cpu for microcontroller

Discussion in 'General Electronics Chat' started by vead, Nov 16, 2013.

  1. vead

    Thread Starter Active Member

    Nov 24, 2011
    621
    8
    I want to design 8 bit micro controller for my basic understanding(paper work) i know microcontroller is made mainly with cpu , mememory and peripheral so I have start to make cpu
    cpu is made with alu and control unit
    alu is use to perform arithmetic function and logic function
    so i use AND OR NOR NAND NOR IC to create logic function
    and to create arithmetic function I use adder subtractor
    and for control unit I use multiplexer decoder and counter

    now I can make cpu with this ICs But i don't understand how many bit are requrie to make alu conrol unit. suppose I want to make 8 bit microcontroller then how many bit are require to make cpu and same things for cpu I want make alu for 8 bit cpu then how i decide how many bit are require to make alu
     
  2. ScottWang

    Moderator

    Aug 23, 2012
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  3. Brownout

    Well-Known Member

    Jan 10, 2012
    2,375
    998
    The short answer is 8 bits. But CPU architecture differs from one unit to another. For example, a mulitplier might be 16 bit, although outside of the CPU, all data transfers are 8 bit. The first thing is to decide upon an architecture for your CPU.
     
  4. vead

    Thread Starter Active Member

    Nov 24, 2011
    621
    8
    thanks guys but I haven't find particular answer
    In theory i know gates IC like AND NOR NOT NAND NOR XOR XNOR
    flip flop D ,T , JK SR I know counter shift register memory a
    I know how the alu circuit make , how the control unit make
    now i know how to make cpu for controller I need AND OR NOR NAND NOR IC to create logic function
    and to create arithmetic function I use adder subtractor
    and for control unit I use multiplexer decoder and counter

    but I am having problem I know I want to make 8 bit but cpu how to decide bit for other like counter decoder alu I can check datasheet but I want to particular reason
    can anyone help me
     
  5. WBahn

    Moderator

    Mar 31, 2012
    17,715
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