Re: I need some consultancy from someone with ATAPI design expertise

From: Calin Dorohoi (calin_dorohoi_at_yahoo.com)
Date: 11/03/04 

Date: 3 Nov 2004 01:20:25 -0800

toby@telegraphics.com.au (Toby Thain) wrote in message news:<d6ce4a6c.0411021435.60dab37d@posting.google.com>...
> calin_dorohoi@yahoo.com (Calin Dorohoi) wrote in message news:<a1cf1181.0411020114.599c8a5c@posting.google.com>...
> > toby@telegraphics.com.au (Toby Thain) wrote in message news:<d6ce4a6c.0411011048.185e4dbb@posting.google.com>...
> > > seems to me
> > > you'd need a much faster MCU, or external RAM & DMA to handle realtime
> > > concurrent I/O and processing at 8X. (Doesn't matter for my
> > > application, which is non-realtime, PIO, and synchronous.)
> > >
> > > --Toby
> >
> > I don't like the idea of using DMA. I'd rather use a fast MCU. I'll
> > only need to read data at 1x, since the CD's will only be played back.
> > But if it's true that newer CD-ROM's can't read CD's at speeds below
> > 8X...
>
> I exaggerated a little. On further reflection, if all you're doing is
> spitting the data out again, the 40MHz PIC18 may manage 8X. Can you be
> more specific about what happens to the data?
> --T

The data will have to be played back. It will go to a DAC in I2S
format, that's all I have to do. The only problem is that I'll have to
send some data to a LCD display too, playback time, number of track,
exactly as in a CD-player.