Micron Launches Phase-Change Memory for Mobile Devices
Company claims to be first in the industry to make available high quantities of its 45-nanometer phase-change memory chip.Is phase-change memory, acronymed PCM and discussed for the last six years as a potential replacement for NAND flash, finally ready for prime time? Solid-state semiconductor maker Micron Technology July 17 claimed to be the first in the industry to make available high volumes of its 45-nanometer phase-change memory chip for mobile devices. The Boise, Idaho-based company's 45nm PCMs are targeted for high-end feature-type phones, with its longer-range strategy to build them for smartphones and tablet PCs.
The new processors (wafer pictured at left) feature 1G-bit PCM plus 512M-bit LPDDR2 (Low Power Double Data Rate memory, also known as Mobile DDR, or MDDR) in a multichip package.
NAND flash is inherently slowed down by so-called erase-write cycle limitations. This is because NAND flash requires that data first be marked for deletion before new data is written to the disk, which slows the process considerably. PCM does not require erase-write cycles. Thus, the extra erase-write activity causes NAND flash performance to degrade faster and, over time, wear out the disk. Typically, NAND flash disk life spans range from 5,000 to 10,000 write cycles in consumer disks and up to 100,000 cycles in enterprise-class disks. In contrast, PCM can handle up to an estimated 5 million write cycles. Micron, IBM and Intel contend PCM also provides enhanced boot time and simplifies software development, thanks to its inherent speed. It also provides low power consumption and high reliability, Micron said. In addition, the design-optimizing shared interface between LPDDR2 and PCM is fully compliant with JEDEC (Joint Electron Devices Engineering Council) industry standards, Micron said.