re:textbook problem

Thread Starter

vishwanath.barath

Joined Oct 23, 2008
3
i have exam tomorrow.urgent help required

the problem is

draw the logic diagram of a 4 bit register with 4 D flip flops and four 4 to 1 multiplexers with mode selection inputs s1 and s0.The register operates according to the following function table.

S1 S0 Register operations
0 0 No change
0 1 Complement the four outputs
1 0 Clear register to 0(synchronous with the clock)
1 1 Load parallel data
 

beenthere

Joined Apr 20, 2004
15,819
The Homework Help section asks that you post up the work you have done so we can see it and find where you went wrong, or suggest better approaches. We will not do all your work for you, no matter how little time is left before it must be submitted.

If you are in doubt about how to structure your post and what to include please read this thread.

Thank you.
 

veritas

Joined Feb 7, 2008
167
For a second I was thinking "You only need one 4-to-1 multiplexor," but then I realized you probably can't use one with multiple-bit inputs/output.

For this task, you can compute each of the 4 potential inputs in parallel. The 4-to-1 multiplexors will select between them to get the actual new input for each bit.

I would suggest designing a diagram for a single bit and showing us your work.
 
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