MICROCONTROLLER ARCHITECTURE

MICROCONTROLLER ARCHITECTURE
                
                   There are two types of MICROCONTROLLER architectures. They are
                                      1. von Neumann
                                       2. Harvard

          1. Von Neumann Architecture

                             The von Neumann architecture allows for one instruction to be read from memory or data to be read/written from/to memory at a time. In other words, an instruction fetch and data operation cannot be performed at the same time. Instructions and data are stored in the same memory subsystem and share a communication pathway or bus to the CPU.

        2. Harvard Architecture

                                       The Harvard architecture alternatively consists of separate pathways or buses for interaction between the CPU and memory. The separation allows for instructions and data to be accessed concurrently. Also, a new instruction may be fetched from memory at the same time another one is finishing execution, allowing for a primitive form of pipelining. Pipelining decreases the execution time of one instruction, but main memory access time, in many cases, is a major bottleneck in the overall performance of the system. 

                             

PERIPHERALS AND ADVANTAGES OF EMBEDDED SYSTEM

PERIPHERALS USED WITH EMBEDDED SYSTEM

Embedded Systems communicate with the outside world via peripherals such as:

•   Serial Communication Interfaces (SCI): RS 232, RS 422, RS 485 etc.
•   Synchronous Serial Communication Interface: I2C, SPI, SSC and ESSI (Enhanced Synchronous Serial Interface)
•   Universal Serial Bus (USB)
•   Multi Media Cards (SD Cards, Compact Flash etc.)
•   Networks: Ethernet, Lon Works etc.
•   Field Bus: CAN Bus, LIN Bus PROFIBUS etc.
•   Timers: PLL (s), Capture/Compare and Time Processing Units
•   Discrete IO: aka General Purpose Input/output (GPIO)
•  Analog to Digital/Digital to Analog (ADC/DAC)
•   Debugging: JTAG, ISP, ICSP, BDM Port, BITP, and DP9 ports.

      

         

       ADVANTAGES OF EMBEDDED SYSTEM

              

•        Design and Efficiency
•         Cost
•         Accessibility
•         Maintenance
  
  
  

 

COMPONENTS OF AN EMBEDDED SYSTEM

COMPONENTS OF AN EMBEDDED SYSTEM
                       
                              There are two parts in an embedded system. They are

                                                1. HARDWARE PART
                                                2. SOFTWARE PART


 1. HARDWARE PART

                              This hardware part contains controllers, sensors, power supplies, and output devices.

2. SOFTWARE PART
   
                              This is the coding part. In this part we can write the source code to make the conrtollers work. It can be written any languages namely c,c++,python,and so.

EMBEDDED SYSTEM

DEFINITION OF AN EMBEDDED SYSTEM

                  An embedded system is a computer system designed for specific control functions within a larger system, often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal computer (PC), is designed to be flexible and to meet a wide range of end-user needs.

Evolution of Embedded System

                         The Minute-man I & II missiles are intercontinental ballistic nu-clear warheads, produced by Boeing in the 1960’s.Due to the large quantities of ICs used in the guidance system of Minuteman II missiles, prices for ICs fell from 1000$ each to 3$ each. This lead to wide adoption of embedded systems in consumer-electronics in the 1980’s.

                      Nowadays embedded systems can be found in devices from digital watches to traffic control systems. The broad range of applications with totally different requirements leads to various implementation approaches. The range of hardware used in embedded systems reaches from FPGAs to full blown desktop CPUs which are accompanied by special-purpose ICs such as DSPs.