Hello i need to add more gating to this binary counter i created to construct a decoder that will illuminate a LED when the binary equivalent of 12 is reached. any ideas?

 

Probably a 4-input NAND with x0',x1',x2,x3 [LSB to MSB count bits] as input and the output sinking the LED from +5V

 

Think about what the counter outputs look like when the count is 12.

 

the output i get in multisim is like a lowercase u. :/

 

Which output? The NAND's output as proposed by t_n_k? Is that its behaviour during one clock cycle and a tad more? It seems natural to me since you want to get 0 on the count of 12, and the NAND gate does just that, with a bit of capacitive delay of course.

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