In this episode of MCU Wars, Ritesh Tyagi and Chris Anderson compare two 32-bit microcontrollers—the RX100 from Renesas, and the STM32 from STMicroelectronics. We chose these two devices because of the increasing demand for 32-bit microcontrollers in a variety of industries. Which one reigns supreme?
*Optimized for Low-Power* According to Tyagi, Renesas has been “using a lot of proprietary technology to optimize the RX100 power consumption.” In order to do this, Renesas implemented a 130mm, low-leakage, low-power transistor flash process. “Compared to the RX600 or RX200 where we used their proprietary MONOS technology,” Tyagi explained, “we decided to use a completely different technology for the RX100.” Another differentiating factor is the redesign of the clock circuitry to offer a much faster wake-up. This allows the device to remain low-power in active and standby modes. The voltage regulator was built specifically for this device, offering very low power consumption. “Overall, there are a lot of different techniques and tricks that we employed to achieve a very low power standby current and active mode current,” Tyagi stated.
*The STM32 L1 Toolchain* When asked about the STM32 toolchain, Chris Anderson offered his preferences for ST products. Anderson explained, “ST offered a number of choices with quickstart guides for Embedded Workbench, but I settled on the Kiel Microvision 4.” Anderson stated that the Microvision had a number of example files that had all the source code needed to start tweaking in order to find something close to what he was trying to do. It also has a project manager compiler, an integrated debugger, and an abundance of example projects for dev kits of all the other major ARM vendors.
Getting Started the RX100 For the RX family, Renesas made a big company-wide push to launch the Eclipse- based IDE, called the e 2 studio. The RX100 will have the same toolchain based on the e 2 studio. Underneath that, Renesas offers a compiler as well as a compiler from IR and other third parties. “In fact,” Tyagi explained, “we are doing a pretty big joint promotion with International Rectifier where they start offering a 64K version of an IR workbench absolutely free.” The kit also comes with multiple sample projects and application examples. The board comes with a CD with a compiler and a debugger all within the kit. “I can guarantee,” Tyagi said, “that with the RX kit, you can be up and running within an hour.”
*Editor’s Pick* Overall, the RX100 by Renesas offered significant low-power advantages over the STM32. The RX RDK Development Kit also offered significant features over the ST Discovery Kit, made possible by Renesas’ many partnerships in on-board components.