Rambus has filed a new patent infringement lawsuit against Micron, in the two companies ongoing legal battles.

The two companies have been in dispute since 2000, but the case was stayed by the court in 2002 pending a related appeals court decision. Now, with the case proceeding, Rambus has filed new claims that cover Micron's newer DDR2 and GDDR products.

Rambus designs technology that lets chips communicate with each other, but it is increasingly becoming known as the company in the middle of a mass of legal action in the memory industry.

It maintains that it holds patents to technology found in SDRAM memory chips used by the majority of the world's PCs. Micron is one of several companies, including Hynix, Samsung and Infineon Technologies that Rambus has sued as a result.

Last year the Infineon case was settled with Infineon agreeing to pay Rambus as much as $150 million in licensing fees.