Everspin recently announced they have begun pilot production of their 1Gb STT-MRAM (Spin-transfer Torque Magnetoresistive RAM) nonvolatile memory, after shipping the first pre-production samples in December. The new MRAM parts are fabbed on a GlobalFoundries 28nm process and are a significant advance in density and capacity compared to their current 40nm 256Mb parts. Production will be ramping up through the second half of this year.
The new parts offer 8-bit or 16-bit DDR4 interfaces at 1333MT/s (667MHz), but as with the older DDR3-based MRAM components, timing differences mean they’re not necessarily a drop-in replacement for DRAM. Low capacities have kept discrete MRAM components largely confined to embedded systems, where SoCs and ASICs can more easily be designed with compatible DDR controllers. The new 1Gb capacity will significantly broaden the appeal of MRAM, but Everspin still has a ways to go before catching up to the density of DRAM. We don’t expect to see much in the way of MRAM-only storage devices yet (SSDs or NVDIMMs), but there will probably be more uses along the lines of the hybrid SSDs we’ve seen that still rely on NAND flash as the primary storage medium but replace some or all of the capacitor-backed DRAM with MRAM: IBM’s FlashCore Module introduced last year, and a Seagate prototype shown at FMS 2017.
Everspin isn’t the only company working on MRAM technology, but they are the the only supplier of discrete MRAM parts, as opposed to embedded on-die MRAM for ASICs. This is the second generation of discrete MRAM parts Everspin has produced in partnership with GlobalFoundries, and they also have embedded MRAM on the roadmap for GloFo’s 22nm FD-SOI process. Since GlobalFoundries cancelled plans for 7nm and smaller processes, specialized processes including embedded memories like Everspin’s MRAM have become crucial to their new future.