The lawsuit pits Rambus against memory chipmakers Hynix, Micron Technology and Nanya Technology, and the decision opens the door for Rambus to collect royalties of hundreds of millions of dollars perhaps even billions from its technology, which speeds the performance of memory chips used in a vast array of electronic devices.
Rambus says the jury verdict completes the case involving Hynix; it will now move for an injunction to prevent Hynix using Rambus technology in its chips.
Hynix, the world's No 2 memory chip maker, says it will appeal, as does Nanya in Taiwan.
Micron, the largest US memory chipmaker, was even more aggressive. It too said it would appeal, calling Rambus's patents "invalid" and "unenforceable".
Rambus makes most of its money by licensing patented chip designs created by its engineers and used widely in DRAM chips. The company had about US$180 million in revenue in 2007.
