This is a "light-weight" version of the IIC-JKU audiodac.  The full
version is a Caravel user project and the Efabless fork of it can
be found at https://github.com/efabless/sky130_iic_ip__audiodac_v1/.
When used as a dependency for another project, the "caravel"
dependency used by the user project wrapper becomes problematic
for setting up the git submodules.  So this version strips the
"caravel" submodule and all references to the user project wrapper.
Note that the digital controller has also been removed, except for
the verilog RTL, from which it can be regenerated if needed.
The primary use of this "lite" version is for the Frigate harness
chip analog subsystem, and the audiodac digital driver has been
incorporated into the Frigate SoC.  Only the output driver is used
by the Frigate analog subsystem.  Also:  Note that the "lite"
version of the layout is used in Frigate, as the output is passed
through switches to the analog pads, and the original version has
too much drive strength.  This reduction in output drive strength
is a consequence of the Frigate analog switch matrix architecture.

This repository may be further refined in the future by putting
back the synthesized digital controller layout;  however, it is
not the immediate goal of the Frigate harness chip design.

Thanks to Harald Pretl and his group at Johannes Kepler University
for the open-source design.