Mutiplexer giving high impedance while connected serially to a D-Flip Flop

--- Quote Start ---

Hi!

The "always@(posedge clk or negedge reset)" statement should be "always@(posedge clk or posedge reset)" as you trigger on a rising reset input.

And you should use a complete sensitivity list (all signals at the right side of "=") at:

"always@(sel)". Or the simple way: "always @*"

Use "=" instead of "<=" in combinatorial blocks ("always @*").

With these changes your output should be 1'b0 or 1'b1 instead of x.

--- Quote End ---

Thanks a lot!! Now the code is working perfectly