Microcontrollers are mostly programmed using assembly language but in recent years high level languages like C, C++ PASCAL and java have been used. 5 High level programming of microcontrollers brings the advantage of not having a different program for each microcontroller manufacturer. High level programming is also neat, easy to document and maintain and user friendly.
Types of Microcontrollers
These are among the earlier microcontrollers to be fabricated. Due to superiority in technology in the newer versions, very few companies still fabricate 8051. Earlier types of 8051 have 12 clocks per instruction whereas the newer versions have 6 clocks per instruction. 8051 microcontroller does not have an in built memory bus and ADC. First 8051 microcontroller to be fabricated with Harvard architecture was done in 1980 by Intel. 1
Programmable Interface Controller (PIC)
Programmable Interface Controllers are commonly referred to as PIC. PICs are slightly older than 8051 microcontrollers. PICs are preferred to 8051 because of their small low pin count devices. PICs perform better and are affordable than 8051. 3 The Microchip technology fabricated the single chip microcontroller PIC with Harvard architecture. The only major downside of PIC is its programming part is very tedious. PICs are hence not recommended for beginners.
In 1996, Atmel fabricated this single chip microcontroller with a modified Harvard Architecture. This chip is loaded with C- compiler and a free IDE. Like PIC, AVR microcontrollers are difficult for the beginners to work with. AVR microcontroller has on-chip boot-loader thus AVR can be programmed easily without any external programmer. 3 AVR controllers has number of I/O