SAN JOSE -- Hitachi Ltd. and Rambus Inc. today announced a settlement to a six-month legal dispute over patent claims for high-speed memory interfaces in synchronous DRAMs and controllers interfacing to those devices.

Under the agreement, Hitachi will pay Rambus an up-front settlement fee as well as quarterly royalty payments for use of patented interface technologies in high-speed SDRAMs, double data rate (DDR) SDRAMs, and controllers that interface to those memories. All pending litigation will now be terminated, subject to court and government agency approvals, according to the two companies.

Rambus said royalty payments for interfaces on DDR SDRAMs and controllers will be at a higher rate than those collected for Rambus DRAMs made by Hitachi. Rambus has been promoting its own high-speed architecture as a competing memory approach to DDR DRAMs.

"We believe our Rambus memory interface is the best solution for the majority of the market," said Geoff Tate, CEO of the Mountain View, Calif.-based company. "Developing and marketing the Rambus memory interface has been and remains our top priority, but we are willing to license our IP intellectual property for other memory interface solutions as well."

The specific terms of the new license agreement were not released by Hitachi or Rambus.

The settlement comes one week after Rambus announced a new licensing pact with Toshiba Ltd. to extend its use of patents for high-speed interfaces in SDRAMs and DDR memories (see June 16 story). Under that agreement, Toshiba also agreed to pay higher royalties for patented interfaces on SDRAMs, DDR memories and chips that did not conform to the Rambus DRAM architecture.

A spokeswoman for Hitachi in the U.S. said the Toshiba agreement was not a factor in Hitachi's settlement and new licensing arrangement with Rambus. Hitachi also is not agreeing with Rambus' claim that it was violating the high-speed interface patents in SDRAMs and microprocessors, she added.

Earlier this year, Mountain View, Calif.-based Rambus accused Hitachi of violating its patents on clock timing techniques in SDRAMs and microprocessors (see Jan. 18 story). Rambus then took its case to the U.S. International Trade Commission (ITC), seeking a ban on imports of Hitachi processors and memories as well as electronic games from Sega Enterprise Ltd. using those chips (see March 23 story). Rambus also filed suit against Hitachi in Germany.

Hitachi denied Rambus' allegations and filed counterclaims in the dispute. Hitachi also petitioned the ITC to include other Japanese memory companies in its investigation of Rambus' complaint.

But now the fight has been dropped by both sides, according to Hitachi. "I believe that the early settlement of these lawsuits ensures further growth of Hitachi's semiconductor business," said Tadashi Ishibashi, president and CEO of Hitachi's Semiconductor & Integrated Circuits group. "In addition, Hitachi wishes to re-establish the good business relationship that had existed between the companies since 1992, when the original Hitachi-Rambus license was executed," added Ishibashi.

--Additional reporting by Jack Robertson