Claims
- 1. A magneto-resistive storage element comprising:
a magneto-resistive bit having a first end and a second end; a word line extending adjacent the magneto-resistive bit, the word line connected to the first end of the magneto-resistive bit; and switching means coupled to the second end of the magneto-resistive bit for selectively providing a path for a sense current to flow from the word line, through at least part of the magneto-resistive bit, and to a predetermined voltage terminal.
- 2. A magneto-resistive storage element according to claim 1, wherein the switching means comprises a transistor.
- 3. A magneto-resistive storage element according to claim 1, wherein the predetermined voltage terminal is coupled to ground.
- 4. A magneto-resistive storage element according to claim 1, wherein the magneto-resistive bit is an elongated magneto-resistive bit having a length and a width.
- 5. A magneto-resistive storage element according to claim 4, wherein the word line is configured to carry a word line current that produces a word line magnetic field component that extends along the length of the elongated magneto-resistive bit.
- 6. A magneto-resistive storage element according to claim 5, wherein the sense current produces a write sense magnetic field component that extends along the width of the elongated magneto-resistive bit.
- 7. A magneto-resistive storage element according to claim 1, wherein the word line is a metal word line that extends above or below the magneto-resistive bit.
- 8. A magneto-resistive storage element according to claim 7, further comprising connecting means for connecting the metal word line to the first end of the magneto-resistive bit, the connecting means including a via or contact structure.
- 9. A magneto-resistive storage element according to claim 1, wherein the switching means has at least two resistive modes, including:
an intermediate resistive mode for providing a path for a write sense current to flow from the word line; and a lower resistive mode for providing a path for a read sense current to flow from the word line.
- 10. A magneto-resistive storage element according to claim 9, wherein the switching means further includes a higher resistive mode for substantially preventing the write sense current and the read sense current from flowing from the word line.
- 11. A method for writing a magneto-resistive bit, the method comprising the steps of:
supplying a word line current adjacent the magneto-resistive bit; and drawing a sense current from the word line current through at least part of the magneto-resistive bit.
- 12. A method according to claim 11, wherein the magneto-resistive bit has a word line extending adjacent thereto, and wherein the word line current produces a word line magnetic field component that extends in a first direction relative to the magneto-resistive bit.
- 13. A method according to claim 12, wherein the sense current produces a sense line magnetic field component that extends in a second direction relative to the magneto-resistive bit, wherein the first direction is orthogonal to the second direction.
- 14. A method according to claim 13, wherein the drawing step draws a sufficient sense current to write the magneto-resistive bit.
- 15. A magneto-resistive storage device comprising:
a magneto-resistive bit having a first end and a second end; a word line extending adjacent the magneto-resistive bit, the word line connected to the first end of the magneto-resistive bit; word line current providing means for selectively providing a word line current to the word line; switching means coupled to the second end of the magneto-resistive bit for selectively providing a path for a read or a write sense current to flow from the word line, through at least part of the magneto-resistive bit, and to a predetermined voltage terminal; reading means coupled to the word line for providing a path for the read sense current to flow to the word line, the reading means reading the resistive state of the magneto-resistive bit via the read sense current; and controller means for controlling the word line current providing means, the switching means, and the reading means; the controller means performing a write of the magneto-resistive bit by enabling the word line current providing means to provide a word line current to the word line, enabling the switching means to provide a path for the write sense current to flow from the word line, through at least part of the magneto-resistive bit, and to the predetermined voltage terminal, and disabling the reading means to prevent the reading means from providing a path for the read sense current to flow to the word line; and the controller means performing a read of the magneto-resistive bit by disabling the word line current providing means to prevent the word line current providing means from providing a word line current to the word line, enabling the switching means to provide a path for the read sense current to flow from the word line, through at least part of the magneto-resistive bit, and to the predetermined voltage terminal, and enabling the reading means to provide a path for the read sense current to flow to the word line and to read the resistive state of the magneto-resistive bit via the read sense current.
- 16. A magneto-resistive storage device according to claim 15, wherein the switching means has at least two resistive modes, including:
an intermediate resistive mode for providing a path for the write sense current to flow from the word line, through at least part of the magneto-resistive bit, and to the predetermined voltage terminal; and a lower resistive mode for providing a path for the read sense current to flow from the word line, through at least part of the magneto-resistive bit, and to the predetermined voltage terminal.
- 17. A magneto-resistive storage device according to claim 16, wherein the switching means further includes a higher resistive mode for substantially preventing the write sense current and the read sense current from flowing from the word line.
- 18. A magneto-resistive storage device according to claim 17, wherein the switching means comprises a transistor.
- 19. A magneto-resistive storage element according to claim 18, wherein the predetermined voltage terminal is coupled to ground.
- 20. A method for operating a magneto-resistive storage device, the magneto-resistive storage device having a magneto-resistive bit with a first end and a second end, a word line extending adjacent the magneto-resistive bit with the word line connected to the first end of the magneto-resistive bit, and a reading circuit coupled to the word line for providing a path for a read sense current to flow to the word line and for sensing the resistive state of the magneto-resistive bit via the read sense current, the method comprising the steps of:
preventing the read circuit from providing a path for the read sense current to flow to the word line; supplying a word line current to the word line; and drawing a write sense current from the word line current through at least part of the magneto-resistive bit.
- 21. A method according to claim 20, further comprising the steps of:
preventing the word line current from being supplied to the word line; allowing the read circuit to provide a path for the read sense current to flow to the word line; drawing a read sense current from the word line through at least part of the magneto-resistive bit; and sensing the resistive state of the magneto-resistive bit using the read sense current.
- 22. A method according to claim 21, further comprising the step of storing the resistive state of the magneto-resistive bit in a storage element.
- 23. A magneto-resistive storage element comprising:
a first magneto-resistive bit having a first end and a second end; a second magneto-resistive bit having a first end and a second end; a word line extending adjacent the first and second magneto-resistive bits such that a word line current passing through the word line provides a magnetic field component toward one end of the first magneto-resistive bit and toward the other end of the second magneto-resistive bit, the word line connected to the first end of the first magneto-resistive bit and the first end of the second magneto-resistive bit; and switching means coupled to the second end of the first magneto-resistive bit and the second end of the second magneto-resistive bit for selectively providing a path for a write sense current to flow from the word line, through at least part of the first and second magneto-resistive bits, and to a predetermined voltage terminal.
- 24. A magneto-resistive storage element according to claim 23, wherein the switching means has at least two resistive modes, including:
an intermediate resistive mode for providing a path for the write sense current to flow from the word line, through at least part of the first and second magneto-resistive bits, and to the predetermined voltage terminal; and a lower resistive mode for providing a path for a read sense current to flow from the word line, through at least part of the first and second magneto-resistive bits, and to the predetermined voltage terminal.
- 25. A magneto-resistive storage element according to claim 24, wherein the switching means further includes a higher resistive mode for substantially preventing the write sense current and the read sense current from flowing from the word line, through at least part of the first and second magneto-resistive bits, and to the predetermined voltage terminal.
- 26. A magneto-resistive storage element according to claim 23, wherein the switching means comprises a transistor having a source, a drain and a gate, the drain of the transistor being coupled to the second end of the first magneto-resistive bit and the second end of the second magneto-resistive bit, the source of the transistor being coupled to the predetermined voltage terminal, and the gate of the transistor being coupled to a control terminal.
- 27. A magneto-resistive storage element according to claim 23, wherein the switching means comprises a first transistor and a second transistor each having a source, a drain and a gate, the drain of the first transistor being coupled to the second end of the first magneto-resistive bit, the drain of the second transistor being coupled to the second end of the second magneto-resistive bit, the source of the first transistor and the source of the second transistor being coupled to the predetermined voltage terminal, and the gate of the first transistor and the gate of the second transistor being coupled to a control terminal.
- 28. A magneto-resistive memory comprising:
a latch circuit including a first inverter and a second inverter coupled together in a cross-coupled configuration, each of the first and second inverters having a positive supply terminal, a negative supply terminal, an input terminal and an output terminal, the positive supply terminal of the first and second inverters coupled to a power supply voltage; the latch circuit further including a load transistor for loading a state into the latch circuit, the load transistor having a source terminal coupled to the input terminal of the first inverter, a drain terminal coupled to the input terminal of the second inverter, and a gate terminal; at least one magneto-resistive memory cell having a first magneto-resistive bit with a first end and a second end, and a second magneto-resistive bit having a first end and a second end, the second end of the first magneto-resistive bit and the second end of the second magneto-resistive bit being selectively coupled to ground through one or more switching means; a first word line coupled to the negative supply terminal of the first inverter and extending adjacent the first magneto-resistive bit of at least one magneto-resistive memory cell, each of the first magneto-resistive bits having a first end coupled to the first word line; a second word line coupled to the negative supply terminal of the second inverter and extending adjacent the second magneto-resistive bit of at least one magneto-resistive memory cell, each of the second magneto-resistive bits having a first end coupled to the second word line; and a write transistor having a source terminal coupled to the first word line, a drain coupled to the second word line, and a gate coupled to a write control terminal, the write transistor for selectively connecting the first word line and the second word line depending on the state of the write control terminal.
- 29. A magneto-resistive memory according to claim 28, wherein the one or more switching means include a transistor.
- 30. A magneto-resistive memory according to claim 29, further comprising a word line current generator for selectively providing a word line current through the first word line, the write transistor and the second word line.
CROSS-REFERENCE TO RELATED CO-PENDING APPLICATIONS
[0001] This Application is related to co-pending U.S. patent application Ser. No. 09/059,871 filed Apr. 14, 1998, and entitled “NON-VOLATILE STORAGE LATCH”, U.S. patent application Ser. No. 09/396,189, filed Sep. 14, 1999, and entitled “NON-VOLATILE STORAGE LATCH”, and U.S. patent application Ser. No. 1016.1118101,filed ______, and entitled “NON-VOLATILE STORAGE LATCH”, all of which are incorporated herein by reference.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09638637 |
Aug 2000 |
US |
Child |
10174214 |
Jun 2002 |
US |