Resistive cross point memory
AssigneeHewlett-Packard Development Company, L.P.
InventorsFrederick A. Perner, Kenneth Kay Smith
Life of this patent
Estimating the term…
Abstract
Embodiments of the present invention provide a resistive cross point memory. The resistive cross point memory comprises an array of memory cells and a read circuit. The read circuit is configured to sense a resistance through a memory cell in the array of memory cells to obtain a sense result and calibrate the read circuit based on the sensed result. The read circuit comprises an up/down counter that provides a calibration value to the read circuit.
Claims25
A resistive cross point memory, comprising:
- an array of memory cells;
- and
- a read circuit comprising a charge amplifier and configured to sense a resistance through a memory cell in the array of memory cells to obtain a sense result and adjust the read circuit based on the sensed result, where the road circuit comprises an up/down counter that provides a calibration value to the charge amplifier and the read circuit provides calibration for adjusting a coarse calibration value and a fine calibration value.
A resistive cross point memory, comprising:
- an array of memory cells;
- and
- a read circuit configured to sense a resistance through a memory cell in the array of memory cells to obtain a sense result and adjust the read circuit based on the sensed result, where the read circuit comprises an up/down counter that provides a calibration value to the read circuit, where the up/down counter receives a clock pulse to adjust a fine calibration value in a tune-up calibration.
A magnetic memory comprising:
- a memory cell;
- a charge amplifier configured to provide a sense voltage to the memory cell and integrate a sense current through the memory cell;
- a sense amplifier configured to sense integration time and provide a sense result and including a counter that provides the sense result as a sense count;
- and
- an up/down counter configured to provide a calibration value to the charge amplifier.
A magnetic memory, comprising:
- means for sensing a resistance through a memory cell;
- means for comparing the sensed resistance to a threshold value;
- means for modifying a count in an up/down counter that provides a calibration value to calibrate a read circuit to improve reliability of read operations
- means for coarse calibration of the read circuit;
- and
- means for fine calibration of the read circuit.
A method of calibrating a magnetic memory, comprising:
- sensing a resistance through a memory cell to obtain a sense result;
- comparing the sense result to threshold values to determine complete calibration regions, tune-up calibration regions, and no calibration regions;
- and
- clocking an up/down counter to adjust a calibration value.
A method for calibrating a read circuit in a resistive cross point memory comprising:
- providing an up/down counter;
- selecting a resistive cross point memory cell;
- sensing resistance through the selected resistive cross point memory cell in a sense operation;
- obtaining a sense result that represents an integration time for the sense operation;
- comparing the sense result to a threshold value;
- and
- applying a clock signal to the up/down counter to adjust fine and coarse calibration values in the event the sense result exceeds the threshold value.
A method comprising:
- calibrating a read circuit in a magnetic memory to improve read operations of the read circuit by:
- performing a first sense operation and obtaining a first sense result;
- comparing the first sense result to first and second upper threshold values and to first and second lower threshold values, where the first upper threshold value is greater than the second upper threshold value and the first lower threshold value is less than the second lower threshold value;
- providing a clock pulse to an up/down counter if the first sense result is one of the following:
- greater than the second upper threshold value and less than the second lower threshold value;
- performing a second sense operation and obtaining a second sense result if the first sense result is one of the following:
- greater than the first upper threshold value and less than the first lower threshold value;
- and
- comparing the second sense result to the first and second upper threshold values and to the first and second lower threshold values.
Dependencies are inferred from the claim text.