Basics of Embedded Designs

Basics of Embedded System Design :

There is no perfect definition for an embedded system. It can be defined is several ways.

Generally it is defined as computing system, which is dedicated to some specific task with limited set of resources. It can be thought of as a custom made computer tailored for our requirements.

So where can you find an embedded system. You can see it anywhere between the toys you had used during your childhood to the most modern space shuttle. A coffee vending machines a best example of an embedded system that you see in your everyday life. It consists of a set of buttons from where you can enter your choice for a cup hot coffee or milk. In your household, washing machine is another example, where you just have to set the timer for rinsing or drying. After that time, it will automatically stop the current activity.

So what’s makes up these things and why it is called an embedded system?

An embedded system is an electronic system that contains both software and hardware. A microcontroller or microprocessor is the heart of an embedded system. DSP (Digital Signal Processors) processors or ASIC (Application Specific Integrated Circuits) can be used instead of microcontroller, depending upon the requirements.

So what are all these stuffs called microcontroller, microprocessors, DSP, processor etc??

Microprocessor - It’s an electronic chip capable of computing or processing your data. It consists of an ALU (Arithmetic Logical Unit), Accumulator, and Registers etc. The processing of data is done by the ALU. An external memory (ROM/FLASH) had to externally interfaced to the microprocessor to store the software. The microprocessors carry out its task by executing the program in the ROM.

Various vendors like, Intel, Motorola, and Philips etc manufacture microprocessors

The specification of a microcontroller is it word size, means how much bits it can process at a time. The world’s first microprocessor was Intel’s 4004, which is a 4 - bit processor. It hasn’t gained much popularity and market. The Intel’s 8085 was the first 8 - bit processor to become commercially successful. It was first developed around some 3 decades ago. It is used in applications where the data to be processed in not much than 8 bits at a time. E.g. Coffee Vending Machine

Another important factor to be kept in mind while selecting the processor is its clock speed. The clock speed is a measure of a microprocessor’s speed. If higher the clock speed, then lesser is time you need to complete a task, but at the same time, the hardware will become susceptible to unwanted noise, adding too much of its cost in hardware design.

Then it was the era of 16 - bit processors, Intel’s 8086 and 8088.

Now the computer system in which you are reading this text is most probably and 32-bit processor of Intel or AMD. Technology has advanced out of bounds.

So what should I look for, if I want to make an embedded system- an 8 bit or a 32 bit??
Selection of a processor is according to your application and other factors like the availability of compilers/assemblers, your expertise, and cost.

Microprocessor - It’s an electronic chip capable of computing or processing your data. It consists of an ALU (Arithmetic Logical Unit), Accumulator, and Registers etc. The processing of data is done by the ALU. An external memory (ROM/FLASH) had to externally interfaced to the microprocessor to store the software. The microprocessors carry out its task by executing the program in the ROM.

Various vendors like, Intel, Motorola, and Philips etc manufacture microprocessors

The specification of a microcontroller is it word size, means how much bits it can process at a time. The world’s first microprocessor was Intel’s 4004, which is a 4 - bit processor. It hasn’t gained much popularity and market. The Intel’s 8085 was the first 8 - bit processor to become commercially successful. It was first developed around some 3 decades ago. It is used in applications where the data to be processed in not much than 8 bits at a time. E.g. Coffee Vending Machine

Another important factor to be kept in mind while selecting the processor is its clock speed. The clock speed is a measure of a microprocessor’s speed. If higher the clock speed, then lesser is time you need to complete a task, but at the same time, the hardware will become susceptible to unwanted noise, adding too much of its cost in hardware design.

Then it was the era of 16 - bit processors, Intel’s 8086 and 8088.

Now the computer system in which you are reading this text is most probably and 32-bit processor of Intel or AMD. Technology has advanced out of bounds.

So what should I look for, if I want to make an embedded system- an 8 bit or a 32 bit??
Selection of a processor is according to your application and other factors like the availability of compilers/assemblers, your expertise, and cost.

Digital Signal Processor - A DSP processor is used in applications where analog signals are to be processed in real time manner such as in our mobile phones. The main difference between a DSP processor and a microcontroller is that the former contain a dedicated Shifter and MAC (Multiply and Add). An ordinary microcontroller takes more time to do this operation. A DSP processor also supports advanced mathematical operations like transforms, convolutions, etc.

So when dealing analog signals and it is to be processed digitally, the right choice should be DSP processor.

Analog Devices and Texas Instruments manufacture DSP processors.

Eg
ADSP21XX is a DSP processor by Analog Devices.