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Topic: Mealy machine


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In the News (Sun 21 Apr 19)

  
  Mealy machine - Wikipedia, the free encyclopedia
In the theory of computation, a Mealy machine is a finite state machine where the outputs are determined by the current state and the input.
In contrast, the output of a Moore finite state machine depends only on the current state and does not depend on the current input.
However, every Mealy machine is equivalent to a Moore machine whose states are the union of the Mealy machine's states and the Cartesian product of the Mealy machine's states and the input alphabet.
en.wikipedia.org /wiki/Mealy_machine   (244 words)

  
 Moore machine - Wikipedia, the free encyclopedia
In the theory of computation, a Moore machine is a finite state automaton where the outputs are determined by the current state alone (and not on the input).
The name Moore machine comes from that of their promoter: Edward F. Moore, a state machine pioneer, who wrote Gedanken-experiments on Sequential Machines, pp 129 – 153, Automata Studies, Annals of Mathematical Studies, no. 34, Princeton University Press, Princeton, N. Most electronics are designed as clocked sequential systems.
The number of states in a Moore machine will be greater than or equal to the number of states in the corresponding Mealy machine.
en.wikipedia.org /wiki/Moore_machine   (393 words)

  
 Finite state machine - Wikipedia, the free encyclopedia
A finite state machine (FSM) or finite automaton is a model of behavior composed of states, transitions and actions.
Finite state machines are one type of the automata studied in automata theory and the theory of computation.
The machine can also be described as defining a language, in this case the language defined would contain every word accepted by the machine but none of the rejected ones.
en.wikipedia.org /wiki/Finite_state_machine   (1233 words)

  
 Mealy and Moore Finite State Machines - for ECE221
Both kinds of machines consist of flip-flop whose inputs are logical combinations of the input signals and the values of the flip-flop Q and Q' outputs.They differ in how the outputs of the machine are determined.
For a Mealy machine the outputs may depend on both the Q and Q' flip-flop outputs and the current inputs.
In the figure, we see that the output of a Moore machine is associated with the state itself, whereas with a Mealy machine the output is associated with both the state the machine is now in and the current values of the inputs.
www.ecs.umass.edu /ece/hill/ece221.dir/exFSM.html   (822 words)

  
 Chapter 8 Finite Automata with Output
We draw Moore machines in the same way as finite automata but the label in a state is composed both of the name of the state and the output character that the state produces.
Mealy machine are complete in the sense that there is a transition for each character in the input alphabet leaving every state.
We say that a Moore machine is equivalent to a Mealy machine if, given the same input, the output of the Moore machine after removing the first character is the same as the output of the Mealy machine.
www.mathsci.appstate.edu /~dap/classes/2490/chap8.html   (755 words)

  
 State machine models
Figure 2.30 shows a state diagram for the Mealy machine derived earlier which produces a 1 as output whenever the sequence 0101 is input.
Note that a state diagram for a Moore machine is labelled differently from a Mealy machine state diagram; the transitions are labelled only with the inputs which cause the transition, while the states are labelled with the corresponding outputs.
Comparing the Mealy and Moore state diagrams in Figures 2.30 and 2.31 respectively, it is clear that the diagrams are very similar for states A, B, C and D. State E is a ``new'' state, because the output of 1 must be associated with some state.
web.cs.mun.ca /~paul/cs3724/material/web/notes/node25.html   (1100 words)

  
 Sample Lab Write-up 2   (Site not responding. Last check: 2007-10-13)
A Mealy machine is similar to an NFA in the way that it is constructed.
However, a Mealy machine has some output based on the input instead of simply determining if the input is accepted by the machine.
This had the same number of lines of data as the first machine, since its domain of input was over {0,1}, and the output domain was the same as the previous example.
www.cs.pdx.edu /~janetv/CS250-02/samplelab2.html   (513 words)

  
 State diagram - Wikipedia, the free encyclopedia
For a deterministic finite state machine (DFA), nondeterministic finite state machine (NFA), generalized nondeterministic finite state machine (GNFA), or Moore machine, input is signified on each edge
For a Mealy machine, input and output are signified on each edge
With Harel statecharts it is possible to model "and" machines, where a machine is in two or more states at the same time.
en.wikipedia.org /wiki/State_diagram   (461 words)

  
 22C:122/55:132 Lecture 3, Spring 2001
Mealy was the first to clearly define this alternative, so we describe such machines as Mealy machines.
In the state diagram for a Mealy machine, each arc (state transition) is labeled with the input that enables that transition, a slash, and the output that is associated with that transition.
This requirement of a register to hold the current output is imposed on Mealy machines to prevent the output from changing except when the clock edge arrives indicating that the machine should advance to the next state.
www.cs.uiowa.edu /~jones/arch/spring01/notes/03.html   (1648 words)

  
 Registered Mealy State Machine   (Site not responding. Last check: 2007-10-13)
A "Mealy machine" is a finite state machine whose output is a function of state transition, i.e., a function of the machine's current state and current input.
There are many ways to implement such state machines in System Generator (e.g., using the MCode block to implement the transition function, and registers to implement state variables).
Of the four blocks in the state machine library, this is the fastest and most area efficient.
www.xilinx.com /products/software/sysgen/app_docs/user_guide_Chapter_10_Section_4_Subsection_12.htm   (571 words)

  
 [No title]   (Site not responding. Last check: 2007-10-13)
Mealy machine's output depends on both inputs and state variables.
This diagram is a Mealy machine, which means that the output is a function of the input while the machine is in a stable state.
In the case of describing a Moore machine it is be recommanded that we define the output process with a seperated PROCESS different from the state register PROCESS.
web.engr.oregonstate.edu /~sllu/vhdl/lec7.html   (1854 words)

  
 Lab 4   (Site not responding. Last check: 2007-10-13)
Both activities are related - the Mealy machine implementation is a better synchronized version (everything happens at the clock edge) where as for the Moore machine, the state transition happens at the change of input/present state conditions.
There are two parts on activities 5.1 and 5.2, and your objective is to design a Mealy machine and a Moore machine implementation of the elevator simulator.
Based on the diagrams in the manual, the Mealy machine has less states, and your task is to encode the state transitions, that is what happens when the outputs or the inputs change, and which state is next.
www.cse.psu.edu /~theochar/cg275/lab5.htm   (521 words)

  
 Finite State Machines with Output (Mealy and Moore Machines)   (Site not responding. Last check: 2007-10-13)
It means that given a Moore machine, you can create a Mealy machine, such that if both machines are fed the same sequence of inputs, they will both produce the same sequence of outputs.
However, the basic idea of converting a Mealy machine to a Moore machine is to increase the number of states.
Finite state machines are one way of describing the behavior of a circuit with state.
www.cs.umd.edu /class/spring2003/cmsc311/Notes/Seq/fsm.html   (2030 words)

  
 Mealy State Machine   (Site not responding. Last check: 2007-10-13)
This reference block provides a method for implementing a Mealy machine using block and distributed memory.
For example, a state machine with 8 states, 1 input, and 2 outputs that are registered can be realized with a single block RAM that runs at more than 150 MHz in a Xilinx Virtex device.
Then F(i,j) is the next state when the current state is i and the current input character is j, and O(i,j) is the corresponding output of the Mealy machine.
www.xilinx.com /products/software/sysgen/app_docs/user_guide_Chapter_10_Section_4_Subsection_9.htm   (533 words)

  
 [No title]
Fig 8.25b is a state diagram for the Mealy machine, with outputs associated with transition arcs rather than state bubbles.
Fig 8.33 is a mystery Mealy machine with one input X, and one output Z. Next state is a function of the current states, called A and B, and input X. Mealy state machine registers are created from one D and a M/S J-K flip-flop.
Fig 8.34 is a signal trace of the Mealy machine with input sequence 10101.
grail.cba.csuohio.edu /~jackie/eces281/ecs28113.txt   (1442 words)

  
 Homework due at 8 AM on Friday
That is, draw the state transition table and label all the rows and all the columns, but do not fill in any of the next-state/output areas.
Moore, because the output is a function only of the state of the machine.
Mealy machine because the output is a function both of the state of the machine and of the input
www.olemiss.edu /courses/EE/ELE_335/Fall2001/Fall2001HomeworkAnswers/1107hwa.htm   (122 words)

  
 Automata Definitions   (Site not responding. Last check: 2007-10-13)
The Turing machine restricted to a number of moves bounded by a fixed polynomial in n, p(n), where n = x, n is the length of the input string.
The machine must accept all strings in a language in polynomial time in order to be in P. P is a set of languages, also called a class of languages.
A Mealy machine is defined as M = (Q, sigma, Delta, delta, gamma, q0) using the definitions from the Moore machine with the exception that gamma maps Q cross Sigma to Delta.
cs.wwc.edu /~aabyan/CC2001/AL/automata_def.html   (1857 words)

  
 Mealy and Moore State Machines   (Site not responding. Last check: 2007-10-13)
Some machines have the rather convenient property that all the transitions entering a given state are assigned the same output value.
The difference between Mealy and Moore machines may at first appear to be minor, however there are significant differences between the design processes of each state machine.
When a beginning state is chosen in a Mealy machine, the output sequence is undefined until the first transition occurs, while, defining the initial state in a Moore machine determines directly the first symbol of the output sequence.
www.science.unitn.it /~flego/links/tesi1/node23.html   (242 words)

  
 Untitled Document   (Site not responding. Last check: 2007-10-13)
In case we are implementing a Mealy machine, the output is associated with the transitions as indicated on the following state diagram.
The functional simulation of the Mealy machine of the sequence detector is shown in Figure 6.
The functional simulation of the Moore machine together with the state diagram is shown in Figure 9.
cwx.prenhall.com /bookbind/pubbooks/xilinx/chapter6/medialib/foundation_stateeditor.html   (2310 words)

  
 Mealy and Moore
Mealy machines give you outputs instantly, that is immediately upon receiving input, but the output is not held after that clock cycle.
Mealy machine: machines having outputs associated with transition (input and the current state).
In Mealy as the output variable is a function both input and state, changes of state of the state variables will be delayed with respect to changes of signal level in the input variables, there are possibilities of glitches appearing in the output variables.
www.vlsibank.com /sessionspage.asp?titl_id=474   (560 words)

  
 Example of a Mealy Machine: string recognizer   (Site not responding. Last check: 2007-10-13)
Comparing this output with the one obtained for a Moore machine of the same sequence detector may let a casual observer think that there is a timing problem as the output seems to asserts already after the "101" input sequence.
On the other hand a Mealy machine can often be implemented with fewer states that a Moore machine as can be seen from the Moore example.
The implementation of the sequence detector as a synchronous Mealy machine is given in the next example.
www.seas.upenn.edu /ese/rca/software/abel/abel.ex1.html   (613 words)

  
 Vending/State Machine Project
In this program, the user will be able to follow how the machine is working on the inside by manipulating the normal inputs for this type of machine, nickels, dimes, and quarters.
From the state machine aspect, this program can deal with Moore machine and Mealy machine simultaneously, can let user change the view even in the middle of the operation.
In the Mealy state diagram, current state and all passed transitions are shown in red.
www.ece.gatech.edu /research/ccss/education/Java/1997.Summer/Projects/den_lia   (1449 words)

  
 State machine models
This model, shown pictorially in Figure 2.28 is called the Mealy model for sequential devices.
Note that state C was the only Mealy state in which the incoming arcs (or arrows) correspond to different outputs.
We can see that the Moore machine accepts the same input sequences as the Mealy machine we started with, and produces the same output sequence.
www.cs.mun.ca /~paul/cs3724/material/web/notes/node25.html   (1100 words)

  
 Example of a Mealy Machine: string recognizer   (Site not responding. Last check: 2007-10-13)
The machine will keep checking for the proper bit sequence and does not reset to the initial state after it has recognized the string.
Figure 1: State diagram, describing the sequence detector ("1011") implemented as a Mealy machine.
The difference with the regular Mealy machine, is that the output Z is now also clocked (see e.g.
www.seas.upenn.edu /ese/rca/software/abel/abel.ex3.html   (438 words)

  
 06.04.98 Registered-output FSMs synchronize outputs to state transitions
The only difference between these two types of machines is that the Mealy machine forms outputs derived from the inputs and the current state, and the Moore machine forms outputs derived from just the current state.
Next, turn your attention to the outputs, defined as the actions taken at each state, which are valid from the clock edge that gets the machine into the state until the clock edge that takes the machine to another state.
Because FSM registered outputs toggle at the same clock edge that transitions the machine into the associate state, analyzing the state-transition diagram is intuitive when relating it to FSM timing or sequencing during hardware debugging or simulation.
www.mrc.uidaho.edu /mrc/people/jff/digital/fsm_timing.html   (970 words)

  
 [No title]
The behavior of this machine is a Mealy behavior only when the machine is in state BB (and it's enough to make it a Mealy machine).
In the previous examples the outputs of the machine were not directly the outputs of the flip-flops.
Declaration of a mealy machine with no outputs is impossible because a mealy machine must have at least one output that depends on an input and not only on flip-flops.
www.armory.com /~rstevew/Public/EPROM/FiniteStateMachines/astater.txt   (2744 words)

  
 Finite State Machine Specification   (Site not responding. Last check: 2007-10-13)
The abstract state space of the Mealy machine contains lists of all states, the input alphabet, the output alphabet, and all transitions.
Checks are preformed to ensure that the machine is never in an invalid state.
All other information about the state such as the number of transitions from it is properties and the Mealy machine.
www.cs.virginia.edu /~drl7x/se2/statespec.html   (337 words)

  
 A MARBLE TOY   (Site not responding. Last check: 2007-10-13)
lever, and will leave the machine in a new state (which as stated above, is the combined position of all 3 levers).
  Mealy machines (Hopcroft and Ullman (1979, 42), Salomaa (1973, 31)) are finite-state machines that act as transducers or translators, taking on a string on an input alphabet and producing a string of equal length on an output alphabet.
Є Q is the initial state in which the machine is found before the first symbol of a string is processed.
www.oswego.edu /~jmurray/Website/MARBLE.htm   (779 words)

  
 Timing and Control Description
Most of the substantive portion of this is outlined on the attached finite state machine diagram that is attached.
Due to the large number of control signals that the state machine will generate, we have not included what all of them will be at every state in the state machine.
In a Mealy Machine implementation, it might be possible to reduce these 32 states down to 4.
www-ece.rice.edu /Courses/422/1995/GroupA/control.html   (1050 words)

  
 Mealy machines   (Site not responding. Last check: 2007-10-13)
Salomaa (1973, 31)) are finite-state machines that act as transducers or translators, taking a string on an input alphabet and producing a string of equal length on an output alphabet.
is the initial state in which the machine is found before the first symbol of a string is processed.
This machine, which may also be represented as in figure 2.2, outputs an
www.dlsi.ua.es /~mlf/nnafmc/pbook/node13.html   (115 words)

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