From time to time I am asked: “Why is NAND flash called NAND?” or “Why do we say RAM?” and similar questions. A lot of this has to do with history, and a lot of terminology which is now obsolete. To understand these strange names, you have to understand the history of memories. The Computer History Museum (CHM) in Silicon Valley is a great help in this vein.
Since the Memory Guy has been in Silicon Valley since 1977, a lot of this information is stored in my head. Let me try to share it with you in a way that I hope will make more sense, and will help outsiders to understand these odd names.
Here’s the history of memory nomenclature, as I understand it: Continue reading
Just in case anyone thought that NOR flash was not going to get any denser, Spansion announced a single-chip 8Gb parallel NOR today. This product, built using Spansion’s MirrorBit technology on a 45nm line is not only the densest monolithic NOR chip on the market, it’s also the NOR flash with the finest process technology.
Spansion’s GL-T product is aimed at applications that need high densities at read speeds faster than those that NAND flash can deliver. Spansion tells The Memory Guy that read performance is 95MB/s and program performance is 1.8 MB/s.
Sampling will commence in December, with production in the first quarter of 2013.
Today I saw an announcement from another market research firm about a new report with flash memory market shares for 2011. I found it remarkable that the way these chips are counted varies enough that the company decided to openly discuss this issue right in the press release for the report!
Memory market statistics are compiled by numerous firms: The World Semiconductor Trade Statistics (WSTS) sold in the US and Europe by the Semiconductor Industry Association (SIA), Gartner Dataquest, IHS iSuppli, Web Feet, Semico, Forward Insights, and even DRAMexchange. Lots of entities use conflicting definitions of what is and what is not a chip. This causes each company’s numbers to differ from the others’.
In the case of WSTS, a chip that is packaged with another chip into a board becomes Continue reading
SK Hynix and Spansion have announced a strategic NAND alliance under which Hynix will serve as a foundry for low-density SLC NAND chips made for Spansion using Hynix’ advanced processing nodes.
These products, aimed at the embedded market, should serve to strengthen Spansion in a market in which the company thrives. In fact, Spansion expressed this very well in their press release, citing: “Spansion’s recognized customer support and commitment for longevity of supply, which is highly valued in the embedded market, where Spansion has established relationships.”
The new chips will be manufactured in “4x, 3x, and 2xnm” process technologies.
The companies have also agreed to cross-license their patent portfolios.
You may be asking yourself: “What does Hynix Continue reading
Nostalgia buffs who lived through computing in the 1970s will enjoy some magnificent photos shared in comments to a Microcontroller Central blog post. The photos, shared by Ryszard Milewicz, give a close-up view of a ferrite core memory plane. The photo from this blog is a part of one of Mr. Milewicz’ photos.
For those who were not exposed to core, this technology was based upon an approach in which every individual bit of a computer’s memory was a tiny donut made of compressed iron powder (“Ferrite”) that had to be hand strung with copper wire into a plane of bits.
The IEEE Spectrum published an interesting article postulating that Russia’s recently-failed Mars probe may have suffered from bad memory chips. According to the Spectrum article the Russian government’s Official Accident Investigation Results faulted SRAMs:
The report blames the loss of the probe on memory chips that became fatally damaged by cosmic rays.
Both the main computer and the backup computer seem to have failed at the same time, Continue reading
The current battle between Cypress Semiconductor and GSI Technology caught The Memory Guy’s eye recently. Many readers may have missed this battle that commenced when Cypress filed a Federal Trade Commission (FTC) lawsuit in the US in which the company asked for GSI SRAMs to be barred from importation into the US because of a patent dispute.
GSI has issued a countersuit with a complaint of anticompetitive practices.
What garnered my interest is how similar the tactics in this lawsuit are to those used for some of the Rambus lawsuits that evolved over the years: Continue reading
What is a Content-Addressable Memory (CAM)? The Memory Guy decided to post this after having recently run across a very strange web post HERE that erroneously inferred that CAM chips from NEC could be a threat to NAND-based SSDs. The article was based on a press release from NEC and Tohoku University that can be read HERE.
It’s not at all surprising that the release was misunderstood – it’s very awkwardly written:
The new CAM utilizes the vertical magnetization of vertical domain wall elements in reaction to magnetic substances in order to enable data that is processing within the CAM to be stored on a circuit without using power.