userx2
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Hello folks
I have to try and correct someone else's poor design here on a something.
This has a Lattice M4A5 PLD.
This design is basically a address decoder and it also contains 2 enable lathes. It has no clock.
It has a read and a write line going into it and a reset line driven from an RC reset circuit.
The 2 latches get set once a write to a certain address occurs. They can not be reset unless an external reset occurs.
They are used to keep an external circuit disabled until the host cpu has booted up and enables the latches.
The problem is that external factors cause spikes on the reset input of this design and this in turn resets the internal latches, disabling vital external circuitry.
So I had the brilliant idea that I can disbale the reset (internally in the PLD) after it has occured once after power up.
So far, I have not been able to come up with a solution since I cannot think of anything I can use a deciding factor to disable the reset.
The code is written in AbelHDL.
Perhaps someone else has an opinion on how this can be done or if it can even be done within the constraints of no clock etc.
Best regards
X
I have to try and correct someone else's poor design here on a something.
This has a Lattice M4A5 PLD.
This design is basically a address decoder and it also contains 2 enable lathes. It has no clock.
It has a read and a write line going into it and a reset line driven from an RC reset circuit.
The 2 latches get set once a write to a certain address occurs. They can not be reset unless an external reset occurs.
They are used to keep an external circuit disabled until the host cpu has booted up and enables the latches.
The problem is that external factors cause spikes on the reset input of this design and this in turn resets the internal latches, disabling vital external circuitry.
So I had the brilliant idea that I can disbale the reset (internally in the PLD) after it has occured once after power up.
So far, I have not been able to come up with a solution since I cannot think of anything I can use a deciding factor to disable the reset.
The code is written in AbelHDL.
Perhaps someone else has an opinion on how this can be done or if it can even be done within the constraints of no clock etc.
Best regards
X