More info about the chips from NEC and MoSys
Found at IGN. (I love this site
)
June 19, 2006 - NEC Electronics announced today that Nintendo has selected the company to provide 90-nanometer CMOS-compatible embedded DRAM technology for the forthcoming Wii console. The new LSI chips with eDRAM will be manufactured on NEC's 300-millimeter production line at Yamagata. While no clock speeds or really juicy info was included in the release, the news does bring up a variety of interesting points.
The official announcement does not come as a great surprise, as NEC and Nintendo have worked closely in the past. NEC provided the eDRAM graphics LSI chips for the GameCube, which it manufactured at its plant in Kyushu, and has also agreed to allow Nintendo to feature classic NEC TurboGrafx-16 games via the Wii's Virtual Console capability.
Separating a logic (graphics) chip from memory results in narrow bandwidth.
eDRAM integrates DRAM with logic circuits in a single chip, which is an ideal configuration for graphic acceleration applications that require high data bandwidth. NEC has achieved excellent results in manufacturing such chips by integrating "metal-insulator-metal 2 (MIM2) stacked DRAM capacitors" in the company's standard CMOS process.
Embedding RAM is much better.
NEC first brought this MIM2 technology to market in 2005 on 90nm eDRAM. The company achieved this breakthrough via a number of advances, including "1) using a MIM structure for the electrodes in the DRAM cell to achieve lower resistance values and higher data processing speeds, 2) using cobalt-silicide (CoSi) DRAM cell transistors to increase driving performance, and 3) using zirconium-oxide (ZrO2) in the capacitance layer (ahead of other vendors) to increase capacitance of the unit area."
NEC is promising to press forward in developing their eDRAM technology to make the move from 90nm processed chips to 55nm in the near future. While the Wii will be making use of the 90nm technology, the potential for future manufacturing advances of the NEC supplied chips may eventually result in even more efficient and smaller chipsets for the Wii down the line.
NEC's roadmap towards 55nm eDRAM.
NEC also revealed that it has selected MoSys as the DRAM macro design partner for the "Wii devices," due to the fact that MoSys is quite familiar with implementing 1T-SRAM macros on NEC's eDRAM process. The 1T-SRAM technology is the product or more than six years of technical collaboration between Nintendo and MoSys. Previous generations of the technology were incorporated in the GameCube.
MoSys memory will be used as the main embedded memory on the Wii's graphics chip and in an "additional external memory chip." Genyo Takeda, Senior Managing Director and General Manager of Integrated Research and Development Division at Nintendo commented: "Designing the Wii console required an incredible list of breakthroughs in technology and innovation. The performance delivered by MoSys' 1T-SRAM technology is an important element of our solution. The graphic performance of Wii benefits from MoSys' ability to develop highly innovative and dependable embedded memory products."
According to MoSys, 1T-SRAM technology is the most advanced embedded memory technology in the world. Based upon a single transistor cell to achieve exceptional density, the technology is able to maintain the beneficial qualities of refresh-free interfacing and low latency random memory access cycle time that characterize the traditional six-transistor SRAM cell design.
The announcements confirm IGN's previous reports that the Wii would make use of 1T-SRAM both in an embedded and individual application. Our most up-to-date specs promise 16MB of eDRAM (integrated in NEC's LSI chips) and 88MB of 1T-SRAM (the "additional external memory chip"), for a total of 104MB of system RAM, not counting the allegedly accessible 512MB of Flash RAM or the ATI Hollywood GPU's on-board memory, which is said to amount to 3MB.
NEC certainly seems positive about the announcement, and well they should. The company has not reported profits for more than a year. On the strength of the expected demand for the Wii, however, NEC Electronics is now forecasting operating profits of $44 million for the year ending March 2007.
