NEC Electronics Corp has been slapped with an infringement suit by Enhanced Memory Systems Inc, alleging that NEC’s Virtual Channel Memory DRAM product violates a patent now owned by EMS. The small Colorado Springs-based company – which is a subsidiary of Ramtron International Corp – says that it had been reluctant to engage in patent litigation but that it felt compelled to protect the investment it made in developing what it says is the next-generation high performance DRAM. The patent in question protects the architecture of its EDRAM products that combine DRAM and SRAM technologies into one high-performance memory. EMS says it began shipping its high performance 4MB EDRAM product in 1992 and announced the development of an advanced 133 MHz synchronous EDRAM in November 1996. Patents were awarded to the company in 1997 and earlier this year covering the key architecture and method of operation for the products. The company has 12 more patent applications pending that relate to the technology and claims EDRAM manufacturing agreements with Siemens Semiconductors and IBM Electronics. It also says it is pursuing other strategic partnerships to advance its technology in the marketplace.