| OCR Text |
Show 40 true. These will remain true until this state is made inactive after a transition. Those which are uncondi;ionally set or reset (by SET or RESET) are respectively made true or false. These will remain true or false until operated upon by another state or transition. Any conditional outputs are changed by evaluating the associated boolean expression and performing the same operations as on unconditional outputs when the condition is true. _ Second, when performing a transition, the status of each output controlled by that transition 1s reviewed in the same way as those controlled oy states were when the state was first entered. Third,·when leaving a state (making the state inacti ve) those outputs whieh were being unconditionally or conditionally held both under control of the state and of the transition must be made false, with the exception of those which are being held by other state or transition. The output updating mechanism is perhaps the most complex in t.he : simulation of speedindependent one-hot state-machines. The above algorithms describe the basic behavior of the functional Simulator. As described, the simulator has not kept track of any simulation history. Adding the history mechanism merely implies updating a history file each time a transition occurs or a set of inputs changes. In addition, given the history mechanism, one can effecti vely reverse the simulation procedure by restoring the entire ntrol-unit to a previous state, consisting of state values, input and output values'. Such backup and history mechanisms exist in ASSASSIN. The history used for backup is kept on the property list of |
