Adds behaviour to the 4b port implementations of frame_master and _slave to correctly operate in the event that the user specifies a nulled input or output port.
This alters test behaviour - if NUM_IN or NUM_OUT are set to 0 for the 4b port tests, these will be set to null in the test.
This introduces a test escape - no tests are now performed for the 4b implementation for non-null but empty input or output port lists. This should be rectified (along with dedicated tests written for both behaviours) in future work.
Adds behaviour to the 4b port implementations of frame_master and _slave to correctly operate in the event that the user specifies a nulled input or output port.
This alters test behaviour - if NUM_IN or NUM_OUT are set to 0 for the 4b port tests, these will be set to
nullin the test. This introduces a test escape - no tests are now performed for the 4b implementation for non-null but empty input or output port lists. This should be rectified (along with dedicated tests written for both behaviours) in future work.Closes #114