Freescale Claims Breakthrough in MRAM Memory
July 17, 2006 Timothy Prickett Morgan
Freescale Semiconductor, the chip manufacturing company that was spun out of Motorola, announced last week that it has commercialized a new memory technology called Magnetoresistive Random Access Memory, or MRAM, that looks as if it will shake up the computer business.
Magnetoresistive, or MR, technologies were first commercialized in the disk heads of IBM disk drives created by the Rochester, Minnesota, laboratories–back when Big Blue used to create its own memory and disk storage technologies. Motorola is the first company to commercialize the use of MR technologies in memory chips. MRAM is a non volatile memory technology, like flash memory, which means it does not need electricity to keep its 1s and 0s in order and therefore store information, as Dynamic RAM, or DRAM, does. But MRAM is also designed to have something akin to the speed of static RAM, or SRAM, and uses magnetic fields to flip bits, which means that anything in memory stays in memory, even if the power is turned off. This makes MRAM something of a dream, if you are a systems designer.
Of course, DRAM has speed as well as capacity. The most popular DDR2 Synchronous DRAM comes in 64 Mbit chip capacities and modules that have 1 GB or 2 GB of total capacity; cycle times on this memory range from 3.75 nanoseconds to 5 nanoseconds. Motorola’s first MRAM chip is quite a bit skinnier and a lot slower, being a 4 Mbit device that has a 35 nanosecond read and write cycle time; it costs about $25 a pop. Part of the problem with the speed of this Freescale MRAM is that is was made with a comparatively ancient 180 nanometer chip technology at Freescale. IBM has demonstrated MRAM with cycle times as low as 2 nanoseconds using more modern processes. Flash memory has its limits because it takes microseconds, not nanoseconds, to move data from the cells on the flash memory to the read/write buffer, although once the data is there, it can move at speeds approaching Motorola’s current MRAM.
It would be interesting to see memory makers really push MRAM technologies to the limits and for server makers to stop messing around so much with chip speeds and get MRAM devices, which can compete on price with DRAM and offer many of the benefits of flash memory without the drawbacks. At the very least, MRAM is perfect for replacing the battery-backed SRAM units that sit as front-ends to main memory and disk controllers on a lot of servers.