Basic parts of an embedded system

The embedded system as a whole system or part of a system consists of basic parts which it must contain to make it function properly. Each part of an embeded system as a specific function. For example, sensors, actuators, micro processors, memory, analog to digital converters form a part of the system. Below are parts of an embeded system with their functions and how they work.

  

• Sensors.

Sensors are electronic components that senses a change in environment or physical changes such as humidity, pressure, light, obstacles etc. It is also a transducer that converts physical signals or effects into electric signals which can be used by a microcontroller to actuate or control based on the signal produced.

•A-D converter.

This is also known as analog to digital converter.  It converts analog or electric signals from a sensor into digital signals in form of 0 or 1 (on and off respectively) which a microcontroller or processor can decode.

• Processor/ microntroller.

The processor also known as microntroller is the brain of an embedded system. It's responsible for control and operation of an embeded system circuit. It's use for processing signals and data from an analog to digital converter into commands at a very high speed.

Processors are the major parts in an embeded system that make response from scratch in digital form and processing of this response to produce output in real-time processing environment is performed using processors.

In embeded system design it's essential to have the knowledge of both microprocessors and microntrollers. A processor has two basic parts.

•Control unit: This unit in processors performed the program flow control operation inside an embedded system. The control unit also acts as a fetching unit for fetching the set of instructions stored inside a memory.

•Execution unit.

This unit is used for executing the various tasks inside a processor. It mainly comprises of arithmetic and logical unit (ALU) and it also includes a circuit that executes the instruction sets used to perform program control operation inside processor.

 

|Types of processor.

1. Application specific integrated circuits:

These are integrated circuits that are designed for a specific function. They can only be use for their designed function.

2.Application specific system processor(ASSP).

ASSP is an application dependent system processor used for processing signals of an embeded system. Therefore for different application performing task, a unique set of system processor is required.

3.Application specific instruction processor(ASIP).

ASIP is an application dependent instruction processor. It is used for processing the various instruction set inside a combinational circuit of an embedded system.

4.General purpose processor(GPP):

GPP is used for processing signals from input to output by controlling the operation of system bus, address bus and data bus inside an embedded system. Types of general purpose processors are;

Microprocessors, microcontroller, digital signal processor and analog signal processor.

•D-A converter.

A digital to analog converter is device that converts digital electric signals into it's equivalent analog signals for use in controlling analog components like actuators or for further processing.

• Actuators.

This are electronic components is for converting analog or digital signals ( mostly analog signals) into outputs such as motion.

They are also a comparators that are use for comparing the analog input signal level to desired output signal level for providing an error free output from the system. An example of an actuator is a servo motor.