is_x() - std_logic_1164

For a std_ulogic or std_logic argument, this function returns true if the value is one of the undefined values ( 'U', 'X', 'Z', 'W', '-'). It returns false otherwise.

Syntax

function is_x ( s : std_ulogic ) return boolean;
function is_x ( s : std_ulogic_vector ) return boolean;
function is_x ( s : std_logic_vector ) return boolean;

Example

Output / Return Value

Limitations

Alternatives / See Also

Reference

https://www.cs.sfu.ca/~ggbaker/reference/std_logic/1164/is_x.html