A viable solution[Was]Re: MM5837?

[patchell]

    36 bits.....8 Mhz clock......Hmmm.. I get a repeat rate of 2 hours 22 minutes or so.  I
don't think you would hear that.  1 MHz clock would be 19 hours.....100KHz would be a week...

    Is that long enough for everybody?

Magnus Danielson wrote:

> From: patchell <patchell at silcom.com>
> Subject: A viable solution[Was]Re: MM5837?
> Date: Sun, 03 Sep 2000 13:31:59 -0700
>
> >     Here I am listening to my chugga chugga (I found it, didn't even have to do so by
> > inspection, I just listened to it, it is a whole lot worse than I remember), and a good
> > solution to this problem is staring me right in the face.
> >
> >     If you would all please turn to page 147 in the good book (Digikey-July-Sept 2000),
> > you will notice that the XC9536-15PC44C is only $3.30 in unit quantities.  It would be
> > entirely posible to put a 32 bit shift reg and XOR feedback into one of these little
> > suckers.  I just have to dig up the article I have stashed somewhere that shows which
> > cells to tap.  About a half hour at Xilinx Foundation, and I should have a hex file.
> > (Although, I will not be back at work until this Wedensday).  I would post the hex file
> > and schematic (and encourage others to post it on their site).
> >
> >     Anybody interested?
>
> Good idea. You should be able to get a 36 tap easy, just tap at 25 and you are
> home free. The XC9536 contains 36 macro-blocks and each of those contains an
> DFF.
>
> The good point about a loooooong sequence is that you can afford a higher
> clockrate without the risc of frequent looping. Also, as it has been pointed
> out before, you get a denser frequency spectrum so single frequencies does not
> stick out in narrow filters.
>
> Cheers,
> Magnus

--
 -Jim
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