General Description: Some internal signals that are outputs of combinatorial logic will not shows up as a selectable signal in the simulator due to the XVHDL compiler changing the name of the signal.
Solution
To force Metamor (the XVHDL compiler) from renaming the signal use the 'critical' attribute, as shown below.
Note that the Metamor library should be declared at the top of the VHDL file:
library METAMOR; use METAMOR.attributes.all;
The attribute should be used as follows, and should be placed before the 'begin' keyword in the architecture section.
attribute critical of <signal name>: signal is true;