TOKYO After years of shying away from licensing processor cores from third parties, Mitsubishi Electric Corp. is planning to add synthesizable versions of the 32-bit RISC core from ARM Ltd. and a 16-bit digital signal processor core from DSP Group Inc. in an apparent move to sell more silicon to cellular phone manufacturers.
It is still unclear whether Mitsubishi has licensed the cores from ARM Ltd. (Cambridge, England) and the DSP Group (Santa Clara, Calif.), but a recent presentation outlining the company's semiconductor operations showed that the two cores are under development. It has not been disclosed when they will be integrated into Mitsubishi products.
The ARM7-TDMI-S is a 32-bit RISC core that incorporates the 16-bit Thumb instruction set extensions. It is software compatible with the ARM7TDMI core, which is widely used in cell phones. Because it is synthesizable, the core can be readily integrated and tuned to a semiconductor maker's manufacturing process.
National Semiconductor Corp. is the only company to have announced its licensing of that particular ARM intellectual property (IP) core, but Mitsubishi appears to be doing the same. "It's part of the IP library, but it's too early to say what the details are," a Mitsubishi spokesman here said. "There will probably be an announcement in the future on the topic."
In addition, Mitsubishi has added to its IP library the TeakLite DSP core. Developed by DSP Group, TeakLite is a synthesizable 16-bit fixed-point general-purpose core. Like the ARM7, it is designed for low-power applications like cellular phones, modems and disk drive controllers. It is binary-code compatible with DSP Group's Oak DSP, and is also backward compatible with the company's Pine DSP.
Though Mitsubishi has not explicitly stated it will target cellular phones with these new cores, the devices lend themselves to the rapid development of devices for portable applications. The Mitsubishi spokesman sai d the company is picking up more business from cellular phone makers.
A large portion of Mitsubishi's sales to this market come from SRAM and flash memory sales. Because heavy demand has helped create a supply crunch for flash memory, Mitsubishi is planning to boost its investment at its Kumamoto factory to increase production of its 16-Mbit DiNOR flash devices from 5 million units per month to 10 million units per month by the third quarter of 2000.
Mitsubishi is also developing a baseband controller based on Bluetooth, a wireless interface standard that is expected to be widely adopted in wireless handsets. Earlier this week, Philips Semiconductors and Ericsson Mobile Communications agreed to develop and produce Bluetooth wireless interface chip sets, and STMicroelectronics also said it would use Ericsson's Bluetooth core to develop Bluetooth ICs.
Mitsubishi has considered licens ing some form of the ARM core for more than a year, but until now has exclusively offered its own proprietary devices, such as the M16C and M32R families. MCUs account for about $1.2 billion or 26 percent of Mitsubishi's semiconductor sales, or more than any other single type of semiconductor it sells. Citing Dataquest Inc. figures, Mitsubishi claims to be the biggest supplier of 16-bit devices in the world, and the third largest supplier of MCUs overall.
The company also outlined plans to continue developing its M16C and M32 families. Along with more general performance improvements, the 16-bit family will have smaller program sizes and increased communications functions. The M32R family will integrate more embedded flash and DRAM, as well as a 128-bit bus internal bus now under development, according to Mitsubishi.