Magneto resistor sensor with diode short for a non-volatile random access ferromagnetic memory

Abstract

A non-volatile RAM device is disclosed which utilizes a plurality of ferromagnetic bits (,) each surrounded by a write coil (,) for directing the remnant polarity thereof is disclosed. The direction of magnetic remnance in each bit (,) is dictated by the direction of a current induced into write coil (,). Further, a magneto sensor (,) comprising a magneto resistor (,) coupled to a diode (,) is placed approximate each bit (,). The magneto resistor (,) is coupled to a sense line (,), and receives current at a first point of attachment, and returns current at a second point of attachment. The current passing across magneto resistor (,) is biased in a direction either right or left of the original current flow direction. If current is biased toward the anode end of diode (,) then it is complimentary to the preferred flow direction of diode (,), and flows easily there across. The ultimate effect is that the serial resistance of magneto resistor (,) is reduced, allowing a greater amount of current to pass into the sense line (,). When current is biased toward the cathode end of diode (,), then it is contrary to the preferred flow direction of the diode (,), and does not flow easily there across. The ultimate effect is that the serial resistance of magneto resistor (,) is increased, allowing a smaller amount of current to pass into sense line (,). The presence and amount of current found in the sense line (,) between the bit (,) and the detector (,) determines whether a digital value of “1” or “0” is stored in the magnetic bit (,). A method for storing binary data is also disclosed.