Lpc2000

--- In lpc2000@yahoogroups.com, "Gus" <gus_is_working@y...> wrote:
> 
> Hello,
> 
> For the analog and audio smarts out there I have some questions.
> 
> I need to generate a good quality audio using LPC chips. The audio 
> will be a 44.1Khz 16-bit WAV file. I can take care of 
> loading/parsing data in RAM. Now, we need to convert the digital 
> data to analog signal.
> 
> - Would you use SPI or parallel bus to access the DAC chip?
> - What DAC chip you guys recomend?
> - What is the diference between codec and DAC?!?

Codec is short for coder/decoder which means ADC and DAC.  These days
you can get a sigma-delta stereo Codec for under $5.  So unless you
are really trying to cut every penny from your design, a CD quality
codec will be easy to work with.  Sigma delta is a way of using a very
high sample rate combined with a very simple circuit to produce an ADC
or DAC which samples the input at a very high rate and only needs a
very simple anti-alias filter.   

I don't know that they are typically SPI compatible since SPI is a
specific protocol.  Most of the codecs I have worked with are
compatible with the Sony/Philips serial interface, IIRC it is called
SPIF or SPDF or SPDI.   A google search should pull up some info.  The
bottom line is this is a simple interface which allows for up to 24
bits per sample and up to 48 kHz sample rate.  

Check out chips from Crystal, AKM and Philips.  I found a couple from
AKM which are very simple to use, low cost and very small.