Don't care value during simulation

[sebas]

Hi,

What happens to "X" - don't care values during simulation? To understand what I'm saying here's an example:
in a testbench there's the following statement:

we   = 1'hx;

then, lines after there's the following test:

 if (we) // do something//

(there's no else branch). What's the result of the if (we) test? is we interpreted as 0? what if we had an else branch also?

Thanks

 

[Alexium]

Good question, I'd like to hear the answer, too. My guess is "if" branch will NOT be taken, but that's totally a speculation on my part.

 

[mrflibble]

The if branch will not be taken, since 'X' does not evaluate to '1'.

But, you could always make a quick testbench to test such things out for yourself.