Renesas Technology believes the need for intelligent motor control in new types of energy-efficient systems will push the adoption of 32-bit microcontrollers for motor drive circuits.
Energy-saving motor controller design has been important in the Japanese market for some years and now it is happening 
in Europe, according to Terukazu Watanabe, chief engineer in the MCU business at Renesas.
A 32-bit MCU with a real-time operating system and comms interface support can be used to run energy-saving algorithms which can improve the efficiency of the motor.
The 
SH7142F microcontroller integrates the company’s MONOS flash which brings the benefit of deterministic 80MHz zero-wait operation yielding over 100 Dhrystone MIPS CPU performance. The access time is 12.5ns.
“This means an 80MHz CPU can be run single cycle out of flash memory without any tricks,” said Ian Hall, applications engineer in the industrial group at Renesas.
The MCU also has two timers each capable of driving a motor, and two 12-bit fast ADCs for measuring the phase currents and also provides for three sample and hold circuits in each ADC. “The conversion time is as fast as 1.25µs,” said Hall.
The SH-2 core also brings 16 registers and a multiply accumulate unit for running DSP algorithms.
With the industrial market in mind it also has two CAN modules. A bus state controller allows for an 8-bit external bus for the connection to external peripherals such as USB or Ethernet.
The SH7142F line-up includes variants with 512kbyte or 256kbyte of flash, with either 16kbyte or 12kbyte of RAM and includes both 80MHz or 64MHz options.
Renesas is a year into a programme aimed at increasing its share of the 32-bit MCU market in Europe. It currently has a 12 per cent market share and it is aiming for 30 per cent by 2012.