VHDL Sensitivity List

The process will execute if there is a change on any of the signals in the sensitivity list

process (SEL, A, B, C)
begin
  if SEL = '1' then
    OP <= A and MASK;
  else
    OP <= B;
  end if;
end process;

NOTE: Only asynchronous inputs go in the sensitivity list.

Reference

http://www.doulos.com

This blog post contains notes taken when working through the Doulos Pacemaker tutorial.   Any content copied from the tutorial has been reproduced with permission.  http://www.doulos.com.