| OCR Text |
Show 31 whether the state-machine is in a stable state (a state with no active transitions) or in the process of performing a state-to-state transition. If the capability of changing inputs either during a stable state or during a state-to-state transition exists, the Simulator bas effectively allowed non-fundamental mode arrival of input signals to the machine. At any given time and for a given control-unit (or set of interacting state-machines), there will be a set of currently active states (a subset. of the set of all states) and a set of currently inactive states (also a subset of the set of all states), the union of which is the set of all states. A subset of the inputs to the control-unit Will be true and anct.her- will be false. A subset of the outputs will be true and another subset will be false. Implicit in the use of these sets, and consistent with functional Simulation, is the assumption of instantaneous rising and falling of inputs and outputs. .These six subsets constitute the knowledge of the total state of the control-unit. From these six sets and a knowledge of the interconnection of states, transitions, inputs and outputs, the next state of the control-unit can easily be obtained. Attempting to resolve the next state of the control-unit requires mapping the set of currently active states in the machine which are subject to a valid transition into a set of next active states and removing t ncse states which did transition to a next state from the set of currently active states. When all states in the set of currently active states have been resolved, a new set of currently |
