Multi-state resistance changing memory with a word line driver for applying a same program voltage to the word line
A resistance changing memory unit cell includes a current control component operably coupled to a bit sense line, and a resistance changing memory element coupled between the current control component and a word line.
1. A resistance changing memory unit cell, comprising:
a current control component operably coupled to a sense bit line;
a resistance changing memory element coupled between the current control component and a word line; and
a word line driver coupled to the word line and configured to facilitate writing of different data states to the unit cell by delivering the same program voltage to the word line for different program states during a program mode, and delivering an erase voltage during an erase mode, wherein the program voltage and the erase voltage are different.
2. The unit cell of claim 1 , wherein the current control component comprises a control terminal configured to receive a plurality of different control signals, and provide a current limiting function comprising a plurality of differing current levels greater than two in response thereto.
3. The unit cell of claim 1 , wherein the resistance changing memory element comprises a metal-insulator-metal memory element.
4. The unit cell of claim 3 , wherein the metal-insulator-metal memory element comprises a binary oxide.
5. The unit cell of claim 1 , wherein the current control component comprises a transistor.
6. A resistance changing memory, comprising:
a current control component coupled to a sense bit line;
a resistance changing memory element coupled between the current control component and a word line;
a read sense circuit coupled to the sense bit line, and configured to determine a state of the resistance changing memory element; and
a word line driver circuit coupled to the word line, and configured to selectively provide a non-zero read voltage or a write voltage on the word line based on a read operation or a write operation, respectively, wherein the write voltage comprises the same program voltage for different program states during a program mode, and an erase voltage during an erase mode, wherein the program voltage and the erase voltage are different.
7. The memory of claim 6 , further comprising a control circuit operably coupled to a control terminal of the current control component, and configured to provide one of a plurality of different control signals at the control terminal to write a state into the resistance changing memory element.
8. The memory of claim 6 , wherein the read sense circuit is configured to determine the state of the resistance changing memory element by comparing a current associated therewith with a plurality of reference currents.
9. The memory of claim 6 , wherein the read sense circuit is configured to pre-charge the sense bit line to a predetermined voltage, and then allow the sense bit line to float during the determination of the state of the resistance changing memory element.