[AlexH]

Hi guys,

I'm having trouble with an assignment. My job is to design a circuit (we are using a circuit simulator program that the professor wrote) that will count the number of times that 1 appears in an 8-bit binary number, and output a 4-bit number containing the number of 1s. For example, if you input 01101011 you should output 0101 (5).

So far I have setup an input, a 8-bit debundler to seperate the different bits in the input, and a 4-bit bundler to output the number of 1s. I was thinking I need to use some half-adders or full-adders to add up the number of 1s.

Thanks for any ideas.

[BigAnt]

What are the constraints on the problem??

I mean could you write an 8 input/4 output truth table and use this??

[AlexH]

I can use only basic logic gates (AND, OR, XOR, NOR, etc). I can't use adders, multiplexors, decoders, state machines, truth tables, registers or any memory.

I CAN use these elements if I explicitly show the internal circuitry. I can't just draw the symbol for a multiplexor and use that.

This post has been edited by AlexH: 23 February 2009 - 03:42 PM

[numerical_jerome]

Quote

I CAN use these elements if I explicitly show the internal circuitry.

In which case your next best step might be designing a reasonable D-flipflop

-Jerome

EDIT:

and maby use a longer ring oscillator for the clock :-)

This post has been edited by numerical_jerome: 23 February 2009 - 08:26 PM