PIC power?

Paul Maddox Paul.Maddox at unilever.com
Mon Nov 22 09:59:37 CET 1999


Ingo,

  I agree, I would use one chunk of SRAM (say 256Kbyte)
clear the ram to start with.. then do this,

1) Read Ram, put Data in DAC
2) Read ADC and put data into Ram
3) Increment Ram counter
4) delay
5) goto 1

  By varying the delay you could vary the speed of the delay,
now ok this isnt a great solution for long delays, but at a sample
rate of 64K, you could have 4 seconds of delay with 256K of
SRAM.. with an AVR running at 8Mhz (125nS per instruction)
you could easily do this, maybe have some spare time to 
do something funky with the data in the sram.

  Paul

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-----Original Message-----
From:	Ingo Debus [SMTP:debus at cityweb.de]
Sent:	Saturday, November 20, 1999 10:03 AM
To:	synth-diy at mailhost.bpa.nl
Subject:	Re: PIC power?



The Old Crow wrote:
> A delay line with 1ms accuracy to, say, 512ms would need to
> block move 512 bytes in a RAM device in under 1ms, but as a 20MHz PIC
> executes 200ns instructions, this is not a problem.

I don't understand a word #-). Why 512 bytes in 1ms?

Why do you need block moves at all for a delay? Can't you use a circular buffer
with moving read and write pointers?

Ingo






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