LSI and STMicroelectronics did not infringe on patents claimed by Rambus, according to a ruling by the U.S. International Trade Commission on Wednesday.

In its notice, the ITC affirmed the initial determination of Administrative Law Judge (ALJ) Theodore R. Essex that there was no violation of Section 337 of the Tariff Act of 1930 with respect to the asserted patents. The Commission also reversed the ALJ?s determinations that Rambus demonstrated the existence of a domestic industry, that certain asserted Dally claims were invalid, and that those claims were infringed.

Rambus claimed the chip makers had violated patents related to chipset communication and controlling of memory and digital transmitters.

ITC said some patents were unenforceable, while Rambus prove other infringement claims against other companies.

Rambus is evaluating the next steps, which may include an appeal, said Thomas Lavelle, senior vice president and general counsel at Rambus.

"We are evaluating our next steps in this matter, which may include a possible appeal to the Federal Circuit. We remain steadfast in our commitment to protecting our patented inventions from unlicensed use," said Thomas Lavelle, senior vice president and general counsel at Rambus.

In December 2010, Rambus filed a complaint with the ITC requesting an investigation pertaining to certain products from Respondents Broadcom, Freescale, LSI Logic, MediaTek, NVIDIA and ST Microelectronics. The complaint sought an exclusion order barring the importation, sale for importation and sale after importation of products that infringe certain Rambus patents from the Dally and Barth families. For the Dally patents, the accused semiconductor products include those that incorporate PCI Express, certain Serial ATA, certain Serial Attached SCSI (SAS) and DisplayPort interfaces. In the case of the Barth patents, the accused semiconductor products include those that incorporate DDR, DDR2, DDR3, mobile DDR, LPDDR, LPDDR2, and GDDR3 memory controllers. Accused semiconductor products in the complaint include graphics processors, media processors, communications processors, chip sets and other logic integrated circuits (ICs).

An evidentiary hearing was held before the ALJ in October 2011. On March 2, 2012, the ALJ issued an initial determination finding the asserted patents infringed by the Respondents but invalid over prior art. The ALJ also found the asserted Barth patents to be unenforceable. Since the investigation was instituted, Rambus has signed settlement and patent license agreements with former Respondents Broadcom, Freescale, MediaTek and NVIDIA.