The ONFI 4.0 library provides the combo driver / receiver cells, the ODT / driver impedance calibration cell, and the voltage reference cell to support both single-ended and differential ONFI 4.0 signaling. This library also meets the requirements for ONFI 3.0 and Toggle 2.0 signaling. The pad set includes a full complement of power, spacer, and adapter cells to assemble a complete pad ring by abutment. An included rail splitter allows isolated ONFI domains to be placed in the same pad ring with other power domains while maintaining continuous VDD/VSS in the pad ring for robust ESD protection.