What does my teacher want me to do?

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Discussion Overview

The discussion revolves around designing a sequential circuit to decode a specific serial sequence of bits (11011001) using a finite state machine (FSM). Participants explore the requirements and implications of the design, including input handling and state transitions.

Discussion Character

  • Technical explanation
  • Homework-related
  • Debate/contested

Main Points Raised

  • One participant asks whether the circuit can assume a "ready" state when receiving an 8-bit byte or if the sequence could be embedded within a continuous stream of bits.
  • Another participant suggests that the task involves designing a finite state machine (FSM) with one input and one output, triggered by the sequence over 8 clock cycles.
  • There is a clarification that FSMs require a clock input, which is acknowledged by another participant.
  • A participant reflects on previous experience with state machines that count without an input, questioning how to create an additional input for the sequence in this assignment.
  • One participant speculates that the design may require 5 flip-flops (FFs) and seeks confirmation or correction on this assumption.
  • A question is raised about the behavior of the LED after the sequence is detected, specifically whether it remains on.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and assumptions regarding the design requirements, with no consensus reached on specific methods or the handling of inputs. The discussion remains unresolved regarding the exact implementation details and the behavior of the LED.

Contextual Notes

There are uncertainties regarding the assumptions about the input state and the design methodology, as well as the potential use of different techniques beyond K-maps for deriving boolean equations.

david90
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Design a sequential circuit to decode a given serial sequence of bits. This is basically a state machine problem. When the given sequence occurs a LED is turned on. 11011001.

So there is an input to this problem?
 
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Don't know if I will be of any help on this. Are you allowed to assume that your circuit is always in some "ready" state (or whatever you call it) when it is fed an 8-bit byte? Or could those particular eight bits be buried anywhere within a continuing stream of bits, such that your circuit has to be ready to detect that pattern even when it is embedded in a bunch of other bits before and after it?
 
I'm assuming he's covered the design of finite state machines with you already? This is not a trivial sort of thing to solve, but it's straightforward once you know how. I believe he's telling you to design a finite state machine (either Mealy or Moore, as you choose, apparently) with one input and one output. When the input has followed 11011001 for 8 clock cycles, the state machine should be in a state where the output is asserted.

- Warren
 
Finite machine works with a clk input right?
 
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Yes, FSMs are sequential logic, and must have a clock.

- Warren
 
I've worked with state machine before that counts in a certain sequence but that doesn't have an input. You just turn on the clock and the circuit counts. The only input was the clk.

In this assigment in addition to the clk, I need to have another input to enter squence of numbers but how do I create this input??
 
nevermind about my last msg ^. I think I got it. So I guess it requires 5 FFs right? Correct me if I'm wrong please.

My teacher said that in the real world, they don't use K-maps to figure out the boolean equations; so what alternate method do they use? show me please
 
after the sequence is detected the LED remains on?
 
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The quarter is over. Final grades are in. Thanks for replying though. :)
 

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