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Altera_Forum's avatar
Altera_Forum
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10 years ago

Quartus II, FSM, Vector waveform file not giving correct output

Hi there, this is my first post so i'm quite new to this forum.

I have designed a circuit that should give me an output of 1 when it detects an input of 101. For some reason it doesn't seem to be doing that. Can someone tell me why this might be? I have simulated the circuit and there seems to be no problem there. I have attachedd the block diagram file and the vector waveform file.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    Some additional information. The circuit is operating as intended but the output will never go high due to the correct input never being reached. Can someone please tell me how do i feed the system the correct input? Does all the input need to occur in 1 clock period?

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    If the input is asynchronous, then you will probably be violating the setup time on the registers, causing them to go meta-stable. You need to double register the input to ensure you avoid meta-stable inputs.