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MRAM does not have a block erase function like a Flash device. The time it takes to erase the entire device data would be the time required to write a known bit to each memory cell. It's a simple computation depending upon the device. Take the fastest write time by the number of words and that's your answer.

The device may operate at the lower voltage, however, Everspin does not test this and does not warranty operation outside the data sheet parameters.

The MR25H256 is not a drop in replacement for the FM25V02. The Ramtron part is a 2-wire interface. Our device is a SPI interface (4-5 wire device, depending on how it's used).

The cross for the Cypress CY14B256LA-SZ25XI is the MR256A08B.

Yes, the MR0A08BSO35 will drop into the CY14B101LA-SZ25XIT. The only difference is the access time (35 ns vs. 25 ns). Also, the Everspin device does not require the "Software STORE" and "Software RECALL" commands. Reading from or writing to the address locations in the Everspin device required by the Cypress "Store/Restore" commands should not affect the Everspin device, so we do not believe you need to make software/firmware changes. However, we encourage your software team to conduct their own tests regarding this issue to confirm compatibility.

The exposed pad on the bottom of the device is part of the lead frame which is internally connected to Vss. The optimal design is to place a ground pad on the PCB under the device and solder the bottom pad to it. While this is not a requirement, connecting the bottom pad to Vss will improve noise immunity and act as a heat sink. We recommend that you not route traces under the device.

See the Memory Protection Modes table in the data sheet. The WEL bit must be set to protect both protected as well as unprotected data blocks

Tin Matte, applied by electroplating. Thickness 8/25um. No nickle barrier. Not annealed.

Generally, not at this time for parallel interface MRAM.

A write is performed on the rising edge of either of the CE#, WE# or U#/LB#.

Automotive, industrial control equipment, servers, RAID systems, gaming machines, avionics and many more.  Everspin MRAMs are applicable in any application that would use an SRAM or DRAM.

The unit of magnetic field Oersted (Oe) is from the CGS unit system. In the SI unit system the unit of magnetic field is Ampere/meter (A/m). The conversion between is 1 Oe = 79.6 A/m.

The magnetic fields generated by the MRAM device are very small and localized. In addition Everspin MRAM devices are shielded with a soft magnetic material that contains any flux generated from within the device. You shouldn't need to take any precautions in regards to shielding other devices from MRAM magnetic fields.

Everspin MRAMs have absolute maximum magnetic field specifications comparable to Hard Disk drives.

Typical magnetized tools, such as screwdrivers with magnetically attached bits, can be used safely around unpowered MRAM without any negative effect, provided the tool is kept at least one millimeter away from the MRAM device. Care should be taken to avoid direct contact with the MRAM package. As with any electronic component, it is not advisable to use tools in close proximity to actively powered circuits.

Yes. The International Electrotechnical Commission IEC 61000-4-8: Electromagnetic compatibility (EMC) - Part 4-8: Power frequency magnetic field immunity test. This relates to the immunity requirements of equipment to magnetic disturbances at power frequency. The maximum specification for continuous fields is 100 A/m (1.3 Oe) and for pulsed field 1000 A/m (13 Oe), both much lower than the MRAM absolute maximum field spec during write of 2000 A/m (25 Oe).

test

All Everspin MRAM devices are built into packages with integrated magnetic shields that provide significant protection from locally strong magnetic fields. Each MRAM product is qualified and rated to be immune to magnetic fields up to a specified maximum. The absolute maximum rating for exposure to external magnetic fields is different for each MRAM and is given in each product datasheet.

Everspin MRAM standard product magnetic shielding provides excellent immunity to magnetic influence in all general applications. Everspin will always be looking for ways to increase immunity to external magnetic fields and changes will be announced whenever we have developed a qualified product with increased immunity. Specific immunity specifications for any product are available in the product data sheet.

The invalid code will be ignored by the device.

The truncated last byte is not written to memory.