microcontroller will cover the hardware requirements of the application along with to estimate the application’s speed.