How to Select Microcontroller?

In this tutorial we are going to learn about How to Select Microcontroller?

  • Selection of microcontroller unit (MCU) for your application is one of the critical decisions which control the success or failure of your project.
  • In market have thousand different type of microcontroller , each of them with  unique feature or competitive advantage from form factors , to the capacity of the RAM and ROM that makes then fit  for certain application and unit for certain applications.
  • There are five major 8 bit microcontrollers. They are Free scale semiconductor’s 68HC11/68HC11, 8051 and variants, Atmel’s AVR, Zilog  Z8 and PIC from microchip technology. Each of these microcontrollers has unique instruction set and register set there are not compatible with each other.
  • There are also 16 bit and 32 bit microcontrollers made by various manufacturers.
  • With these different microcontrollers what is the criteria designers consider in selecting one?

             General Outline of Main Criteria

  • Suitability for the application system
  • Like that can it be done with a single –chip MCU or at most a few additional chips?
  • Does it have required number of I/O (input/output) pins/ports?-for example, too many=excessive cost.
  •  Does it have all the other required peripherals , such as serial I/O, random-access memory (RAM) read-only memory (ROM) analog –to –digital (A/D), digital –to-analog (D/A), timers, capture compare and PWM module (CCP)etc.?
  • Does it come in a 40 pin DIP (dual in line package) or a QFP (quad flat package) or some other packaging format? It is important in terms of space assembling and prototyping the end product.
  •  Does it have necessary communication interacts? It is for peripherals such as USB, I2C,SPI UART, and so on.
  • If the CPU (central processor unit) core have the correct throughput?-for example, computer power, to the handle the system for the chosen implementation language? too much is wasteful, and too little will never work.
  • Is the MCU affordable? What is cost per unit? This is important in terms of final cost of product.
  •  Use of upgrade to higher performance or lower power consumption versions.

      Availability

  • Is the deice available in sufficient quantities? this is important for a company making a product on large scale.
  •  Is the device in production today? This is important for demand in future also. Currently 8051family has the largest number of diversified (multiple) suppliers. Several companies produce 8051 family members currently. Microchip technology is also produce the PIC and AVR microcontrollers in large number.

     Development support

  • Is development support available?

    a) Assemblers

    b) Compilers

    c) Debugging tools

  • Evaluation module (EVM)
  • IN-Circuit emulators
  • Logic analyzer pods
  • Debug monitors
  • Source- level debug monitors
  • On –line bulletin board service (BBS)
  • Real-time executives
  • Application examples

          Bug reports

  • Utility software, including “free ”assemblers
  • Sample source code

          Application Support

  • Required Specific group who does nothing but applications support?
  •  Application engineers, technicians, or marketers?
  •  How knowledgeable are the support personnel? Are they truly interested in Helping you with your problem you with your problem?
  • Telephone and/or fax support?

       Note :

  • Free scale semiconductor (Motorola),Atmel , Zilog and microchip technology have all dedicated massive resources to ensure wide and timely availability of their products because their products are stable , mature and single sourced.
  • 8051 family and its variants are also have begun to sell field programmable gate Array (FPGA)and application  specific integrated circuit (ASIC) libraries  for different microcontrollers .

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