Introduction
Since the invention of the first microprocessor from intel-4004 microprocessor, many changes have occurred in the field of electronics and microprocessors. Microprocessors have continued to decrease in their size and increase in their speed at a very alarming rate, consequently revolutionalizing the way individuals live as well as operate on a day-to-day basis (Kowalewski.S 2010). We are used to the microprocessors that are found in the PCs and most times we neglect the other much smaller powerful and very efficient gadget in this family; the microcontroller. As opposed to the microprocessor which is common in our laptops as well as PCs microcontrollers command a wide usage in most automated devices or electrical. Without the microcontrollers, it would be quite impossible for cell phones, which are in great use today to exist, let alone be used (F 2010).
The micro-controller is an essential component that is concerned with the interpretation and processing of data. As a result, it accepts input and processes it to give a particular output. Microcontrollers embedded into appliances, automate actions or operations. This flexibility and portability are attributed to the small size of the component as well as its light nature. It also consumes relatively low power in its performance, further making it a device of choice for most electrical gadgets (Kowalewski.S 2010).
The device contains three major parts, which include a processor core, programmable input as well as output peripherals. The processor aids in facilitating the interpretation of data as well as its subsequent processing to yield the expected result. This feature is quite crucial in system development, as it will facilitate the interpretation of data.
The programmable ability of the microcontroller is very handy to any system since it is upon this that action automation becomes a reality using a given programming language. The programs control the operations of other devices within the system, it is through the programs that algorithms of operations are set in an effort to determine as well as control how data interpretation and processing takes place. The microcontroller is therefore a very crucial device that largely determines the fulfillment of the objective of the system, provided the right algorithms are set in the programming stage (F 2010). The microcontroller chip also has a memory within it that facilitates the storage of set algorithms as well as programs that guide its operations for the fulfillment of a given objective. The size of the memory differs depending on whether a system is to perform a single task or multiple tasks, for multiple tasks a large memory space is required.
One distinguishing feature of the microcontroller is its ability to handle interruptions much the same as a microprocessor in personal computers. Such interrupts are important to a system in the context of limiting power consumption. An interrupt triggers the microcontroller from a low-power sleep to an active state. Therefore, when the system is not in use, its processor halts (low power sleep), and only an interrupt requiring the system to perform a given task can trigger it into action, therefore saving on power consumption by the microcontroller (Kowalewski.S 2010).
Intel was also privileged to be the inventor of the first microcontroller; Intel 8048. From this point, many firms came up with diverse microcontrollers that differed in features as well as characteristics, each aimed at making much faster microcontrollers that were equally efficient. Despite the diversity in the manufacture and production of the device, Intel’s architecture remained the de facto system from which all other microcontrollers including the modern ones derive their architecture.
This paper attempts to compare the features of the different types of microcontrollers in the PIC microcontroller family. More emphasis is given on the technical aspects of the microcontrollers though their market trends will also be mentioned (Kowalewski.S 2010). To enhance understanding in this field illustrations such as tables are used in the comparisons of the different features of the microcontrollers highlighted. An objective conclusion on the topic of discussion was drawn in a bid to give a critical perspective on the topic put forth.
Programming language
Visual basic, which is a high-level programming language, commonly used to prepare graphical user interfaces coded to perform given function and return certain results. It is easy to use for purposes of programming as it employs a drag and drop technique to create controls such as buttons and text boxes on windows or forms. These controls have attributes as well as event handlers that are related to them, they are the thus the building blocks of the programs designed in visual basic.
The techniques applied in this programming language facilitate the creation of programs with a graphical interface without much hassle. This ensures convenience on both the programmers’ side and the users’ side since the programmer finds it easier to program at the same time the user finds the resulting application quite user friendly. Most controls used in visual basic have default codes hence it saves on a lot of time that could have been used to generate new codes, and all one has to do is to add a few codes for purposes of customization in relation to a given system (Kowalewski.S 2010).
Major components for controllers include
When selecting a microcontroller there are characteristics that are always common regardless of the make or the manufacturers of the microcontroller, it is important to look at the these components and their importance they are the major functions in a micro controller, they do determine the efficiency of a micro controller, though there are other features and that these features do vary in regard to various manufactures that make them. These are the major components in a microcontroller (Kowalewski.S 2010).
- CPU / Processor
- Memory (RAM, ROM or EEPROM,)
- Control pins: the reset, power, and clock.
- Serial and Parallel ports
- Timers
- Analog-to-digital (A/D) and digital-to- Analog (D/A) converters
- Input / Output ports
It is important to discuss the functions of the following components which make it easier to campare two microprocessors and be able to come up with differences between microcontrollers.
Components and their function
CPU / processor
The CPU processes instruction and data, the parts of a processor include registers (which are fast memory used to store operand and other information
Memory (RAM, ROM or EEPROM,)
There are various technologies used to store data memories they include Random Access Memory (RAM) which is used to store volatile data when the processor is running, to be more specific it holds data program instructions and also data during the execution process, this kind memory can be retrieved at a any random order which is not the case with other kinds of storage medium like the disks and tapes (Kowalewski.S 2010).
There are varicose types of RAM; they include the static RAM (SRAM) which operates on transistors to be able to keep bits, fast static RAM is used as cache memory (memory which stores frequently used data.
There is the Dynamic Random access memory (DRAM) which used capacitors to store its bits, it must be refreshed constantly, it smaller than the static RAM and also cheaper. The Dynamic RAM has a family that includes; synchronous DRAM (SDRAM)- which was introduced in the year 1997 which took the place of most of the DRAM in computers by the year 2000, there is also the double data rate DDR SDRAM which uses both clock edges found that are mostly resident in most of today’s computers, there is also the Direct Rambus DRAM (RDRAM).
The ROM
The Read only memory is only read from, it carries out functions like holding program instruction, they are used in embedded systems whereby the code is does not change and execution always is the same when the system is switched on, they are also use to store booting information in the computer. The ROM has other types of memory which include
Erasable programmable ROM- which is just like the ROM but its data can be erased by exposing light (ultraviolet light) and then reprogrammed,
There is the Electrically Erasable programmable ROM (EEPROM)- it is more commonly used for the reason that it can be altered by the microprocessor.
The input output ports
The input output (I/O) ports connect to the world outside, example of these connection are like the analog to digital conversion, display and communication circuit..Analog-to-digital (A/D) and digital-to- Analog (D/A) converters allow outside allow collection of information form the outside a system e.g. temperature and pressure which can them be interpreted in to a digital form. The Serial and parallel ports are input output ports only that in a microcontroller they are still embedded in chip unlike the microprocessor
Timers
They provide time frames by which operation are carried out providing a sequence of events.
Control pins
They are line that carry particular instructions.
The characteristics for the PIC24F microcontroller1
The characteristics for the freescale S12 microcontroller
The comparison for the PIC24F and the freescale S12 microcontroller and the reason for their table in order
The architecture is the foundation by which the microprocessor is built it dictates the overall capacity of the microcontroller the CPU speed is based in the on the base bit that the architecture carries hence the architecture is overall important compared to any other characteristic(F 2010).
The CPU speed determines the over al speed of the microcontroller reducing the time between command and execution cycle hence the internal oscillator is basically founded in this.
Pin count denotes the number of address lines that a chip has the more the pins the faster the response form a microcontroller, pin count is more important than I/O pins depends on other pins to make them more efficient. Serial and parallel ports are also dependent on the pins that are available.
Timer are crucial during the execution processes, the timers kind of coordinate what is to take place after what activity, for instance during data conversion from analog to digital the timers do dictate when the read operation will take place and when the write operation will take place, so the analog to digital converters are very reliant on the timers.
Memory type is very important as far as read write operations are concerned also the issue of cost comes in the size of the program memory is also very dependent on the type of memory used (F 2010).
Serial and parallel ports do determine the kind of peripheral to be used, to input.
Operating voltage does determine the kind of machine to use with small machines that are use less power require low cost power consumption in most cases the voltage used also determines the range of temperature.
References
Kowalewski, Stephan. Formal methods for industrial critical systems. New york: springer, 2010.
Steven, Farret. Arduino Microcontroller. London: Morgan & Claypool, 2010.