Saturday, May 5, 2012
What Is A Microcontroller
Each of these systems will use a microcontroller as their main control unit:
- Car lock remote key fob.
- TV Remote control.
- Security system.
- Electronic safe.
- Car anti lock braking system.
- Satelite decoder.
- DVD player.
- Toaster.
A microcontroller is an all in one electronic integrated circuit with built in processor memory and peripherals that is also re-programmable.
You may not be able to recognize the microcontroller as for cost savings its cheaper to build an ASIC (Application Specific Integrated Circuit). This is a custom chip designed only for the product which is mass produced in milliions making the cost of the device far cheaper than using an individual microcontroller.
Nevertheless each system is based on a microcontroller.
Electronic Circuit design has progressed from individual transistors which are based on silicon to placing thousands and then millions of transistors on a single silicon wafer. The transistors, arranged in the correct configuration, perform different functions such as time delays, boolean logic, memory etc.
7400 series logic
Still available today are the older 74 series devices. These are ICs encased in plastic with connection pins on the outside and each one performs a different well defined function.
By grouping these devices together you can make up circuits by connecting the pins of the device to pins of other devices. About 20 years ago this was the only way of making digital electronic systems and you would typically have racks of circuit boards each with 50 of these devices wired up.
More transistors
Of course the disadvantage of these racks of circuit boards is that once you have designed the board you can not change it so you had to be absolutely sure that the design was perfect. If it was not then you had to start over - and for a complex system that means spending money on a new circuit board and spending time re-designing it.
With the advance of manufacturing techniques more transistors can be put on the silicon wafer - and if you can get more transistors on a wafer there are two advantages.
- Increased functionalty.
- Higher speed.
Smaller transistors means smaller physical problems (capacitance slows down a devcie - so a smaller device has less) and they also use less current. Less current means less power and less power means less heat and less heat means that the device can operate faster.
Given enough transistors you can design a circuit (or Integrated Circuit - ICs) to perform virtually any function you can think and using a special form of transistor (flash memory) means that the device can store information for years - this memory is also re-programmable.
Processor
The next stage in development was creating the processor which is a specialised circuit in which the function of the device is not set at all. Instead the device is capable of performing different functions when it is given different inputs and not only that - it has a small amount of ram inside used for internal temporary storage (registers) - and this lets it remember a sequence of events.
When you combine this device with two types external memory (other ICs) you can make a system that can follow a defined sequence of events. By reading instructions from the memory (ROM) the processor knows what it should be doing as its next event sequence and it can store data in external RAM memory.
- ROM - Read Only Memory (permament)
- RAM - Random access memory (temporary - when power goes info is lost).
In addition the processor can read the state of input pins and set the state of output pins so it can react to the outside world e.g. turn on a light or read a key press.
You can see where this is going - it's a device that has re-programmable memory and has many of the building blocks (7400 series) although now greatly refined and adapted inside the device - it's the microcontroller.
Microcontrollers
A microcontroller is a specialized integrated circuit which combines a processor and external memory inside the silicon wafer itself. You now have a customizable device that you can change its function just by re-programming it.
In addition as microcontrollers have been refiined you will find devices that have many other peripherals inside them. Where once you had to buy a UART IC (an RS232 communication device - to talk to a PC) and place it on the processor bus in addition to the RAM and the ROM; this device is now part of the microcontroller itself.
Here are the internal peripherals of the 16F88 a modern PIC microcontroller - this is just an example there are many more microcontroller manufacturers e.g. Atmel, Motorola, Zilog.
- RAM 386 Bytes.
- ROM 4096 words.
- EEPROM 256 Bytes.
- I/O 16 pins.
- Internal oscillator.
- Timer 1.
- Timer 2.
- Timer 3.
- USART. SSP - Synchronous Serial port I2C, SPI protocols.
- CCP - Capture Compare PWM.
- Analogue comparator 1.
- Analogue comparator 2.
- ADC multiplexed inputs from 7 pins.
This an 18 pin IC which is as big as some of the original 7400 devices but it can do much more that those single chips. For instance you can make the following types of projects using it:
- Universal Infrared decoder/encoder.
- Ultrasonic tape measure.
- Frequency counter.
- Metal detector.
Note: All of these projects can be made using the same device because you can re-program the microcontroller to do a different job.
You can find more information here: microcontroller information and how to build a website that gets the click.
Copyright © John Main 2006
Free to distribute if the article is kept complete.
Guide to Learning The Microcontroller Embedded System
Are you a young school student looking for study data to learn microcontrollers?
Are you a high school / college student looking for information to design your microcontroller based project?
Are you an old man planning to convert your old digital technology based design to a compact microcontroller based design?
Are you working in an organization and want to upgrade your skills for microcontroller and embedded system design?
You all are from variety of age, expertise and skill levels. But your need is same. Your basic question is same. Your objective is same. That's to "Learn Microcontroller based design."
You are on right track as you have decided to go along with microcontrollers for your all electronics projects. There is no other good method than using a microcontroller in product design.
Here are the steps and information for you to get started:
1. Your knowledge and ability:
Every human is unique in the knowledge he has acquired and the abilities he has.
Knowledge indicates the "experience" and ability indicate "time required to solve a design problem"
e.g. I know C language very well but I can't solve a "Array Sorting program easily."
This indicates having knowledge of C programming is not enough but one should have good ability to "Analyze and solve the problem statement".
And this is the key and most important feature required while working with any microcontroller based embedded design system.
In other word this ability to solve problems is called as "Logic of creating solutions".
2. Hardware & Software
Microcontroller based embedded system designing is combination of hardware and software.
Microcontroller is a small Integrated Chip (IC) and is the hardware part of the system. This small chip called microcontroller has facility to store a "Program" inside it. This is called as software.
You as a product designer, must have both expertise. Lets understand this by one example:
"You have been assigned a simple task to design and develop a product to display room temperature"
This project will need following components:
1. The temperature sensor (e.g. LM35)
2. A Microcontroller (e.g. ATmega8 AVR) to read the data from temperature sensor.
3. A 16 chars by 2 lines (16x2) LCD display
4. DC Voltage regulator 5V (7805 based)
Once you have this set ready, then its time to create a circuit / schematics for this.
Here is the point where you start learning about internals of microcontroller ATmega8.
Learn the hardware aspect of this microcontroller and then the software. The software writing is using Assembly or C Language.
3. Tools and equipments
A PC / Laptop, installed with IDE (development environment), ISP Programmer hardware, Starter kit / target board and some books or reference manuals or a Computer based Tutorial.
In above example we have selected ATmega8 microcontroller. This is made by ATMEL and is from AVR family of controllers. This is 8 bit controller.
WInAVR/ AVRstudio is used as IDE for writing program.
There are many ISP programmers (hardware) available in the market.
Starter kit helps you to experiment and test your program by downloading (flashing) the developed source code into the ATmega8 microcontroller.
Books, reference manuals and Computer based tutorial will help you to get started with the new and exciting world of microcontrollers.
There are several other microcontrollers available like PIC, 8051, ARM, etc.
Every family has some unique features to offer and you have to decide which feature you need the most.
Cost of the microcontroller is also an important factor in selecting. Other factors but important are availability of tools like compilers, IDEs, starter kits, programmers, books and reference material.
You may read more articles, free download of product schematics, datasheets at www.deccanrobots.com
Thank you for reading,
Pratik Deshpande
Compilers For 8051 Microcontrollers
Most computers in use today are embedded in some electronic device, from appliances to mobile devices. Such computers are called embedded systems. A key component in embedded system is a microcontroller. This is a microprocessor with emphasis on I/O operations. The role of microcontroller is to control electronic devices providing all necessary switching, measurements and communication with the world. Microcontroller is the brain of the device.
The first microcontrollers emerged in 1970s. They were 8-bit devices capable of running a program from internal ROM or external EEPROM memory. One of the popular microcontrollers was Intel 8051. Intel developed a family of microcontrollers named MCS-51, where 8051 was probably the most popular member. It is amazing that this architecture is still popular today. There are many manufacturers like Atmel, Silicon Labs and NXP that still use the 8051 core for their microcontrollers. This means that all the tools that were developed thirty years ago can, at least in theory, be still used today to develop programs for 8051-compatible microcontrollers.
The 8051 family of microcontrollers is special because it has many types of memory that need special instructions to access it. The basic memory is located in the DATA segment and most instructions can access it. The size of this memory segment is 256 bytes. The upper 128 bytes are reserved for Special Function Registers, memory mapped registers that control functions of the microcontroller. The lower half is divided into three parts. Addresses from 0 to 31 are memory addresses for registers R0 to R7 in 4 register banks (0 to 3). Addresses from 32 to 127 are general purpose memory locations with additional function of addresses from 32 to 47 which are also bit-addressable. Most 8051 microcontrollers (except the original 8051 microcontroller) have also additional 128 bytes of IDATA memory which is similar to DATA memory but can only be accessed indirectly. It is located at addresses from 128 to 255. Special instructions are needed for this type of memory. 8051 microcontrollers support also external memory located at XDATA segment. Its size is 64kB and can be accessed only indirectly with few special instructions. There is also a special bit-addressable memory where you can access individual bits (256 bits in total). The first half of this bit-addressable memory is general purpose memory while the upper half maps to bit-addressable special function registers.
This complicated memory model makes compiler construction a complicated task. But because the 8051 microcontrollers were well accepted in industry and they are also present in many hobby projects, quite a lot of companies decided to develop their own 8051 compiler. There are many commercial C compilers for 8051 microcontrollers available. Most of them are part of some commercial package together with integrated development environment (IDE), debugger and simulator. Among those the Keil IDE/compiler is probably the most popular. There is also one popular and free C compiler SDCC (Small Device C Compiler). SDCC is a retargettable, optimizing ANSI - C compiler that targets the Intel 8051, Maxim 80DS390, Zilog Z80 and the Motorola 68HC08 based microcontrollers. SDCC is Free Open Source Software, distributed under GNU General Public License (GPL).
The other hemisphere in 8051 programming is Pascal. Pascal programming language was designed by Niklaus Wirth in late 1960s. Its main purpose was to teach programming. The language itself is focused on structured programming and has many constructs for data structures. Borland Turbo Pascal was probably one of the most successful Pascal compilers around. It was very popular in 1980s and early 1990s. Its successor was Borland Delphi which is a visual rapid application development tool still in use today. Pascal is rarely used in embedded programming although there are compilers available also for AVR, ARM and PIC microcontrollers.
There is probably only one commercial Pascal compiler for 8051 microcontrollers, the KSC Pascal51. This clearly shows the market of C and Pascal compilers. However, there is also Turbo51, a free Pascal compiler for 8051 microcontrollers. Turbo51 is a fast single pass optimizing compiler with Borland Turbo Pascal 7 syntax and advanced multi-pass optimizer.
Similar situation is also with other popular microcontroller families like AVR, ARM and PIC. A plethora of C compilers are available and only a few Pascal or Basic compilers. Of course, we should not count assembly language compilers. These are the basic compilers for every processor or microcontroller. The most important thing with compilers is the code they generate. This should be highly optimized for size and speed. Comparing the code size of a program written for the same task in SDCC and in Turbo51 we can conclude that the result is not dependent on programming language. Either C or Pascal can be used to create a compact and optimized code. It is just the personal preference of the programmer what language he will use.
It is very interesting to compare generated code for some particular C or Pascal instruction, e.g. for 8051 microcontroller. We get practically the same microcontroller instructions. This is another confirmation that high level language is only a tool to describe the algorithm. It is the task of an optimizing compiler to generate individual microcontroller instructions that do what is needed.
Microcontroller market will continue to grow. One of the most important markets for microcontrollers is the automotive industry. It is the a driving force in the microcontroller market, especially at it's high end. Many microcontrollers were developed specifically for automotive applications. On the other hand almost every electrical device from toys to appliances uses some form of embedded system. The conclusion is that with microcontroller market growing also the need for high-quality embedded compilers will grow. This will lead to better compilers that will generate faster and more optimized code.
Igor Funa is a hobby programmer interested in computers, Pascal programming language, broadcasting, transmitting sites, DVB-T, and physics in general.
If you are programming for 8051 microcontrollers and like Pascal programming language then you should check Pascal compiler for 8051 microcontrollers.
Microcontroller Programming Tutorial Will Surely Assist You In More Ways Than One
This is undoubtedly the times of computer, where virtually everyone is dependent on it for one reason or the other. However another contrivance which is fast emerging as a hot favorite is the embedded system which is finding place in a lot of electronic goods in today's advanced epochs. If we were to describe the names of appliances and products where embedded systems play a crucial role, we will most probably run out of space. Microcontrollers are essentially microprocessors which are able to put to work input and output operations.
Apart from basic input output functions, microcontrollers also makes available facilities such as communication access, measurements and access to switching information. Amid other microcontroller, one name that stands out in the crowd is 8051 microcontroller. One must reckon that for programming microcontrollers in C, you need to have a fair amount of knowledge on the microcontroller itself and in such a scenario, microcontroller 8051 tutorial and microcontroller programming tutorial can come to your rescue.
The robustness of the C language has made it a much sought after alternative when it comes to microcontroller programming. Programming microcontrollers in C rather than some high level language is the trend in the industry and has its own reasons of being so. Microcontroller tutorial is essential to heighten your experience levels in this particular tool and you will be fascinated to find out new facts about its functionality such as it can operate at low frequencies such as 4 kHz and use small memory up to 4-bit words. The very fact that 8051 microcontrollers can efficiently carry out operations such as switching on/ off, button press, etc side by side remaining proficient makes them more alluring and lucrative.
The rising popularity of microcontrollers is alluring many a folks to undergo embedded microcontroller tutorials which will le them ride the wave and extract the max out of the situation. The best place to do some innate research pertaining to microcontroller 8051 tutorial or for that matter microcontroller programming tutorial is of course the word wide web which will let you search for a plethora of options when it comes down to embedded microcontrollers. Some of the most widely used appliances which make use of microcontrollers are: - automobile control systems, remote controls, medical devices, refrigerators, office machines, washing machines, toys, power tools, and a lot more. Once you gain experience and expertise in this specific field, there is no stopping you.
Embedded C tutorial for programming the 8051 and 8052 microcontrollers:- Embedded c Programming, Microcontroller Tutorial
8051 Microcontroller Tutorial Will Let You Go Deep Into The Concept Of Microcontrollers
In today's advanced epochs of state of the art technologies and avant-garde gadgets, embedded systems are playing an imperative role and are used in an assortment of appliances and gadgets. One quintessential facet of the embedded system is the microcontroller and amid other such microcontrollers, 8051 microcontroller is much sought after due to its vast applications and immense resourcefulness.
8051 microcontroller can be depicted as a microprocessor which proffers connotation to operations related to input and output. It takes into account switching information, communication and measurements and allows the electronic devices to access such information. One of the foremost and popular name sin the microcontrollers segment is the 8051 microcontroller.
The importance of such microcontrollers is alluring many a professionals to take up 8051 microcontroller tutorials and tutorials of c programming for microcontrollers. When it comes to manufacturers of 8051 microcontrollers which stand out from the crowd, some of the names which stand out from the rest are: Atmel, NXP and Silicon Labs. The memory structure of the 8051 microcontroller is a complicate done and you will definitely need an 8051 microcontroller tutorial to go deep into the concept.
It also calls for individual software instructions to get memory access and that too segment wise. In such a scenario, one could do with particular type of compilers which should be devised in a manner which will make accessible the memory. The widespread usage of 8051 microcontroller in the software and Information technology industry segment has brought into the scene, specific 8051 microcontroller compatible compilers. 8051 tutorial and C for microcontrollers are utterly imperative if you want to gain experience and expertise in this niche industry segment.
The best place to search for pertaining resources relevant to microcontrollers tutorial is undeniably the world wide web as with a bit of intricate research on the internet you will lay your hands on some edifying and quick witted results. Irrespective of the facts that whether you have prior experience or want to start from scratch these 8051 microcontroller tutorials are sure to escalate your expertise and experience levels.
These tutorials will make you acquainted with the fundamentals and 8051 microcontroller tutorials also envelop all the indispensable utilities of the range of micro-controllers which you can program your own micro-C programs. It also makes certain that the complete procedure of your understanding and finding out about is absolute fun, and is ultimate for electronics aficionados, engineers who are inclined towards microcontrollers and scholars desiring to becoming skilled at the C programming language in embedded milieu.
Embedded C tutorial for programming the 8051 and 8052 microcontrollers:- 8051 Microcontroller Tutorial, C for Microcontrollers
Saturday, May 28, 2011
INVESTMENTS IN SILICONE VALLEY
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Friday, May 20, 2011
Tuesday, April 5, 2011
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