audio chip

[stevens@watson.ibm.com (Andrew Stevens)]

OK, I have received complete data from Crystal Semiconductor on the
CS4248 audio codec in the TP750.  It is one of their standard
off-the-shelf parts.  Here is the general description of the part:

"The CS4248 is a mixed signal integrated circuit that provides 16-bit
audio for computer multimedia systems.  The CS4248 includes stereo
audio converters and complete on-chip filtering for record and
playback of 16-bit audio data.  The CS4248 combines conversion, analog
mixing, and programmable gain and attenuation to provide a complete
audio subsystem in a single 68-pin PLCC or 100-pin TQFP package.  The
CS4248 includes an 8-bit parallel interface to the industry standard
ISA bus."

A complete register mapping is included in the data.  There are also
device drivers available for Windows 3.1 and NT, as well as diagnostic
software.  The Monologue software is also available in the Crystal
data book (apparently it was a joint development by Crystal and First
Source).

The CS4248 is functionally equivalent to the Analog Devices AD1848
rev. K chip.

The phone number for Crystal Semiconductor (Austin, TX) is (512) 445-7222.

--andy