machines can be classified using two different models:
(1) As Moore machines.
(2) As Mealy machines.
Following is an example of a Moore machine, named in honor of Professor Edward F. Moore (1925-2003) who proposed this mathematical model for the study of sequential machines:
Moore machine is distinguished as a machine in which each circle in addition to specify the state of machine specifies the output or outputs that are produced in the state. The outputs are not necessarily equal to the state of the machine. May be, as in the case of the binary counter count-up of 4 bits mentioned previously. But if each of the terminals Q of said binary counter is connected to a logic circuit that converts the set of outputs in a different set of outputs, then it is obvious that the output produced will be different from the states of the machine. The notation used within each circle has a shape as 10/11, wherein the first binary word (10) indicates the machine status and the second binary word (11) indicates the output of the machine which we call z. In the example given for a Mealy machine, we have a machine we can assume it was constructed with two flip-flops. According to the diagram, this machine can be in one of three states:
q1q0 = 00 giving an output of z1z0 = 01q1q0 = 01 giving an output of z1z0 = 11q1q0 = 10 giving an output of z1z0 = 11Como in case of a finite state machine we saw ordinary at first, the arrows outside the states (circles) that operated out of a state are the entry or entries placed in the machine at any given time. In this case, we have a Moore machine that also has a single entrance designated as x. The behavior of this machine depending on the value of the input x q = q1q0 state in which the machine is is similar to what we saw before, except that if the machine is in the state q1q0 = 00 have an output z = z1z0 = 01.
Following is an example of a Mealy machine:
Mealy machine is distinguished as a machine in which when the machine is in a state, then applying some input to transition to another been producing some output as a result of the transition. The notation used in the vertices is shaped like 1 / 0, where the first binary word (1) indicates the input given to the machine and the second binary word (0) indicates the output produced in carrying out the transition from one state to the example mentioned siguiente.En for a Mealy machine, we have a machine that once again we can assume that it was constructed with two flip-flops.
According to the diagram, this machine can be in one of three states:
q1q0 = 00q1q0 = 01q1q0 = 11 In this case, we have a Mealy machine that also has a single entrance designated as x. The way to read this state diagram is as follows: If the machine is in the state q1q0 = 00, then according to the notation at the top, 1 / 1, if it is applied to the machine input 1 then the next "clock tick" transition to state q1q0 = 01 producing an output of 1. And conversely, if you are in that state of q1q0 = 00 and is applied to the machine an input of 0, then the next "clock tick" the machine transitions to state q1q0 = 11 producing an output of 1.Se can prove, with mathematical rigor that any Moore machine is equivalent to a Mealy machine and vice versa. By this we mean that given a Moore machine can produce a Mealy machine, or given a Mealy machine can produce a Moore machine such that both have the same sequence of outputs q if both are fed the same sequence as its inputs x. The demonstration to convert a Mealy machine in Moore machine requires increasing the number of estados.De interest to us is the fact that there are computer programs that allow us to convert any finite state machine in a logic circuit composed of basic logic functions and flip-flops.
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