The DDR3 / DDR4 library includes the combo driver/receiver cells with embedded power cells, the driver impedance calibration cell, and a full complement of support cells for both single-ended and differential signaling for DDR3 and DDR4 applications. Also included is a full complement of power, corner and spacer cells to assemble a complete pad ring by abutment. An included rail splitter allows multiple power domains to be isolated in the same pad ring while maintaining continuous VDD/VSS for robust ESD protection.