Hitachi to enter DRAM-on-ASIC club

Electronic News, July 21, 1997 by Peter Brown

Brisbane, Calif.--Hitachi America will today introduce its first ASIC with embedded DRAM for the U.S. market, thereby joining a growing list of ASIC vendors offering embedded DRAM. Hitachi, which will offer up to 140 megabits of DRAM memory on a single chip, also gave Electonic News a preview of what it intends to put on future devices and said it will today unveil a roadmap for ASIC products that includes embedded flash ASICs and combination ASICs featuring both DRAM and flash memory.

According to King Ou, Hitachi's ASIC product marketing manager, Hitachi has been embedding DRAM internally for two years and has been selling them to limited OEMs in Japan; however, this is the company's first venture to bring the technology to the U.S. Dubbed the HG73M, the embedded DRAM ASIC series is the initial step of Hitachi's plans to become a dominant player in the U.S. ASIC industry.

"We are not known in the U.S. for our ASIC capability and this is our first stride toward making that presence more known," said Mr. Ou. "It's kind of a Catch 22 with ASIC customers because you have these people who have existing relationships with vendors and it's very difficult to penetrate those relationships but I think with our philosophy and good design centers we will be able to expand our presence rather rapidly."

Hitachi will offer the HG73M as standard cell devices only, and has no plans to support gate array technology in future U.S. devices. However, Hitachi will utilize its deep submicron processes for gate arrays domestically in Japan and parts of Asia. Mr. Ou did reveal the company is considering bringing cell-based array (CBA) ASICs--based on Silicon Architects of Synopsys' architecture--to the U.S. Hitachi licensed the CBA architecture last year for use in the Japanese market (EN, The Circuit, June 24, 1996).

"Right now we are looking at how to maximize our strengths with embedding highly complex designs," said Mr. Ou. "If we were going to use gate arrays it would be almost a step back from what our plans are. CBA is something that may enable us to differentiate our product line while keeping it highly complex."

The HG73M is targeted at high-end graphics, networking, drive controls, CD-ROM type controllers and other personal access applications. A Hitachi HG73M standard cell ASIC with 200,000 gates and 16M of embedded DRAM is priced approximately at $45. Hitachi said design starts for the custom devices are available now.

The HG73M ASIC series also features Hitachi's proprietary Micro Module architecture that allows designers to configure the size of each embedded DRAM module from 1M to 4M. Multiple modules can be implemented on the same silicon to provide a maximum of 140M of DRAM if the ASIC is entirely composed of memory. The memory is based on Hitachi's stack manufacturing process that allows these multiple modules to be integrated onto one ASIC.

The HG73M uses a 0.28-micron DRAM process that is merged with a 0.35-micron logic process to enable the embedded DRAM ASICs. The HG73M features a maximum density of 5 million raw gates, clock speed of 150MHz on the logic side and 100MHz on the memory side as well as an operating voltage of 3.3V with 5V tolerant I/Os.

Meanwhile, revealing portions of its roadmap, Hitachi said it has plans to integrate flash memory with logic. Hitachi said this type of technology, manufactured on a 0.25-micron process, would be applicable in the automotive industry for emission controls and other automotive functions that demand reconfigurability.

"We already have the capability to mix logic and flash together on one chip and now it all depends on market demand for this type of product," said Mr. Ou. "Right now from our customer base we have heard this might have a possibility of coming to production in the near future but it takes a while for people to learn and adapt to using this type of technology."

Mr. Ou said that most flash users require a large amount of flash memory and a flash ASIC would have a far less amount of memory on-board than designers are accustomed to. So applications that require small amounts of non-violtile reconfigurable memory would be the only way for this technology to proliferate.

Hitachi's planned next generation of ASICs will have the ability to support DRAM, flash and logic on a single chip as well as microprocessor functionality. Mr. Ou said Hitachi has no time frame as to when this next generation part may be in production.