Mindful that the best defence is often a good offence, Micron Technology has filed suit against Rambus, slapping the litigious firm with an antitrust suit of its own. The suit, filed in United States District Court in Delaware, asserts that Rambus violated federal antitrust laws and alleges that some Rambus patents are invalid or unenforceable. Micron has also accused Rambus of breach of contract and fraud. The suit, which challenges Rambus' claims to rights to certain synchronous dynamic RAM (SDRAM) technologies, has the potential to damage Rambus, because all its revenue comes from licensing memory technology. Along with other requests, Micron is asking the court to declare that Rambus has monopolised the US market for SDRAM and to prevent the company from continuing to do so in the future. Micron also asks that the court prevent Rambus from enforcing the patents listed in the suit and, at the same time, award Micron a royalty-free licence to them. Micron also seeks compensatory damages, attorney's fees and court costs. Rambus issued a statement Tuesday afternoon, after reviewing a copy of the suit: "Rambus initiated negotiations with Micron to license Rambus' intellectual property for use in SDRAM and DDR (double data rate) SDRAMs. Rather than negotiate, Micron chose to litigate. Rambus is preparing a response to Micron's allegations. Rambus expects to prevail in this litigation and to be fairly compensated for the use of its IP." The price of both companies' stocks fell on the news. Rambus has sought to use the legal system to its advantage, as well. The company, in enforce patent claims, sued Hitachi -- with whom a settlement was reached -- and Infineon. The Infineon suit is still in progress. Micron's manoeuvres clearly aim to head Rambus off at the pass. "What our complaint alleges is that Rambus violated federal antitrust law and that some of their patents are invalid or unenforceable," said Micron spokesman Grant Jones. "We really think that based on their [Rambus'] prior actions, that this is the best course of action." A copy of the suit reviewed by ZDNet News on Tuesday says that on 18 August, just days after Rambus filed suit against Infineon, Micron's chief executive, Steven Appleton, received an email from a Rambus representative requesting a "meeting" next month to discuss the patents, presumably Rambus' SDRAM claims. Micron asserts its belief that this "notice" was similar to ones that Rambus had sent to Infineon and other SDRAM manufacturers, meaning that Rambus would present non-negotiable licence terms for the Rambus patents highlighted in the suit. Micron argues that Rambus violated antitrust laws by applying for patents on SDRAM technologies without first informing the Joint Electronic Device Engineering Council (Jedec). The Jedec, as it is called, is a standard-setting body for the semiconductor industry. It is responsible for setting standards for things such as SDRAM. Micron argues that by joining the Jedec, Rambus implicitly agreed to inform all the members of association about new patents that might pertain to SDRAM. It is these patents that Micron said are invalid or unenforceable. Micron also claims that joining the Jedec, as Rambus did, also requires members to license their patents to other Jedec members either without charge or under "reasonable and non-discriminatory terms", if those patents are used as part of a standard. "Rambus subverted the open standards process so that it could gain monopoly control of the Synchronous DRAM technology and Synchronous DRAM markets," the suit claims. Micron is asking the court to either prevent Rambus from asserting the patents implicated, or grant Micron a royalty-free licence to them. Micron also claims that its backing of double data rate DRAM (DDR DRAM) has also made it a Rambus target. DDR DRAM is the successor to the SDRAM technology and a competitor to the Rambus direct RAM (RDRAM) memory technology. "Micron is a strong proponent of DDR DRAM memory products. Rambus has indicated that it views DDR DRAMs as a competitive threat to its RDRAM technology. "Rambus has stated that it would not dispute that it was charging higher royalties for DDR DRAMs to head off a potential rival to RDRAM. Micron's endorsement of DDR DRAMs makes it an even more likely target of a patent lawsuit by Rambus," the suit said. Rambus is also expected to file a response to the suit within about three weeks, Micron officials said. From there, dates for discovery, or gathering of evidence, as well as a trial will be set, assuming the suit is not settled first. "We expect it to be a rather lengthy process," Jones said. What do you think? Tell the Mailroom. And read what others have said.