Rambus- Security and LED joins Memory
March 2012, Santa Clara, CA - In a recent interview with Ely Tsern Chief technologist of Rambus’s Global Semiconductor Business Unit, we had the chance to discuss the new directions being addressed by Rambus. The conversation was prompted by visable omission of any Rambus papers in the DRAM session at ISSCC held in Feb 2012. Instead, they had several papers in the interface session dealing with serial links, SERDES and other high speed low power interfaces.
The theme for the papers and their technology direction for semiconductor unit is the highest performance per watt. The two papers submitted- papers 7.2 and 7.5 dealt with two of the common intergaces that are now growing in popularity and speed. Paper 7.2 discussed a single ended interface link achieving 16Gb/s at a power factor of 0.4mw/Gb/s . This single ended interface (near ground receiver) is the typical signal path seen in DDR3, DDR4 and GDDR5 memories. As GPUs are being used for high speed computing functions and are appearing multiple times int eh system architecture, the use of these interfaces is increasing and the need to reduce latency and signal integrity is also growing. Part of the low power specification was achieved by operating the block with a 1V supply.
Paper 7.5 discussed a 4.1pJ/b 16Gb/s coded differential bidirectional link. This is a typical backplane interface and is now moving to chip-to-chip and across board high speed interconnect. In the parallel implementation, the PHY is presented for chip to chip interconnect. For backplane applications the interface would be bundled with a high speed SERDES to transmit the data. The results presented were from low cost FR4 material.
As markets other than servers and core compute, these technologies are being migrated to mobile devices such as tablets, smart phones, and laptop/netbooks. The mobile space for using LRDIMM devices is expected to grow significantly with the release of windows 8 for the tablet, and this will further advance the mobile PC. The mobile business model is hampered at this time, by space and power. A tablet/mobile device has space for 2 devices in sockets, where a PC or server can use 16 devices. The attach rate for these memories is high per processor, but has a lot of platform variability.
To address being caught in this reduced attach rate bind, they are in the process of expanding their markets. They recently purchased Unity Semiconductor to enter the high density MRAM space for ultra low power. They are also working on new memory standards and advancing DDR3 and LPDDR into new markets.
They have also made an move into the security space with the purchase of CRI which is a cryptographic company that is entrenched in the smart card industry. They wil be be providing software and hardware solutions into this space. The company will be leveraging this technology and expanding further into the settop box and mobile platforms with the technology. The goal is to integrate features directly into thier memory and interface solutions.
Another new market area is their move into the LED and general/industrial lighting space. They have done a number of acquisitions and licensing programs in this area and are targeting the multi billion unit general lighting (i.e. bulbs and fixtures) market on both a retrofit and new installation basis. These products are very semiconductor and cost centric and are well targeted for the Rambus technology licensing models.