
Renesas configures MCU family around industrial/consumer designs
With 1.8V to 5.5V supply, the RX230 Group is aimed at applications that require high processing performance in environments with low current supply capacity, as well as the robustness needed in home appliance applications.
Compared to the existing RX231 Group, the RX230 is optimised with regard to embedded flash size and feature. This covers the requirements of cost-sensitive industrial and consumer applications that do not require USB nor CAN interfaces, can fit their code in 256 kB flash or less, and need a a maximum of 32 kB embedded RAM.
The RX230 Group can handle high processing loads, such as eliminating noise from digital signals and performing floating-point calculations, by using Renesas’ powerful 32-bit RXv2 CPU core with DSP/FPU operation capabilities. System power consumption is not only reduced by applying the latest Renesas process technologies, but also by reducing the CPU frequency and boosting the processing speed at the same time. The RXv2 CPU core as implemented on the RX230 achieves a performance benchmark score of 4.16 CoreMark/MHz, which Renesas says is leading edge in its class. RX230 achieves power performances in standby of 0.8 μA, which enables system manufacturers to extend system operation on battery power.
Operating speeds is up to 54 MHz, with an approximately fourfold increase in DSP performance and sixfold in FPU performance. As a result, the new MCUs significantly reduce the time required for high-processing load tasks such as digital filtering. At 0.8 µA in standby mode the contents of both SRAM and CPU registers are retained. The RX230 Group can recover from standby mode in a minimum of 5 µsec, which makes it possible to reduce current loss during the recovery and allow the application to react quickly to external events. Applications can be executed from flash after this time, and analogue functions, such as the analogue-to-digital converter, are available for use.
The RX230 Group also supports an additional low power timer (LPT), which only consumes an additional 0.4 µA and allows the system manufacturer to program the device to wake up from the low power modes with a very wide range of possible timings, minimising current consumption in many different applications.
The RX230 Group provides capacitive touch sensor capabilities equipped with Renesas’ second-generation capacitive touch technology. Up to 24 touch keys in a 100-pin package and down to 6 touch keys in 48-pin package are provided for a self-capacitance mode operation. Using the mutual capacitance mode, the RX230 MCUs can support up to 64 keys, and combines high sensitivity with a high level of noise tolerance. The RX230 detects touches even when the panel is wet or when the operator is wearing gloves, which creates highly flexible user interfaces in terms of usage environment and device design.
The MCUs offer hardware-based safety features for UL and IEC60730, including self-diagnostic and disconnect-detection monitoring for the on-chip A/D converter; a clock frequency accuracy measurement circuit; an independent watchdog timer, and a built-in hardware memory test to spot anomalies in the internal RAM. Operation is from a single 1.8V to 5.5V power supply, which allows system manufacturers to design robust applications and minimises their concerns about the signal-to-noise ratio. Reprogramming and erasing of the flash memory is enabled over the whole supply voltage range, which ensures an easy and cost optimised application design. The broadly scalable power supply concept therefore ensures that the RX230 is an ideal fit for home appliance and industrial application requirements.
Renesas; www.renesas.com/products/mpumcu/rx/rx200/rx231/index.jsp
