A memory system includes a memory device including memory cells, and a controller that performs a write operation, a read operation, and a check operation on the memory device. During the check operation, the controller controls the memory device to read check data from target memory cells of the memory cells by using a check level, compares the check data with original data stored in the target memory cells, and determines a reliability of the target memory cells or the check data based on a result of the comparison.

In example implementations, an integrated characterization vehicle is provided. The integrated characterization vehicle includes a memristor, a configuration cache and an analog measurement tile. The memristor has a driving unit to limit an amount of current that is driven through the memristor during testing. The configuration cache provides test parameters to control the testing of the memristor. The analog measurement tile provides a voltage to the memristor in accordance with the test parameters and to record a response of the memristor.

In example implementations, an integrated characterization vehicle is provided. The integrated characterization vehicle includes a memristor, a configuration cache and an analog measurement tile. The memristor has a driving unit to limit an amount of current that is driven through the memristor during testing. The configuration cache provides test parameters to control the testing of the memristor. The analog measurement tile provides a voltage to the memristor in accordance with the test parameters and to record a response of the memristor.

A logic circuit is provided including at least two input cells and a sense circuit. The input cells are connected to a common result line. Further, the input cells are operable for influencing an electrical quantity at the result line. The sense circuit is connected to the result line, and is adapted to output a discrete value out of more than two possible values based on the electrical quantity.

A logic circuit is provided including at least two input cells and a sense circuit. The input cells are connected to a common result line. Further, the input cells are operable for influencing an electrical quantity at the result line. The sense circuit is connected to the result line, and is adapted to output a discrete value out of more than two possible values based on the electrical quantity.

A method of detecting faults in a register bank is disclosed. The register bank includes at least one chain of registers. The method comprises sequentially shifting parameters stored in each register of the chain to an output node of the chain and inverting each parameter and feeding each parameter back to an input node of that chain, and sequentially shifting the inverted parameters through the chain until all the non-inverted parameters have been output at the output node. A first checksum of the parameters output at the output node is calculated. The inverted parameters in each register of the chain are sequentially shifted to the output node of the chain. A second checksum of the inverted parameters output at the output node is calculated, and the first and second checksums are compared.

A method of detecting faults in a register bank is disclosed. The register bank includes at least one chain of registers. The method comprises sequentially shifting parameters stored in each register of the chain to an output node of the chain and inverting each parameter and feeding each parameter back to an input node of that chain, and sequentially shifting the inverted parameters through the chain until all the non-inverted parameters have been output at the output node. A first checksum of the parameters output at the output node is calculated. The inverted parameters in each register of the chain are sequentially shifted to the output node of the chain. A second checksum of the inverted parameters output at the output node is calculated, and the first and second checksums are compared.

A memory circuit may include a plurality of electrically programmable memory cells arranged in an electrically programmable non-volatile memory cell array along a plurality of rows and a plurality of columns, a plurality of word lines, each word line coupled with a plurality of word portions of the plurality of memory cells, each word portion configured to store a data word, and at least one overlay word line coupled with a plurality of overlay portions, each overlay portion including overlay memory cells, each of the plurality of overlay portions including an overlay word. The memory circuit is configured to read, for each of the plurality of word lines, from each of the word portions simultaneously with an overlay portion of the plurality of overlay portions, with an output of the read operation being a result of a logic operation performed on the data word and the overlay word.

A memory circuit may include a plurality of electrically programmable memory cells arranged in an electrically programmable non-volatile memory cell array along a plurality of rows and a plurality of columns, a plurality of word lines, each word line coupled with a plurality of word portions of the plurality of memory cells, each word portion configured to store a data word, and at least one overlay word line coupled with a plurality of overlay portions, each overlay portion including overlay memory cells, each of the plurality of overlay portions including an overlay word. The memory circuit is configured to read, for each of the plurality of word lines, from each of the word portions simultaneously with an overlay portion of the plurality of overlay portions, with an output of the read operation being a result of a logic operation performed on the data word and the overlay word.

A memory device and a method for test reading and writing thereof are provided. A precharge voltage control circuit is based on the precharge reference voltage to provide a first precharge voltage and a second precharge voltage. A sense amplifier circuit is coupled between a bit line and a complementary bit line and configured to sense data of a memory cell coupled to the bit line, and also coupled to the precharge voltage control circuit to make the bit line and the complementary bit line receive the first precharge voltage and the second precharge voltage respectively, the first precharge voltage and the second precharge voltage are on the same voltage level during the precharge operation, but during a test write sensing period and a test read sensing period after the precharge operation, the voltage levels of the first precharge voltage and the second precharge voltage are different.