Specifications

Chapter 1 - Introduction to Microprocessors
Previous page Table of contents Chapter overview Next page
CHAPTER 1
Introduction to Microcontrollers
Introduction
History
Microcontrollers versus microprocessors
1.1 Memory unit
1.2 Central processing unit
1.3 Buses
1.4 Input-output unit
1.5 Serial communication
1.6 Timer unit
1.7 Watchdog
1.8 Analog to digital converter
1.9 Program
Introduction
Circumstances that we find ourselves in today in the field of microcontrollers had their
beginnings in the development of technology of integrated circuits. This development has made
it possible to store hundreds of thousands of transistors into one chip. That was a prerequisite
for production of microprocessors , and the first computers were made by adding external
peripherals such as memory, input-output lines, timers and other. Further increasing of the
volume of the package resulted in creation of integrated circuits. These integrated circuits
contained both processor and peripherals. That is how the first chip containing a microcomputer
, or what would later be known as a microcontroller came about.
History
It was year 1969, and a team of Japanese engineers from the BUSICOM company arrived to
United States with a request that a few integrated circuits for calculators be made using their
projects. The proposition was set to INTEL, and Marcian Hoff was responsible for the project.
Since he was the one who has had experience in working with a computer (PC) PDP8, it occured
to him to suggest a fundamentally different solution instead of the suggested construction. This
solution presumed that the function of the integrated circuit is determined by a program stored
in it. That meant that configuration would be more simple, but that it would require far more
memory than the project that was proposed by Japanese engineers would require. After a
while, though Japanese engineers tried finding an easier solution, Marcian's idea won, and the
first microprocessor was born. In transforming an idea into a ready made product , Frederico
Faggin was a major help to INTEL. He transferred to INTEL, and in only 9 months had
succeeded in making a product from its first conception. INTEL obtained the rights to sell this
integral block in 1971. First, they bought the license from the BUSICOM company who had no
http://www.mikroelektronika.co.yu/english/product/books/PICbook/1_Poglavlje.htm (1 of 9) [4/2/2003 16:17:33]