Memory devices, systems including memory devices, and methods of operating memory devices and systems are provided, in which at least a subset of a non-volatile memory array is configured to behave as read-only memory by not implementing erase or write commands. In one embodiment of the present technology, a memory device is provided, comprising a non-volatile memory array, and circuitry configured to store one or more addresses of the non-volatile memory array, to compare an address of a received command to the one or more addresses, and at least in part based on the comparison, determine not to implement the received command. The circuitry can be further configured to return an error message after determining not to implement the received command.

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.

A magnetic random access memory (MRAM) array includes a plurality of MRAM cells, each of the MRAM cells including a magnetic tunnel junction (MTJ) stack disposed on a bottom metal via connecting the MTJ stack to a bottom conductive contact in a substrate, a plurality of top conductive contacts, each of the top conductive contacts disposed on a respective one of the MTJ stacks, and a plurality of unitary structures configured as a heat sink/magnetic shield disposed on a vertical portions of each of the MRAM cells, including vertical portions of the bottom metal vias, and under a portion of each of the MTJ stacks.

Devices are disclosed. A device may include a source configured to couple to a number of memory cells. The device may also include at least one transistor coupled between the source and a ground voltage. Further, the device may include an antifuse coupled between the at least one transistor and the ground voltage. Methods and systems are also disclosed.

A packaged integrated circuit includes a photodiode and a memory. The photodiode generates energy when radiation strikes a surface of the photodiode. The memory includes a plurality of non-volatile memory cells and memory control circuitry. The memory control circuitry is configured to perform an operation to change values stored in at least some of the memory cells of the plurality of non-volatile memory cells while being powered by energy generated by the photodiode. An encapsulant at least partially encapsulates the photodiode and the memory, in which the encapsulant blocks radiation from reaching the surface of the photodiode.

Technology for limiting a voltage difference between two selected conductive lines in a cross-point array when using a forced current approach is disclosed. In one aspect, the selected word line voltage is clamped to a voltage limit while driving an access current through a region of the selected word line and through a region of the selected bit line. The access current flows through the memory cell to allow a sufficient voltage to successfully read or write the memory cell, while not placing undue stress on the memory cell. In some aspects, the maximum voltage that is permitted on the selected word line depends on the location of the selected memory cell in the cross-point memory array. This allows memory cells for which there is a larger IR drop to receive an adequate voltage, while not over-stressing memory cells for which there is a smaller IR drop.

Systems, apparatuses, and methods related to a computer system having a page table entry containing permission bits for predefined types of memory accesses made by executions of routines in predefined domains are described. The page table entry can be used to map a virtual memory address to a physical memory address. In response to a routine accessing the virtual memory address, a permission bit corresponding to the execution domain of the routine and a type of the memory access can be extracted from the page table entry to determine whether the memory access is to be rejected.

Devices are disclosed. A device may include a source configured to couple to a number of memory cells. The device may also include at least one transistor coupled between the source and a ground voltage. Further, the device may include an antifuse coupled between the at least one transistor and the ground voltage. Methods and systems are also disclosed.

Technology for limiting a voltage difference between two selected conductive lines in a cross-point array when using a forced current approach is disclosed. In one aspect, the selected word line voltage is clamped to a voltage limit while driving an access current through a region of the selected word line and through a region of the selected bit line. The access current flows through the memory cell to allow a sufficient voltage to successfully read or write the memory cell, while not placing undue stress on the memory cell. In some aspects, the maximum voltage that is permitted on the selected word line depends on the location of the selected memory cell in the cross-point memory array. This allows memory cells for which there is a larger IR drop to receive an adequate voltage, while not over-stressing memory cells for which there is a smaller IR drop.

Technology for limiting a voltage difference between two selected conductive lines in a cross-point array when using a forced current approach is disclosed. In one aspect, the selected word line voltage is clamped to a voltage limit while driving an access current through a region of the selected word line and through a region of the selected bit line. The access current flows through the memory cell to allow a sufficient voltage to successfully read or write the memory cell, while not placing undue stress on the memory cell. In some aspects, the maximum voltage that is permitted on the selected word line depends on the location of the selected memory cell in the cross-point memory array. This allows memory cells for which there is a larger IR drop to receive an adequate voltage, while not over-stressing memory cells for which there is a smaller IR drop.