摘要:
A process variation detection apparatus and a process variation detection method are provided. The process variation detection apparatus includes a process variation detector and a compensation signal generator. The process variation detector includes a first process variation detection component, a second process variation detection component and a current comparator. The channel of the first process variation detection component is a first conductive type, and the channel of the second process variation detection component is a second conductive type, wherein the above-mentioned first conductive type is different from the second conductive type. The current comparator is connected to the first process variation detection component and the second process variation detection component for comparing the current difference between the two components and outputting a current comparison result. The compensation signal generator is connected to the process variation detector, and produces a corresponding compensation signal according to the current comparison result.
摘要:
A voltage compensation circuit, a multi-level memory device with the same, and a voltage compensation method for reading the multi-level memory device are provided. When a memory cell is read, a reference voltage applied to the memory device is adjusted according to variation of characteristics of a drift resistance of a reference cell. The increased value of the reference voltage (i.e. a voltage difference) corresponds to a resistance variation caused by a drift condition. The drift compensation mechanism is adaptive to a compensation circuit of a read driver of the memory device, which can compensate variation of the voltage level when data is read from the memory cell. When the resistance drift occurs, a drift amount is calculated and is added to the reference voltage, in order to avoid the error in judgement caused by the resistance drift when the stored data is read out.
摘要:
A resistive random access memory (RRAM) and a verifying method thereof are provided. The RRAM comprises at least one resistive memory cell. The resistive memory cell comprises a resistive memory element and a transistor, wherein one terminal of the resistive memory element is coupled to a first terminal of the transistor. The verifying method comprises the following steps: Whether the resistive memory cell passes verification is determined. During a first time period and under the circumstance that the resistive memory cell fails to pass verification, a reference voltage is applied to the other terminal of the resistive memory element and a voltage pulse is applied to a second terminal of the transistor according to a voltage signal to write a reverse voltage to the resistive memory cell.
摘要:
A resistive random access memory (RRAM) and a verifying method thereof are provided. The RRAM comprises at least one resistive memory cell. The resistive memory cell comprises a resistive memory element and a transistor, wherein one terminal of the resistive memory element is coupled to a first terminal of the transistor. The verifying method comprises the following steps: Whether the resistive memory cell passes verification is determined. During a first time period and under the circumstance that the resistive memory cell fails to pass verification, a reference voltage is applied to the other terminal of the resistive memory element and a voltage pulse is applied to a second terminal of the transistor according to a voltage signal to write a reverse voltage to the resistive memory cell.
摘要:
A voltage compensation circuit, a multi-level memory device with the same, and a voltage compensation method for reading the multi-level memory device are provided. When a memory cell is read, a reference voltage applied to the memory device is adjusted according to variation of characteristics of a drift resistance of a reference cell. The increased value of the reference voltage (i.e. a voltage difference) corresponds to a resistance variation caused by a drift condition. The drift compensation mechanism is adaptive to a compensation circuit of a read driver of the memory device, which can compensate variation of the voltage level when data is read from the memory cell. When the resistance drift occurs, a drift amount is calculated and is added to the reference voltage, in order to avoid the error in judgement caused by the resistance drift when the stored data is read out.
摘要:
A process variation detection apparatus and a process variation detection method are provided. The process variation detection apparatus includes a process variation detector and a compensation signal generator. The process variation detector includes a first process variation detection component, a second process variation detection component and a current comparator. The channel of the first process variation detection component is a first conductive type, and the channel of the second process variation detection component is a second conductive type, wherein the above-mentioned first conductive type is different from the second conductive type. The current comparator is connected to the first process variation detection component and the second process variation detection component for comparing the current difference between the two components and outputting a current comparison result. The compensation signal generator is connected to the process variation detector, and produces a corresponding compensation signal according to the current comparison result.
摘要:
A phase change memory with an operating current that can be gradually increased or gradually decreased. The phase change memory has a phase change storage element, a transistor, and a control circuit. The transistor is operable to adjust the operating current flowing through the phase change storage element. The transistor has a first terminal coupled to a voltage source, a second terminal coupled to the phase change storage element, and a control terminal receiving a control signal from the control circuit. The control circuit is specially designed to limit the transistor in a linear region.
摘要:
A verification circuit for a phase change memory array is provided. A sensing unit senses a sensing voltage from a memory cell of the phase change memory array according to an enable signal. A comparator generates a comparing signal according to the sensing voltage and a reference voltage, so as to indicate whether the memory cell is in a reset state. A control unit generates a control signal according to the enable signal. An operating unit generates a first signal according to the control signal, so as to indicate whether the comparator is active. An adjustment unit provides a writing current to the cell, and increases the writing current according to the control signal until the comparing signal indicates that the memory cell is in a reset state.
摘要:
A phase change memory (PCM) in which the phase change storage element is crystallized by a gradually increasing/decreasing operating current. The PCM comprises a switching circuit, the phase change storage element, a bit select switch, a pulse generating module, and a counting module. The switching circuit comprises a plurality of switches, selectively providing branch paths to an output terminal of a current source. The bit select switch controls the conduction between the phase change storage element and the output terminal of the current source. The pulse generating module outputs a pulse signal oscillating between high and low voltage levels. When enabled, the counting module counts the oscillations of the pulse signal, and outputs the count result by a set of digital data. The set of digital data are coupled to the switching circuit to control the switches therein.
摘要:
An embodiment of a writing system for a phase change memory based on a present application is disclosed. The writing system comprises a first phase change memory (PCM) cell, a second PCM cell, a first writing circuit and a verifying circuit. The first writing circuit executes a writing procedure, receives and writes a first data to the first PCM cell. The verifying circuit executes a verifying procedure and the circuit further comprises a processing unit and a second writing circuit. The processing unit reads and compares the data stored in the second PCM cell with a second data. The second writing circuit writes the second data to the second PCM cell when the data stored in the second PCM cell and the second data are not matched.