Low Power 3.5G Mobile Handset Chip - NEC “M2″

NEC introduced the "M2" chip, an ARM1176JZF-S-based, low power 3.5G Mobile Handset LSI chip. The "M2" chip is one of the NEC’s Medity series of mobile handset solutions. "M2" is the successor to the "M1" chip (based on ARM926EJ-S ) introduced in 2006, renowned for 700-hour standby time. Besides the improvements in power consumption, the "M2" also reduce total number of external parts, by sharing the external memory used by the application processor and the DBB (digital baseband).

NEC’s "M2" mobile handset chip employs these technology:

• Reduction in active power consumption
  Dynamic frequency scaling technology reduces active power consumption by monitoring the bus traffic and automatically adjusting the system clock frequency. In addition, automatic hierarchical clock control technology monitors the macros and automatically stops a clock when a macro is not active, further reducing active power consumption.
• Reduction in leakage current due to internalized power switches
  On-chip power switches help reduce leakage current when the macro is not active. In addition, a Quick Recovery technology helps save leakage current and makes it convenient to power off the CPU frequently. This is enabled automatically by hardware. The internal state of the CPU is saved before it is powered down. When an interrupt occurs, the technology restores the internal state of the CPU and power without rebooting.
• Reduction in LCD control power consumption in system standby mode
  In standby mode, LCD Direct Path technology transfers data necessary for LCD display directly from the frame buffer to the LCD controller, bypassing the main bus, and thereby reducing standby power consumption.
• Reduction in leakage current due to back-bias technique
  For the high speed CPU and DSP, which rely on low-Vt transistors, back-bias technique maintains optimal threshold voltage and helps reduce leakage current. CPU and DSP speed can be optimized while leakage current is reduced, without leakage variation, by monitoring the timing of the ring oscillator.
• Reduction in leakage current due to Multi-Vt transistors
  By utilizing three different types of Vt transistors, the "M2" chip is able to achieve both high-speed operation and low leakage current. The High-Vt transistors are low-speed but also have low leakage current, making it ideal for the DBB, which is always on. On the other hand, the Low-Vt transistors have higher leakage current but also high speed performance, achieving 500MHz operating performance optimal for the application CPU and DSP.

"M1" and "M2" are the backbone of NEC’s Medity solution, which includes the following products and services:

• A chipset that includes a DBB and application processor, RFIC, and power IC
• Evaluation boards and reference design kits
• Software to drive the system LSI
• System integration services to port fundamental software and middleware
• Development tools for communications software and application software support

Samples of the "M2" chip are priced at $45. Volume production is scheduled to begin in October 2007.

NEC Electronics also has plan to release next gen Medity2, which will be based on the "M2" chip, at the end of 2007.

More info: NEC "M2" 3.5G Mobile Handset Chip