Mealy and Moore Machines

Introduction

• Discussion on the difference between Mealy and Moore machines.
• Importance of understanding for college/university level exams.

Definitions

• Mealy Machine: Output depends on current state and current input.
• Moore Machine: Output depends only on the current state, independent of input.

Transition Tables

• Transition tables define outputs for both Mealy and Moore machines.
• Examples were provided to illustrate differences in outputs based on input and current state.

Example of Mealy Machine

• To check the remainder of a binary string divided by 3.
• Example output behavior based on current state and input:
  • If in state Q0 with input 0, output is 1.
  • If in state Q0 with input 1, output is 0.

Example of Moore Machine

• For Moore machine, output is defined consistently based on states:
  • For example, state Q0 outputs 0 regardless of input.
  • Outputs are defined for each state independently of inputs.

Key Differences

• Output Function:
  • Mealy: Output function depends on both state and input.
  • Moore: Output function depends solely on the state.
• Synchronous vs Asynchronous:
  • Mealy machines can be faster due to asynchronous output.

Clock Pulses

• Mealy machines use clock pulses to trigger outputs, generating outputs faster.
• Moore machines have outputs that are synchronous with the clock.

Conversion

• Discussed the conversion between Mealy and Moore machines.
• Noted that the number of states may change during conversion.

Conclusion

• Review of major differences and concepts surrounding Mealy and Moore machines.