Hi everyone,

I need to implement 3x8 decoder using both 1x2 and 2x4 decoder. I tried too much but I couldnt solve it.
I found a solution but it does not contain 1x2 decoder.

Do you have any ideas?

Thanks in advance.

 

You need to show YOUR attempt to solve YOUR homework problem. That gives us a starting point for discussion in OUR attempt to guide YOU toward finding your own path to the correct solution.

 

Do the 2x4 decoders you are using have output enable inputs on them?

 

You need to show YOUR attempt to solve YOUR homework problem. That gives us a starting point for discussion in OUR attempt to guide YOU toward finding your own path to the correct solution.

I found but it is not correct. I used only 2x4 but I must use 1x2 and 2x4.

Do the 2x4 decoders you are using have output enable inputs on them?

There is no information about it. Actually, I dont know too much about the one which has enable input, I tried to implement it using decoders which has no enable input.

 

Again, you need to show YOUR best attempt. It doesn't have to be correct, but it does have to be there.

If your 2x4 decoders have enable inputs, then the solution is trivial. If they don't, then it is all but impossible. You need to find out what your available resources are.

 

There is no information about it. Actually, I dont know too much about the one which has enable input, I tried to implement it using decoders which has no enable input.

Few hints:
1. Check with whoever gave you the homework if the decoders have enable input or not. My guess is that they do. This makes things easier. If you don't ask and assume yourself, make sure to state it in the beginning of your answer.

2. You can implement a 1x2 decoder with enable input using a single 2x4 decoder with no enable input. Furthermore, it can be active high or active low enable, as you wish.

3. Nobody said that you need to use all the output of all the decoders you use, especially if your decoders do not come with an enable input.