or_reduce functionality

what is the functionality of "or_reduce" f开发者_开发知识库unction in VHDL ?

crazyscot is quite right. Here's a precis:

It takes a std_logic_vector and returns the result of using the VHDL OR operator to or all the bits together. So if there's a X, Z, U etc in the vector, you'll get the "strongest" of these back.