This directory contains standard format files for "sky130_ef_io",
which is an efabless addendum to the SkyWater I/O library "sky130_fd_io".

sky130_ef_io does the following:

(1) Changes the orientation of the corner pad from upper-right to
    lower-left with a wrapper cell called "sky130_fd_io__corner_pad".  Also
    extends the power buses to make the dimensions of the corner pad
    multiples of 1um.

(2) Adds a 1um-wide spacer cell to complement the existing 5um-wide
    spacer cell.

(3) Adds wrappers for all the combinations of power pad base cell +
    power pad overlay, to create all 12 combinations, for pads with
    either high- or low-voltage clamps, connecting to one of the six
    power domains vddio, vdda, vccd, vssio, vssa, or vssd.

(4) Fix a DRC error in the SkyWater GPIO pad layout

"sky130_ef_io" is open source copyright 2020 efabless, Inc.
Released under Apache 2.0 license