Relational Operators (9.2.1)

The software supports these relational operators.

Operator Description Usage Type Returned
= a is equal to b a = b Boolean
/= a not equal to b a /= b Boolean
< a less than b a < b Boolean
<= a is less than or equal to b a <= b Boolean
> a is greater than b a > b Boolean
>= a is greater than or equal to b a >= b Boolean
?= a is equal to b a ?= b Bit or std_logic
?/= a is not equal to b a ?/= b Bit or std_logic
?< a is less than b a ?< b Bit or std_logic
?<= a is less than or equal to b a ?<= b Bit or std_logic
?> a is greater than b a ?> b Bit or std_logic
?>= a is greater than or equal to b a ?>= b Bit or std_logic

In this example, the output is 1 if A(14) is equal 1 and B(14) is equal to 1; otherwise the output is 0.

output <= A(14) ?= '1' and B(14);