Left Shift Register with T Flip Flops.

Discussion in 'Homework Help' started by sriley, Mar 14, 2012.

  1. sriley

    Thread Starter New Member

    Mar 14, 2012
    4
    0
    Hi!
    I wanted to ask if it is possible to design circuit for
    parallel-in/serial-out left shift register with T Flip flops?
    S.R
     
  2. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    In theory, yes.

    But using anything else than a D-FF or even a JK-FF would be unnecessary trouble.
     
  3. sriley

    Thread Starter New Member

    Mar 14, 2012
    4
    0
    So when i want to draw a circuit...i just have to draw it
    with JK flip-flops applying +5 volts to them(to be in toggle mode)
    ?
     
  4. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    You will need to use a logic gate to convert the T-FF into a D-FF.

    Why do you need to use a T-FF anyway?
     
  5. sriley

    Thread Starter New Member

    Mar 14, 2012
    4
    0
    It's for my homework assignment and i can't figure out it...
     
  6. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    Assuming you can design a shift register out of a D-FF, let's focus in converting a T-FF into a D-FF.

    The line of thought is to put a logic gate between the T-FF and its input, so that it behaves as a D-FF.
    The D-FF is supposed to store whatever it is given to it in the next cycle. That said, let's look at an example:
    If a T-FF has 1 stored in it, and receives a 1, it should retain that value. Thus, it should receive a 0 to its T input.
    If it has 0 stored and it receives a 1, it should toggle, and thus receive a 1 to its T input.

    Complete a table with all those 4 cases and post it. The choice of the 2-input logic gate should be apparent by then.
     
  7. sriley

    Thread Starter New Member

    Mar 14, 2012
    4
    0
    Well my teahcer told me that i shouldnt convert T-FF into D...
     
  8. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    Has he given you another hint? There might be an alternative way. It would involve building an Finite State Machine cell, which would implement the Shift, Load and Hold functions of the register.

    Basically, use the T-FF to create the cell, in pretty much the same way you use the D-FF. It's just that the functions will be different.
     
Loading...