摘要:
Disclosed is an across-chip temperature sensing circuit and an associated method that can be used to profile the across-chip temperature gradient. The embodiments incorporate a plurality of phase change elements distributed approximately evenly across the semiconductor chip. These phase change elements are programmed to have essentially the same amorphous resistance. Temperature-dependent behavior exhibited by each of the phase change elements individually is compared to a reference (e.g., generated by a discrete reference phase change element, generated by another one of the phase change elements, or generated by an external reference) in order to profile the temperature gradient across the semiconductor chip. Once profiled, this temperature gradient can be used to redesign and/or relocate functional cores, to set stress limits for qualification of functional cores and/or to adjust operating specifications of functional cores.
摘要:
Disclosed is an across-chip temperature sensing circuit and an associated method that can be used to profile the across-chip temperature gradient. The embodiments incorporate a plurality of phase change elements distributed approximately evenly across the semiconductor chip. These phase change elements are programmed to have essentially the same amorphous resistance. Temperature-dependent behavior exhibited by each of the phase change elements individually is compared to a reference (e.g., generated by a discrete reference phase change element, generated by another one of the phase change elements, or generated by an external reference) in order to profile the temperature gradient across the semiconductor chip. Once profiled, this temperature gradient can be used to redesign and/or relocate functional cores, to set stress limits for qualification of functional cores and/or to adjust operating specifications of functional cores.
摘要:
One embodiment is a non-volatile memory cell with random access read, program, and erase. The memory cell includes a cell transistor that includes a source region, a drain region, a first insulating spacer, and a second insulating spacer. The memory cell also includes a source-side transistor, a drain-side transistor, a source-side multiplexer, a drain-side multiplexer, a source-side sense amplifier, and a drain-side write driver. A first binary value is stored in a first bit in the memory cell by trapping or releasing a first electric charge in the first insulating spacer. The first bit is read by sensing the resistive change in the cell transistor or by sensing the threshold voltage change in the cell transistor.
摘要:
An apparatus for sensing the data state of a multiple level, programmable resistive memory device includes an active clamping device connected to a data leg that is selectively coupled a programmable resistive memory element, the clamping device configured to clamp a fixed voltage, at a first node of the data leg, across the memory element, thereby establishing a fixed current sinking capability thereof; and a plurality of differential amplifiers, each of the differential amplifiers configured to compare a first voltage input, taken at a second node of the data leg, with a second voltage input; wherein the second voltage input for each differential amplifier comprises different reference voltages with respect to one another so as to enable each differential amplifier to detect a different resistance threshold, thereby determining a specific resistance state of the programmable resistive memory element.
摘要:
A precision sense amplifier apparatus includes a current source configured to introduce an adjustable reference current through a reference leg; a current mirror configured to mirror the reference current to a data leg, the data leg selectively coupled to a programmable resistance memory element; an active clamping device coupled to the data leg, and configured to clamp a fixed voltage across the memory element, thereby establishing a fixed current sinking capability thereof; and a differential sense amplifier having a first input thereof coupled to the data leg and a second input thereof coupled to the reference leg; wherein an output of the differential sense amplifier assumes a first logic state whenever the reference current is less than the fixed current sinking capability of the memory element, and assumes a second logic state whenever the reference current exceeds the fixed current sinking capability.
摘要:
An apparatus for sensing the data state of a multiple level, programmable resistive memory device includes an active clamping device connected to a data leg that is selectively coupled a programmable resistive memory element, the clamping device configured to clamp a fixed voltage, at a first node of the data leg, across the memory element, thereby establishing a fixed current sinking capability thereof; and a plurality of differential amplifiers, each of the differential amplifiers configured to compare a first voltage input, taken at a second node of the data leg, with a second voltage input; wherein the second voltage input for each differential amplifier comprises different reference voltages with respect to one another so as to enable each differential amplifier to detect a different resistance threshold, thereby determining a specific resistance state of the programmable resistive memory element.
摘要:
A phase change memory (PCM) cycle timer and associated method are disclosed. A system includes at least one reference phase change element (PCE). The system also includes a circuit that performs a write operation on the at least one reference PCE and substantially immediately thereafter continuously senses and returns a value of a resistance of the at least one reference PCE throughout a settling time of the at least one reference PCE.
摘要:
A method of implementing a self-referencing read operation for a PCRAM array includes applying a stimulus to a bit line associated with a selected phase change element (PCE) to be read; comparing a first voltage on a node of the bit line with a second voltage on a delay node, wherein the second voltage represents a delayed voltage with respect to the first voltage due to a resistance/capacitance time constant associated therewith; and determining whether, during the read operation, the first voltage drops below the value of the second voltage; wherein in the event the first voltage drops below the value of the second voltage during the read operation, the PCE is determined to be programmed to an amorphous state and in the event the first voltage does not drop below the value of the second voltage, the PCE is determined to be programmed to a crystalline state.
摘要:
A precision sense amplifier apparatus includes a current source configured to introduce an adjustable reference current through a reference leg; a current mirror configured to mirror the reference current to a data leg, the data leg selectively coupled to a programmable resistance memory element; an active clamping device coupled to the data leg, and configured to clamp a fixed voltage across the memory element, thereby establishing a fixed current sinking capability thereof; and a differential sense amplifier having a first input thereof coupled to the data leg and a second input thereof coupled to the reference leg; wherein an output of the differential sense amplifier assumes a first logic state whenever the reference current is less than the fixed current sinking capability of the memory element, and assumes a second logic state whenever the reference current exceeds the fixed current sinking capability.
摘要:
An Off Chip Driver (OCD) having a high, a low and a high impedance (Hi-Z) state. The OCD includes an up-level pre-drive, a down-level pre-drive and a driver. The driver mirrors current in the up-level pre-drive and down-level pre-drive. Both pre-drive circuits have an unbalanced input-dependant delay to quickly turn off/on the on and off driver devices and, after a delay, reduce the drive on the turned on device to a steady state level. The delay may have a fixed length set by an inverter chain or may be dependent upon output voltage.