Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!brutus.cs.uiuc.edu!psuvax1!rutgers!ucsd!anise.acc.com!ivucsb!todd
From: todd@ivucsb.sba.ca.us (Todd Day)
Newsgroups: comp.dsp
Subject: Re: More digital mixer stuff
Message-ID: <1989Sep29.102204.8798@ivucsb.sba.ca.us>
Date: 29 Sep 89 10:22:04 GMT
References: <9238@pyr.gatech.EDU>
Organization: Disillusioned Graduate Hackers, Santa Barbara, CA
Lines: 36

byron@pyr.gatech.EDU (Byron A Jeff) writes:

~Even if it were serial I'd probably just shift it into shift registers
~and read in the parallel outputs when all of the bits of a complete
~sample has been shifted in.

What I was refering to was the *built-in* serial shift registers in
the DSP chips.  That way, you wouldn't need the glue logic.

~>Remember that since you are using an analog MUX, the samples can't all
~>be done at EXACTLY the same time, so there will be a slight delay between
~>all of the channels.
~I'm brand new in this domain. I have no clue what the effect of the
~delay between channels will be. Can you give me an idea?

Ch 1 - delay - Ch 2 - delay - Ch 3 - delay - Ch 4

The delay will be the length of time it takes to switch from one
channel to the next via the MUX and then sample with the sample/hold.
Probably not very signifigant, but those who spend $1000 on interconnects
for their stereo systems would probably complain.  Of course, they wouldn't
be listening to digital, anyway, would they? :-)

~Another reponse I saw indicates that a 56001 wouldn't be able to handle
~mixing 8 channels much less doing any kind of EQ, reverb, etc. He
~suggested a DSP for each channel.

I know that one chip can *at least* emulate a 2 channel 10 band 12 dB
equalizer from a Motorola app note.  I wouldn't think that reverb would be
that tough to do.

-- 

Todd Day  |  todd@ivucsb.sba.ca.us  |  ivucsb!todd@anise.acc.com
"Ya know, some day these scientists are going to invent something
	that can outsmart a rabbit" -- Bugs Bunny