Читать книгу Digital System Design using FSMs - Peter D. Minns - Страница 29

In the previous frames we have considered the flip‐flop output patterns. These are often referred to as the secondary state variables (SSVs) (Figure 1.16).

Figure 1.16 Block diagram showing secondary state variables in the FSM.

They are called ‘secondary state variables’ because they are (from the FSM architecture viewpoint) internal to the FSM (i.e. secondary not primary). If we consider the outside world inputs and outputs as being primary then it seems sensible to call the flip‐flop outputs SSVs (and state variables because they define the states of the state machine).