The release of the R8C/Mx Series of low-pin-count MCUs has been announced by
Renesas Technology Europe. They feature on-chip flash memory (flash MCUs)
offering power consumption among the lowest in the industry and improved
functions including timers for applications requiring low power consumption,
such as electric shavers, electric toothbrushes, and other compact
electrical household appliances.
The R8C/Mx Series is a new addition to the established R8C family of flash
MCUs. 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 150µA per 1MHz, a reduction of approximately 60% from the 350µA per
1MHz of comparable earlier Renesas Technology products. This is seen as
ideal for battery powered compact electrical household appliances that
require low power consumption.
In addition, the standby current is less than 1µA, 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 six 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 flash1 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 1.8V rather than the 2.7V 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 4.4mm × 5mm or
an easy-to-mount DIP package. The 20-pin R8C/M12A is also available in
either an LSSOP measuring 4.4mm × 6.5mm 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 20MHz, and its wide operating
voltage range extends from 1.8V to 5.5V. 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 1.8V. 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, and a low-voltage detection
circuit (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, says the company.
