UniRAM Technology said similarities between its technology and that used by Monolithic System Technology (MoSys) was evidence its rival improperly acquired trade secrets from Taiwan Semiconductor Manufacturing Company (TSMC). UniRAM also found it curious the two United States chip rivals had similar road maps for new product development, despite UniRAM keeping its plans a secret. 'Since 1998, all of the significant technology 'developments' made by MoSys followed, step by step, the road maps UniRAM had earlier provided to TSMC,' the company said in its patent infringement suit, filed last week in California. UniRAM claims MoSys has earned US$50 million in revenue as a result of infringement of its patents and is seeking triple damages. TSMC, the world's largest chipmaker, has not been named as a defendant. According to the suit, UniRAM and TSMC signed non-disclosure agreements in 1996, 1999 and 2000. The US chipmaker was working on methods to manufacture memory circuits using logic fabrication processes. This is desirable because combining logic and memory on a single chip saves space and is more efficient. Under their agreement, TSMC was to receive normal foundry fees in exchange for manufacturing chips for UniRAM. In the late 1990s, TSMC began working with MoSys, according to UniRAM. MoSys gave TSMC 5 per cent of its stock in 1996 as payment for manufacturing services; this was reduced to 2 per cent after MoSys went public in 2001. In 1998, MoSys released a chip which also used a logic fabrication process - a development which caught UniRAM by surprise. UniRAM says the chip resembled its own in other ways, such as both included error correction circuitry. It said its rival's mimicry of its technology and business plans could not be explained by coincidence. 'UniRAM is informed and believes ... that MoSys acquired UniRAM's trade secrets from TSMC,' the company said. MoSys has denied the charges, while a TSMC spokesman said he had not seen the suit.