A nonvolatile magnetic flip-flop (MFF) primitive cell for SoC design libraries has been developed using a unique MRAM process. It has high design compatibility with conventional CMOS LSI designs. MFF maximum frequency was estimated to be 3.5 GHz, which is comparable to that of a normal CMOS DFF. An MFF test chip was fabricated with the process. The chippsilas functional performance was sufficiently high to demonstrate the potential of MFFs, which helps to reduce the power dissipation of SoCs dramatically.