摘要:
A sense circuit for reading a resistance level of a programmable conductor random access memory (PCRAM) cell is provided. A voltage potential difference is introduced across a PCRAM cell by activating an access transistor from a raised rowline voltage. Both a digit line and a digit complement reference line are precharged to a first predetermined voltage. The cell being sensed has the precharged voltage discharged through the resistance of the programmable conductor memory element of the PCRAM cell. A comparison is made of the voltage read at the digit line and at the reference conductor. If the voltage at the digit line is greater than the reference voltage, the cell is read as a high resistance value (e.g., logic HIGH); however, if the voltage measured at the digit line is lower than that of the reference voltage, the cell is read as a low resistance value (e.g., logic LOW).
摘要:
A variable resistance memory sense amplifier has a built-in offset to assist in switching the sense amplifier when a resistive memory cell is in a low resistance state. The built-in offset can be achieved by varying size, threshold voltage, associated capacity or associated resistance of the transistors within the sense amplifier.
摘要:
The present invention provides an improved write circuit and method for writing a programmable conductor random access memory (PCRAM) cell. The method comprises precharging a bit line to a first voltage and applying a second voltage to a first terminal of a chalcogenide memory element. A second terminal of the chalcogenide memory element is selectively coupled to the bit line to produce a voltage across the memory element sufficient to write a predetermined resistance state into the element. The first voltage may take on two different values to program two different resistance states into the memory element.
摘要:
A sense circuit for reading a resistance level of a programmable conductor random access memory (PCRAM) cell is provided. A voltage potential difference is introduced across a PCRAM cell by activating an access transistor from a raised rowline voltage. Both a digit line and a digit complement reference line are precharged to a first predetermined voltage. The cell being sensed has the precharged voltage discharged through the resistance of the programmable conductor memory element of the PCRAM cell. A comparison is made of the voltage read at the digit line and at the reference conductor. If the voltage at the digit line is greater than the reference voltage, the cell is read as a high resistance value (e.g., logic HIGH); however, if the voltage measured at the digit line is lower than that of the reference voltage, the cell is read as a low resistance value (e.g., logic LOW).
摘要:
A method and apparatus is disclosed for sensing the resistance state of a Programmable Conductor Random Access Memory (PCRAM) element using complementary PCRAM elements, one holding the resistance state being sensed and the other holding a complementary resistance state. A sense amplifier detects voltages discharging through the high and low resistance elements to determine the resistance state of an element being read.
摘要:
The present invention provides an improved write circuit and method for writing a programmable conductor random access memory (PCRAM) cell. The method comprises precharging a bit line to a first voltage and applying a second voltage to a first terminal of a chalcogenide memory element. A second terminal of the chalcogenide memory element is selectively coupled to the bit line to produce a voltage across the memory element sufficient to write a predetermined resistance state into the element. The first voltage may take on two different values to program two different resistance states into the memory element.
摘要:
A variable resistance memory sense amplifier has a built-in offset to assist in switching the sense amplifier when a resistive memory cell is in a low resistance state. The built-in offset can be achieved by varying size, threshold voltage, associated capacity or associated resistance of the transistors within the sense amplifier.