One-time programming (OTP) magneto-resistive random access memory (MRAM) bit cells in a physically unclonable function (PUF) memory in breakdown to a memory state from a previous read operation to provide PUF operations is disclosed. PUF memory is configured to permanently one-time program an initial randomly generated PUF output from PUF MRAM bit cells accessed in an initial PUF read operation, to the same PUF MRAM bit cells accessed in the initial PUF read operation. In this manner, the initial PUF output is randomly generated due to process variations of the PUF MRAM bit cells to maintain an initial unpredictable memory state, but the PUF output will be reproduced for subsequent PUF read operations to the same PUF MRAM bit cells in the PUF memory array for reproducibility. The OTP of the PUF MRAM bit cells can be accomplished by applying breakdown voltage to the PUF MRAM bit cells during programming.

A magnetic memory device includes a plurality of first bit lines and a plurality of second bit lines, a plurality of first source lines respectively corresponding to the plurality of first bit lines and a plurality of second source lines respectively corresponding to the plurality of second bit lines, a plurality of first memory cells connected between the plurality of first bit lines and the plurality of first source lines, respectively, in a first region, the plurality of first memory cells respectively including a first memory device and a first selection transistor, and a plurality of second memory cells connected between the plurality of second bit lines and the plurality of second source lines, respectively, in a second region, the plurality of second memory cells respectively including a second memory device and a second selection transistor.

Magnetic tunnel junction (MTJ) devices with varied breakdown voltages in different memory arrays fabricated in a same semiconductor die to facilitate different memory applications are disclosed. In exemplary aspects disclosed herein, MTJ devices are fabricated in a semiconductor die to provide at least two different memory arrays. MTJ devices in each memory array are fabricated to have different breakdown voltages. For example, it may be desired to fabricate a One-Time-Programmable (OTP) memory array in the semiconductor die using MTJ devices having a first, lower breakdown voltage, and a separate magneto-resistive random access memory (MRAM) in a same semiconductor die with MTJ devices having a higher breakdown voltage. Thus, in this example, lower breakdown voltage MTJ devices in OTP memory array require less voltage to program, while higher breakdown voltage MTJ devices in MRAM can maintain a desired write operation margin to avoid or reduce write operations causing dielectric breakdown.

A magnetic memory device is provided. The magnetic memory device includes a memory circuit comprising a first tunnel magnetoresistive element and a second tunnel magnetoresistive element coupled in series. An input node of the magnetic memory device is coupled to the first tunnel magnetoresistive element, wherein the input node is configured to receive a voltage signal. The first tunnel magnetoresistive element initially holds a first resistance value, wherein the first tunnel magnetoresistive element is short-circuited to hold a second resistance value after the voltage signal is received by the input node. End nodes of the memory circuit are coupled to defined voltages in a read mode. The magnetic memory device further includes a read-out circuit configured to measure a voltage at a sensing node in the read mode. The sensing node is interconnected between the first tunnel magnetoresistive element and the second tunnel magnetoresistive element.

A circuit and method for adaptive trimming of the reference signal for sensing data during a read operation of magnetic memory cells to improve read margin for the magnetic memory cells. The circuit has a trim one-time programmable memory array programmed with offset trim data applied to magnetic memory array sense amplifiers. Sense amplifier trimming circuits receive and decode the trim data to determine offset trim signal magnitude to adjust the reference signal to improve the read margin. The method sets the offset trim level to each increment of the offset trim level. Data is written and read to the magnetic memory array, the number of errors in the array is accumulated for each setting of the offset trim level. The error levels are compared and the appropriate trim level is programmed to the trim memory cells such that a read margin of the sense amplifier is improved.

A circuit and method for adaptive trimming of the reference signal for sensing data during a read operation of magnetic memory cells to improve read margin for the magnetic memory cells. The circuit has a trim one-time programmable memory array programmed with offset trim data applied to magnetic memory array sense amplifiers. Sense amplifier trimming circuits receive and decode the trim data to determine offset trim signal magnitude to adjust the reference signal to improve the read margin. The method sets the offset trim level to each increment of the offset trim level. Data is written and read to the magnetic memory array, the number of errors in the array is accumulated for each setting of the offset trim level. The error levels are compared and the appropriate trim level is programmed to the trim memory cells such that a read margin of the sense amplifier is improved.

A read only memory including a ROM cell array, a plurality of word lines and a plurality of bit lines and a word line driver. The ROM cell array has a plurality of ROM cells. Each of the ROM cells coupled to corresponding bit line and corresponding word line. The word line driver is coupled to the word lines, and respectively provides a plurality of word line signals to the word lines. Each of the ROM cells is a first type ROM cell or a second type ROM cell. The first type ROM cell includes a first top metal structure and a first bottom metal structure. The first bottom metal structure is electrically isolated from the first top metal structure. The second type ROM cell includes a second top metal structure, a second bottom metal structure, and a connection structure. The connection structure is electrically connected the second top metal structure and the second bottom metal structure.

According to an embodiment, a magnetic storage device includes a first, second, and third magnetoresistive effect elements, and a controller. The second and third magnetoresistive effect elements are in proximity to the first magnetoresistive effect element. When the controller receives an command which is associated with an operation of writing a first data item to the first magnetoresistive effect element, the controller is configured to perform a first operation of writing the first data item to the first magnetoresistive effect element, and a second operation of writing a second data item different from the first data item to the second magnetoresistive effect element and the third magnetoresistive effect element.

A one time programming (OTP) apparatus unit cell includes magnetic tunnel junctions (MTJs) with reversed connections for placing the MTJ in an anti-parallel resistance state during programming. Increased MTJ resistance in its anti-parallel resistance state causes a higher programming voltage which reduces programming time and programming current.

A one time programming (OTP) apparatus unit cell includes magnetic tunnel junctions (MTJs) with reversed connections for placing the MTJ in an anti-parallel resistance state during programming. Increased MTJ resistance in its anti-parallel resistance state causes a higher programming voltage which reduces programming time and programming current.