Resistive memory device, resistive memory system, and method of operating resistive memory device
A method of operating a resistive memory device having a plurality of word lines and a plurality of bit lines includes selecting one or more first memory cells connected to a first bit line, selecting one or more second memory cells connected to a second bit line, and simultaneously performing a reset write operation on the first and second memory cells using a first write driver.
1. A method of operating a resistive memory device that includes a plurality of word lines and a plurality of bit lines, the method comprising:
selecting one or more first memory cells connected to a first bit line;
selecting one or more second memory cells connected to a second bit line;
simultaneously performing a reset write operation on the first and second memory cells using a first write driver;
after performing the reset write operation, selecting two or more first memory cells connected to the first bit line;
reading the two or more first memory cells and providing a plurality of read results to a first sense amplifier; and
simultaneously verifying the first memory cells by using the first sense amplifier, wherein:
memory cells arranged in regions where two or more word lines and a first bit line intersect are selected, and
the read currents from the selected memory cells are provided to the first sense amplifier through the first bit line.
2. The method of claim 1 , further comprising:
receiving an erase command indicating an erase request, wherein
the reset write operation is simultaneously performed on the first and second memory cells, in response to the erase command.
3. The method of claim 1 , further comprising:
receiving a write command indicating a data write request, wherein
the reset write operation is simultaneously performed on the first and second memory cells, in response to the write command.
4. The method of claim 3 , further comprising, after the simultaneous reset write operation is performed, performing a write operation using write data accompanying the write command.
5. The method of claim 1 , wherein:
the bit lines comprise 2*N-number of bit lines and N-number of write drivers are commonly connected to two bit lines and arranged corresponding to the 2*N-number of bit lines, wherein N is an integer greater than or equal to 1, and
as all bit lines are simultaneously selected, all memory cells connected to one or more word lines are simultaneously reset-written.
6. The method of claim 1 , wherein the reset write operation further comprises:
simultaneously selecting at least two word lines, wherein
the first write driver simultaneously performs the reset write operation on two or more first memory cells connected to the first bit line and two or more second memory cells connected to the second bit line.
7. The method of claim 1 , further comprising:
selecting one or more third memory cells connected to at least one of third to n-th bit lines of the plurality of bit lines, wherein
the first write driver simultaneously performs the reset write operation on the first to third memory cells.
8. The method of claim 1 , wherein:
the resistive memory device comprises first and second layers, and
the first bit line is arranged on the first layer and the second bit line is arranged on the second layer.
9. The method of claim 1 , further comprising:
after performing the reset write operation, reading the first and second memory cells and providing a plurality of results from reading the first and second memory cells to the first sense amplifier; and
simultaneously verifying the first and second memory cells by using the first sense amplifier.
10. The method of claim 9 , wherein a current flowing through the first memory cells and a current flowing through the second memory cells are summed and provided to the first sense amplifier.
11. The method of claim 9 , wherein:
at least two word lines are simultaneously selected, and
the first sense amplifier simultaneously performs a verify operation on the two or more first memory cells connected to the first bit line and two or more second memory cells connected to the second bit line.
12. The method of claim 1 , wherein:
the resistive memory device stores information related to a selection of memory cells on which a previous reset write operation was simultaneously performed, and
the method further comprises referring to the information to select the memory cells on which the reset write operation is simultaneously performed.
13. A method of operating a resistive memory device that includes a plurality of word lines and a plurality of bit lines, the method comprising:
selecting two or more memory cells connected to one or more word lines or one or more bit lines;
providing a signal obtained by summing read currents from the selected memory cells to a first sense amplifier; and
generating a verify result by simultaneously verifying the selected two or more memory cells through the first sense amplifier, wherein:
memory cells arranged in regions where two or more word lines and a first bit line intersect are selected, and
the read currents from the selected memory cells are provided to the first sense amplifier through the first bit line.
14. The method of claim 13 , wherein the generating of the verify result determines a pass or fail according to a result of comparing the signal obtained by summing the read currents with a reference current.
15. The method of claim 13 , wherein:
a second bit line also intersects the two or more word lines in the regions where the selected memory cells are arranged, and
the read currents from the selected memory cells are provided to the first sense amplifier through the first and second bit lines.
16. The method of claim 13 , wherein:
the resistive memory device comprises first and second layers,
the first sense amplifier receives the read currents through the first bit line and a second bit line, and
the first bit line is arranged on the first layer and the second bit line is arranged on the second layer.
17. A method of operating a resistive memory device that includes a plurality of word lines and a plurality of bit lines, the method comprising:
selecting one or more first memory cells connected to a first bit line;
selecting one or more second memory cells connected to a second bit line; and
simultaneously performing a reset write operation on the first and second memory cells using a first write driver, wherein:
the resistive memory device stores information related to a selection of memory cells on which a previous reset write operation was simultaneously performed, and
the method further comprises referring to the information to select the memory cells on which the reset write operation is simultaneously performed.