[vhdl-200x-ft] comments on ft25

Suppose you declare

variable a, b : std_logic_vector(1 downto 0);

...

case (a & b) is

how does an analyzer differentiate between a 4 wide std_logic_vector and a
2 wide array of 2 wide std_logic_vector? In other words do the when
expressions look like

when "1000"

-or-

when ("10", "00")

?

Concats are not deterministic without some contextual type or subtype.
The case expression does not have any
such context and thus an analyzer cannot distinguish. Is the suggestion
that in those cases, a qualified expression IS required?

karl
Received on Mon Jul 26 14:02:18 2004