The number of states in a sequential circuit is closely related to the complexity of the resulting circuit. It is therefore desirable to know when two or more states are equivalent in all aspects. The process of eliminating the equivalent or redundant states from a state table/diagram is known as state reduction.
What is an implication chart?
Implication charts are a common way of reducing an FSM. It works by finding states that have identical transitions to each other. It is a graphical method suitable for fast computation by hand.
How can we reduce the state table?
To minimize the number of states, we will identify “equivalent states” and eliminate any redundancy found. Two states are equivalent if they have equivalent next states and the same output for each possible input condition.
How does state Reduction help to design a sequential circuit?
State Reduction: The reduction of the number of flip-flops in a sequential circuit is referred to as the state reduction problem. State-reduction algorithms are concerned with procedures for reducing the number of states in a state table, while keeping the external input-output requirements unchanged.
What are the benefits of state reduction?
State reduction technique also allows you to be less meticulous in obtaining the initial finite state machine description. If you have introduced a few redundant states, you will find and eliminate them by using the state reduction technique introduced next.
What is state reduction and assignment?
The problem of state reduction is to find ways of reducing the number of states in a sequential circuit, while keeping the external input-output relationships unchanged. …
What is state reduction and state assignment?
What is ASM chart?
An ASM chart is a method of describing the sequential operations of a digital system.
How do I change the next state of the implication table?
You can change the Next State and Present Output of the Next State Table. Press the Calculate button to re-evaluate the Implication Table using your modified values Draw the blank implication table so that it contains a square for each pair of states in the next state table.
How does the implication chart method work?
The implication chart method uses a graphical grid of sorts to systematically find equivalences among the states. The implication chart assists in keeping track of any implications such as, for example, c-d and e-f are implied pairs for a-b in Table 4 below:
How many states are there in the implication chart?
In this particular example, the number of states was reduced from fifteen (15) to seven (7) states. This literally amounts to a reduction of eight (8) states and the elimination of one flip-flop for the final design. The implication chart method uses a graphical grid of sorts to systematically find equivalences among the states.
What is the difference between implication chart and subsequent partitioning?
The implication chart uses a graphical grid to help find any implications or equivalences and is a great systematic approach to reducing state machines. Successive partitioning is almost a cross between row matching and implication chart where both a graphical table and equivalent matching is used.
