Renesas Technology to Release R8C/Mx Series of Flash MCUs with Extremely Low Power Consumption and Powerful On-Chip Peripheral Functions

The R8C/Mx Series is a new addition to the R8C Family of flash MCUs, which has an established track record based on low pin count and high performance. The new series combines extremely low power consumption and a low pin count. The first products to appear will be the R8C/M11A, with a 14-pin package, and the R8C/M12A, with a 20-pin package. They will comprise a total of six types with 18 products, and sample shipments are scheduled to begin in March 2010.

Through the new fabrication process and other enhancements, the current consumption during operation (active current) of the R8C/M11A and R8C/M12A is only 150 µA per 1 MHz, a reduction of approximately 60% from the 350 µA per 1 MHz of comparable earlier Renesas Technology products. This is ideal for battery powered compact electrical household appliances that require low power consumption.

In addition, the standby current is less than 1 µA, approximately half that of earlier Renesas Technology products, making R8C/Mx Series products suitable as sub-MCUs in larger systems with extensive standby time, such as consumer products and office equipment, where they can contribute to improved energy efficiency overall.

R8C/Mx Series MCUs are equipped with on-chip peripheral functions, including timers and comparators, required by compact electrical household appliances such as electric shavers, which require sensor detection and control functionality. The R8C/Mx has up to 6 powerful AD converters with 2.15us conversion time and two result registers. Two quick comparators at 100ns have compare output functions and can easily be connected to the 16-bit Timers. This makes it possible to handle in hardware processing previously done by the CPU using software, for example, using a comparator for direct control of a timer based on sensor input. Bypassing the CPU in this way increases flexibility and improves real-time performance. In addition, the 3 x 16-bit on-chip timers support three-phase pulse output, simplifying motor control.

All Mx devices are pin compatible and have several high current drive port pins as well as safety function, such as read back I/O pin. The on-chip peripheral I/O mapping controller enables reassignment of pin functions. This can help reduce development time by eliminating the need to make changes to the wiring board.

Data flash*1 is a special type of on-chip flash memory exclusive to Renesas Technology that is intended for storing data. It eliminates the need for external EEPROM (Electrically Erasable and Programmable Read Only Memory) for data storage. The data flash of R8C/Mx Series MCUs supports a reprogramming/erasing voltage of only 1.8 V rather than the 2.7 V of earlier Renesas Technology products. This is suitable for applications requiring low-voltage operation, such as battery-powered products that must store data when the power supply is cut off.

The R8C/M11A is the first Renesas Technology MCU to feature a 14-pin package suitable for compact electrical household appliances requiring low-pin-count packages. It is available in either a compact TSSOP measuring 4.4 mm × 5 mm or an easy-to-mount DIP package. The 20-pin R8C/M12A is also available in either an LSSOP measuring 4.4 mm × 6.5 mm or a DIP package. Customers can choose the package that best matches the product under development, with options available that help reduce wiring board size and lower system cost.

The R8C/Mx Series is built around the R8C CPU core and delivers high-performance, powerful functionality, and excellent flexibility. The R8C is a 16-bit CPU, but the CPU and peripheral functions are linked by an 8-bit bus. Its maximum operating frequency is 20 MHz, and its wide operating voltage range extends from 1.8 V to 5.5 V. The package is compact and has a low pin count, and the data flash can be reprogrammed, erased, and read using a voltage down to 1.8 V. The many on-chip peripheral functions include a high-speed on-chip oscillator, with two pre-calibrated values, a low speed on-chip oscillator, power-on reset circuit,*2 and a low-voltage detection circuit*3 (two on-chip circuits supporting two and eight setting levels, respectively). This reduces the number of external devices required, such as EEPROM, oscillators, reset chips, and pull-up resistors, contributing to reduced system cost and smaller wiring board size.

The E8a emulator, an on-chip debugger that uses a single-pin interface, will be offered as a development environment for the MCU. Since only a single pin is needed for connection, all of the I/O pins can be used during debugging, enabling efficient program development. The E8a emulator functions not only as an emulator, but can also be used as a flash memory programmer.

The future evolution of the R8C Family will include products with even smaller packages, lower power consumption, and on-chip functions selected for specific fields. Renesas Technology will continue to extend its MCU lineup in response to evolving market needs, contributing to the development of products that are more compact, operate on lower voltage, and consume less power.