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Re: "Random" Circuit Needed.
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rickman
Apr 28, 2016, 12:44:29 PM4/28/16
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On 4/27/2016 4:35 PM, Jon Elson wrote:
> Tom Del Rosso wrote:
>
>
>>>
>>> I was puzzling over how to get 0000, but then it dawned... just use an
>>> 8-bit LFSR and use the last 4-bits.
> OK, you don't want to just use the last N bits of the LFSR, as they will
> shift over VERY predictably. So, if you want to use N bits, you need to
> allow the LFSR to advance N clocks and then latch the N parallel bits for
> use.
There is nothing that says an LFSR has to run at just one bit per clock
cycle. I have designed LFSR that run at 32 bits per clock cycle. It's
more logic, but sometimes you just have to have an all new number on
every clock.
BTW, you are an idiot for munging the "followup to" header.
--
Rick C
> Tom Del Rosso wrote:
>
>
>>>
>>> I was puzzling over how to get 0000, but then it dawned... just use an
>>> 8-bit LFSR and use the last 4-bits.
> OK, you don't want to just use the last N bits of the LFSR, as they will
> shift over VERY predictably. So, if you want to use N bits, you need to
> allow the LFSR to advance N clocks and then latch the N parallel bits for
> use.
There is nothing that says an LFSR has to run at just one bit per clock
cycle. I have designed LFSR that run at 32 bits per clock cycle. It's
more logic, but sometimes you just have to have an all new number on
every clock.
BTW, you are an idiot for munging the "followup to" header.
--
Rick C
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