| This custom library addendum to gf180mcu_fd_io contains an overlay |
| pad for the bidirectional GPIO pad featuring an additional pin |
| with a connection directly to the pad on the near side of the 100 |
| ohm ESD resistor, making an analog connection to the pad through |
| a series 100 ohm resistor. |
| |
| There are three sets of pads in the PDK for 3, 4, and 5 layers of |
| metal, which correspond to open_pdks' gf180mcuA, B, and C/D, |
| respectively. The base cellname is the same in each case but the |
| LEF and GDS file names are given a suffix _3lm, _4lm, or _5lm. |
| Since the magic database file is always the same as the cell name, |
| the three versions have been placed in separate subdirectories. |
