Digital Logic

Thread Starter


Joined May 21, 2006
Good evening...i am new to digital logic and i would appreciate any help...
I have 2 problems :

1st problem : I want to design a circuit with counters which will divide the clock pulse so the circuit operates to 1/4 ...(the clock pulse divided by 4)

2nd problem : I want to design a serial circuit 2-bit full adder using D-Flip-Flops...

Each problem is different....Thank you for your time...


Joined Apr 20, 2004

The first function is just a divide-by-two followed by another divide-by-two. A couple of toggling flip-flops will do the trick.

As for the full adder, no can do with just D flip-flops. Look up the data sheet for any full adder chip and you willl see the need for additional logic functions. Hint - don't reinvent the wheel, follow the design of an existing adder.


Joined Nov 17, 2003
Further to hgmjr's post above, you may wish to embelish how you intend to achieve your objectives.

Firstly, how do you intend to implement your design - are you going to use a high-level hardware decription language to implement your design on a PAL/FPGA type device, or are you wanting to go the full hog and implement a low-level design using descrete components? I, like any other sane person, would recommend the first option in which case you will need to select your hardware decription language of choice (e.g. VHDL, Verilog etc). At which point, we can give you some ideas on how to go about achieving your objectives.