I had a statement like :
if (`TB.myDesign.timer.en === ‘bx)
$display (” Timer Enable has become x”);
else
$display (“Timer Enable is not x”);
Upon running simulation, I found the signal timer.en to be x in the waveform and yet, the log showed :
Timer Enable is not x.
I was baffled for a while, and then figured that the tool was unable to process a statement with no information of bit-size (‘bx) and thought I’ll change it to 1‘bx and voila ! It worked !
Solution : So, make sure you specify the bit size. If it’s a vector [31:0] you need to write 32’bx.