This silicon-proven, I/O Library features a 5V General Purpose I/O, 5V Open-Drain I/O, 5V Analog I/O, 5V Power Supply and an area efficient 5V ESD protection scheme. The functional cells in the library (GPIO & ODIO) feature an Output Enable pin which, when de-asserted, place the I/O in a HiZ state, and can control multiple modes of output operation with the Output Mode Control pins. The input RX path for this library all have selectable operations between a Schmitt trigger input with hysteresis, a standard buffer with no hysteresis, and a low input voltage mode that can receive a voltage level much lower than the I/O supply without causing metastability or large leakage current. The library has no poly orientation limitations and can be used in any orientation. The library cells are only built up to metal three, but include an metal 4 pad anchor that can be overlaid with either a wirebond or connected to a BUMP. ESD design level are 2kV HBM, 500V CDM and +/-125mA Latch-up.