sky130_fd_io: Initial documentation only release.

The SKY130 IO cells is a toolkit IP. It contains all the cells and
primitives required to construct an I/O ring in the SKY130 technology.

This sky130_fd_io library contained in this document covers different
kinds of I/O cells,

 * a general purpose I/O (`sky130_fd_io__gpio`), and
 * a special I/O (`sky130_fd_io__sio`),
 * a reference generator (`sky130_fd_io__refgen`) for providing voltage
   references to the `sky130_fd_io__sio`, and
 * Power and Ground (PG) cells that make up the I/O ring.

Signed-off-by: Tim 'mithro' Ansell <me@mith.ro>

docs/conf.py

@@ -309,6 +309,8 @@ epub_title = project
 # A list of files that should not be packed into the epub file.
 epub_exclude_files = ['search.html']
 
+# Enable the figures and numbers
+numfig = True
 
 # -- Extension configuration -------------------------------------------------
 

docs/contents/libraries.rst

@@ -70,7 +70,6 @@ Third party developers are encourage to create new and interesting libraries for
 
     libraries/sky130_fd_pr_*/README
 
-
 .. _sky130-lib-standardcells:
 
 :lib_type:`Digital Standard Cell` Libraries

docs/contents/libraries/sky130_fd_io

@@ -0,0 +1 @@
+../../../libraries/sky130_fd_io/latest

docs/contents/libraries/sky130_fd_pr

@@ -0,0 +1 @@
+../../../libraries/sky130_fd_pr/latest

libraries/sky130_fd_io/latest/README.rst

@@ -0,0 +1,10 @@
+:lib:`sky130_fd_io` - SKY130 IO and periphery cells (SkyWater Provided)
+=======================================================================
+
+Initial documentation only release.
+
+.. toctree::
+    :maxdepth: 1
+    :name: sky130-lib-foundry-io-top
+
+    docs/user_guide