An apparatus includes a first group of memory units and a second group of memory units coupled to a first data path and a second data path coupled to a controller, a first delay element on the first data path coupled to the second group of memory units and configured to send, from the controller to the second group of memory units, signals for write and read operations in a sequence of time cycles delayed by a time cycle with respect to the first group of memory units, and a second delay element on the second data path and coupled to the first group of memory units and configured to send, from the first group of memory units to the controller, test result signals delayed by a time cycle, the delayed test result signals having a matching delay to the delayed write and read operations.

A flexible RAM loader including a shift register that includes a first data section coupled with a serial data input, and a second data section selectively coupled with a first parallel data input. The shift register is configured to load data serially from the serial data input to the first data section and the second data section when the second data section is uncoupled from the first parallel data input, and, when the second data section is coupled with the first parallel data input, configured to load data in parallel from the serial data input into the first data section and from the first parallel data input into the second data section. The flexible RAM loader also including a test register comprising a selection bit to couple the second data section with the first parallel data input.

A flexible RAM loader including a shift register that includes a first data section coupled with a serial data input, and a second data section selectively coupled with a first parallel data input. The shift register is configured to load data serially from the serial data input to the first data section and the second data section when the second data section is uncoupled from the first parallel data input, and, when the second data section is coupled with the first parallel data input, configured to load data in parallel from the serial data input into the first data section and from the first parallel data input into the second data section. The flexible RAM loader also including a test register comprising a selection bit to couple the second data section with the first parallel data input.

A method for testing a memory chip includes the following: test data is written into memory cells of a memory chip to be tested; stored data is read from memory cells; a test result of the memory chip to be tested is generated according to the test data and the stored data. A current voltage of bit line precharge (VBLP) of the memory chip to be tested is smaller than a standard VBLP of the memory chip to be tested, and/or a current sensing delay time (SDT) of the memory chip to be tested is smaller than a standard SDT of the memory chip to be tested.

A method for testing a memory chip includes the following: test data is written into memory cells of a memory chip to be tested; stored data is read from memory cells; a test result of the memory chip to be tested is generated according to the test data and the stored data. A current voltage of bit line precharge (VBLP) of the memory chip to be tested is smaller than a standard VBLP of the memory chip to be tested, and/or a current sensing delay time (SDT) of the memory chip to be tested is smaller than a standard SDT of the memory chip to be tested.

Memory devices, systems including memory devices, and methods of operating memory devices are described, in which security measures may be implemented to control access to a fuse array (or other secure features) of the memory devices based on a secure access key. In some cases, a customer may define and store a user-defined access key in the fuse array. In other cases, a manufacturer of the memory device may define a manufacturer-defined access key (e.g., an access key based on fuse identification (FID), a secret access key), where a host device coupled with the memory device may obtain the manufacturer-defined access key according to certain protocols. The memory device may compare an access key included in a command directed to the memory device with either the user-defined access key or the manufacturer-defined access key to determine whether to permit or prohibit execution of the command based on the comparison.

Apparatuses, systems, and methods for self-test mode abort circuit. Memory devices may enter a self-test mode and perform testing operations on the memory array. During the self-test mode, the memory device may ignore external communications. The memory includes an abort circuit which may terminate the self-test mode if it fails to properly finish. For example, the abort circuit may count an amount of time since the self-test mode began and end the self-test mode if that amount of time meets or exceeds a threshold, which may be based off of the expected amount of time for the testing operations to complete.

A trim/test interface in a packaged integrated circuit device prevents high through-current between pins of the IC device and trim/test interface digital logic within the IC device using a floating-pin-tolerant always-on CMOS input buffer. The always-on buffer uses a coupling capacitor at its input to block signals at DC and a weak-latch feedback path to ensure that intermediate or floating inputs are provided through the buffer only at one of two digital levels (e.g., those provided by a ground pin GND and by a high supply voltage pin VDD). The described interfaces and methods provide for false-entry-free test mode activation for IC devices with a low pin count, where there are a limited number of pins to cover all test/trim functions, or in which only analog, no-connect, or failsafe pins are available for trim or test mode entry control or trim or test data input.

A test circuit includes first integration circuit configured to receive first test signal and integrate first test signal to output first integrated signal; second integration circuit configured to receive second test signal and integrate second test signal to output second integrated signal, where first test signal and second test signal are signals inverted with respect to each other, value of first integrated signal is product of duty cycle of first test signal and a voltage amplitude of power supply, and value of second integrated signal is product of duty cycle of second test signal and voltage amplitude of power supply; and comparison circuit connected to first and second integration circuits. The comparison circuit is configured to output high-level signal in response to first integrated signal being greater than second integrated signal, and output low-level signal in response to second integrated signal being greater than first integrated signal.

A test circuit includes first integration circuit configured to receive first test signal and integrate first test signal to output first integrated signal; second integration circuit configured to receive second test signal and integrate second test signal to output second integrated signal, where first test signal and second test signal are signals inverted with respect to each other, value of first integrated signal is product of duty cycle of first test signal and a voltage amplitude of power supply, and value of second integrated signal is product of duty cycle of second test signal and voltage amplitude of power supply; and comparison circuit connected to first and second integration circuits. The comparison circuit is configured to output high-level signal in response to first integrated signal being greater than second integrated signal, and output low-level signal in response to second integrated signal being greater than first integrated signal.