microcontroller

WHAT IS MICRO CONTROLLER:-

                Micro controller may be  called """"""computer on chip""""""" since it has basic features
of micro controller with internal  ROM, RAM, PARALLEL and  SERIAL PORTS with in single chip.


                             OR
   Micro processor with memory and ports is called as  micro controller

APPLICATION:


**Washing machines,
**AC'S
**ROBOTICS
**INDUSTRIES

TYPES OF MICRO CONTROLLER:

                                       We have so many micro controllers.


The 8051 Micro controller is first micro controller of MCS-51 family introduced by INTEL corporation at end of 1970's.

              It 8 bit micro controller, means it can read, write and process 8 bit data. this is mostly used in robotics and industries etc.....

 FEATURE:

** It is a 40 pin IC/dip
**   It has 4 i/o ports
**   1 serial port
**  128 byte RAM
**  4KB ROM
**  2 TIMERS
** 5 INTERRUPTS

WE WILL DISCUSS SLOWLY one by one


 RAM: ( 00 h - 7f h)

          Micro controller 8051 has 128 byte  Random Access Memory for data storage. RAM is a volatile memory. RAM is used to storing the when execution time.
          RAM consists following  blocks.
             1.register banks                     ( Bank 0, Bank 1, Bank 2, Bank 3 )
             2.stack                                   (  Bank 1, Bank 2, Bank 3)
             3.bit addressable RAM         (  20 h - 2f h)
             4.Scratch pad RAM              ( 30 h - 7f h)





* RAM is a volatile memory. Generally RAM can be used for storage of data at the time execution.

* In  8051, RAM has 256 byte of memory. In which  128 byte is for user purpose.

i.e
       1. BANK  REGISTERS {0,1,2,3}

       2.BIT ADDRESSABLE RAM

       3.GENERAL PURPOSE RAM

* Remaining 128 byte used for SPECIAL FUNCTION REGISTERS {SFR}

*In SFR consists 21 SFR registers

    1. PORT REGISTERS                                 {0,1,2,3}

    2. INTERNAL TIMER REGISTER           {TCON, TMOD,TL0,TL1,TH0,TH1}

     3.POWER  CONTROL REGISTER          {PCON}

     4.SERIAL PORT REGISTER                    {SCON,SBUF}


     5.INTERRUPT REGISTER                        {IE,IP}

     6. STACK P[OINTER                                   {SP}

     7.DATA POINTER                                      {DPH,DPL}

      8.ACCUMULATOR                                   { A }

     9. B REGISTER

     10. PROGRAM STATUS WORD               {PSW}


* Up to 64k bytes of external RAM memory  is supported. This is read-write memory and it is available for storage of data.


ROM:

          In 8051, 4 KB read only memory(ROM). It is useful for storing program. It is a Non volatile memory. We can interface up to 64 KB ROM memory externally.