A method of improving stability of a memory device having a controller configured to program each of a plurality of non-volatile memory cells within a range of programming states bounded by a minimum program state and a maximum program state. The method includes testing the memory cells to confirm the memory cells are operational, programming each of the memory cells to a mid-program state, and baking the memory device at a high temperature while the memory cells are programmed to the mid-program state. Each memory cell has a first threshold voltage when programmed in the minimum program state, a second threshold voltage when programmed in the maximum program state, and a third threshold voltage when programmed in the mid-program state. The third threshold voltage is substantially at a mid-point between the first and second threshold voltages, and corresponds to a substantially logarithmic mid-point of read currents.

A non-limiting example includes data storage circuitry. The data storage circuitry includes a built-in self-test (BIST) engine. The data storage circuitry includes a memory array including memory cells. The memory array is configured to store data based on a read-write vector associated with an address vector that includes memory addresses and according to a bit-write vector that defines bit-write enablement for the memory addresses. The memory array is configured to output a stored data vector. The data storage circuitry includes a selector configured to receive the bit-write vector, and to output a selected vector based on an initialization vector and a comparison vector based at least in part on the bit-write vector. The data storage circuitry includes a comparator configured to receive the stored data vector and the selected vector, and to output an error based on discrepancies between the stored data vector and the selected vector.

A memory device having non-volatile memory cells and a controller. In response to a first command for erasing and programming a first group of the memory cells, the controller determines the first group can be programmed within substantially 10 seconds of their erasure, erases the first group, and programs the first group within substantially 10 seconds of their erasure. In response to a second command for erasing and programming a second group of the memory cells, the controller determines that the second group cannot be programmed within substantially 10 seconds of their erasure, divides the second group into subgroups of the memory cells each of which can be programmed within substantially 10 seconds of their erasure, and for each of the subgroups, erase the subgroup and program the subgroup within substantially 10 seconds of their erasure.

Embodiments of the present invention are directed to methods, systems, and circuitry for memory arrays. A system for testing a memory array having self-test circuitry includes a register having register latches operable to receive error logic signals having respective first states or second states. The register latches are arranged in series having respective latch inputs cascaded with preceding latch outputs operable to shift the error logic signals to a serial output according to a control signal that is common to the register latches. The system includes an aggregate latch operable to receive the serial output and having input logic configured to maintain a first state of the aggregate latch until the serial output is a second state. The system includes a built-in self-test (BIST) engine including stored instructions operable upon execution by the BIST engine to output the control signal.

A memory device having non-volatile memory cells and a controller. In response to a first command for erasing and programming a first group of the memory cells, the controller determines the first group can be programmed within substantially 10 seconds of their erasure, erases the first group, and programs the first group within substantially 10 seconds of their erasure. In response to a second command for erasing and programming a second group of the memory cells, the controller determines that the second group cannot be programmed within substantially 10 seconds of their erasure, divides the second group into subgroups of the memory cells each of which can be programmed within substantially 10 seconds of their erasure, and for each of the subgroups, erase the subgroup and program the subgroup within substantially 10 seconds of their erasure.

A method of improving stability of a memory device having a controller configured to program each of a plurality of non-volatile memory cells within a range of programming states bounded by a minimum program state and a maximum program state. The method includes testing the memory cells to confirm the memory cells are operational, programming each of the memory cells to a mid-program state, and baking the memory device at a high temperature while the memory cells are programmed to the mid-program state. Each memory cell has a first threshold voltage when programmed in the minimum program state, a second threshold voltage when programmed in the maximum program state, and a third threshold voltage when programmed in the mid-program state. The third threshold voltage is substantially at a mid-point between the first and second threshold voltages, and corresponds to a substantially logarithmic mid-point of read currents.

A memory device that includes a plurality of non-volatile memory cells and a controller. The controller is configured to erase the plurality of memory cells, program each of the memory cells, and for each of the memory cells, measure a threshold voltage applied to the memory cell corresponding to a target current through the memory cell in a first read operation, re-measure a threshold voltage applied to the memory cell corresponding to the target current through the memory cell in a second read operation, and identify the memory cell as defective if a difference between the measured threshold voltage and the re-measured threshold voltage exceeds a predetermined amount.

Embodiments of the present invention are directed to methods, systems, and circuitry for memory arrays. A system for testing a memory array having self-test circuitry includes a register having register latches operable to receive error logic signals having respective first states or second states. The register latches are arranged in series having respective latch inputs cascaded with preceding latch outputs operable to shift the error logic signals to a serial output according to a control signal that is common to the register latches. The system includes an aggregate latch operable to receive the serial output and having input logic configured to maintain a first state of the aggregate latch until the serial output is a second state. The system includes a built-in self-test (BIST) engine including stored instructions operable upon execution by the BIST engine to output the control signal.

A non-limiting example includes data storage circuitry. The data storage circuitry includes a built-in self-test (BIST) engine. The data storage circuitry includes a memory array including memory cells. The memory array is configured to store data based on a read-write vector associated with an address vector that includes memory addresses and according to a bit-write vector that defines bit-write enablement for the memory addresses. The memory array is configured to output a stored data vector. The data storage circuitry includes a selector configured to receive the bit-write vector, and to output a selected vector based on an initialization vector and a comparison vector based at least in part on the bit-write vector. The data storage circuitry includes a comparator configured to receive the stored data vector and the selected vector, and to output an error based on discrepancies between the stored data vector and the selected vector.

A data sampling circuit includes a frequency dividing circuit, a sampling circuit and a selection circuit. The frequency dividing circuit is configured to receive a first data sampling signal, and perform frequency dividing processing on the first data sampling signal to obtain multiple second data sampling signals associated with respective phases; the sampling circuit is configured to receive the multiple second data sampling signals and a first data signal, and sample the first data signal according to the multiple second data sampling signals to obtain multiple second data signals associated with respective phases; and the selection circuit is configured to receive preamble information and mode register set (MRS) information, and select among the multiple second data sampling signals and the plurality of second data signals according to the preamble information and the MRS information to obtain a target data sampling signal and a target data signal respectively.