[sdiy] super cheap synthisizers

[phillip m gallo]

Dallas makes the 89c420 who's instruction rate @33mhz is astounding (single
register add in 33ns). Since it has internal flash 16K which can run at this
execution rate, all of the I/O is available for implementation.  MIDI is a
simple and slow protocol well suited to interrupts.  I am early on in the
process implementing a similar channel voice using it.

regards,
p





-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of René Schmitz
Sent: Tuesday, June 11, 2002 8:11 AM
To: Ingo Debus; synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] super cheap synthisizers


At 15:53 11.06.02 +0200, Ingo Debus wrote:
>Ugh. Are AVRs really that fast?

CPI (cycles per instruction) is nearly one. They are faster than
the 8051 or the PICs (at least those I'm familiar with, which have
four clock cycles per instruction.)

>Can it still process incoming MIDI now and then?

If the timer ran slow enough (1Mhz is probably too fast), and the
timer routine being short there would be enough cycles left to run
a main routine that would process the UART bytes.

>Using a 12 Mhz 8051 clone (shortest instruction execution time 1
>microsecond) right now I'm not even dreaming of that speed. But then
>it's fast enough for my purpose.

The AVR would deliver the same speed at 1Mhz.

Cheers,
 René
--
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159



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