A memory unit includes a giant magnetoresistance cell electrically coupled between a write bit line and a write source line and a magnetic tunnel junction data cell electrically coupled between a read bit line and a read source line. A write current passing through the giant magnetoresistance cell switches the giant magnetoresistance cell between a high resistance state and a low resistance state. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by magnetostatic coupling with the giant magnetoresistance cell. The magnetic tunnel junction data cell is read by a read current passing though the magnetic tunnel junction data cell.