EFM32 Gecko Starter Kit board
Advanced System Monitoring
Energy Micro has always tried to better ARM's architecture by delivering a more power efficient system than its competition. The ARM Cortex-M3 architecture is the basis for its Gecko line (see Power Sipping Gecko) of low power, flash microcontrollers.
One way to check out the Gecko line is with the EFM32 Gecko Starter Kit board (Fig. 1). I found it inside the box along with a USB cable, a cute Gecko keychain and a copy of IAR's Embedded Workbench. It is also possible to install software from Keil, Code Sourcery and Rowly Associates. There are additional source code files, examples, etc. on Energy Micro's site. Full versions of these products will cost more but they provide enough support (32 Kbytes of code) to evaluate the system. I downloaded Energy Micro's Simplicity Studio. Simplicity Studio (Fig. 2) is an IDE that provides access to online documentation and app notes.
The $69 kit has board that provides access to all the micro's pins although the headers are not soldered in. It has an on-board SEGGER J-Link USB-based debugger that I found very convenient although you can plug in an external JTAG hardware debugger as well. The pins to the right provide support for optional plug-in modules. The LCD screen has 160 segments. There are two user defined buttons as well as a small slider touchpad supported by Touch Gecko software.
The board has a 32MHz EFM32G890 microcontroller with 32 Kbytes of flash and 8 Kbytes for SRAM. It has the Cortex-M3's memory protection unit. It includes DMA support, AES hardware acceleration plus a host of regular and very low power peripherals like the pair of low energy UARTs. Many of these peripherals can operate in standalone mode so the processor can remain in sleep mode.
The system is easy to get running and the software provides everything I needed to exercise the chip. The neat feature of the system is the Advanced System Monitoring (AEM) system. This uses the LCD screen to provide status information about the system's power consumption.
As with most low cost kits, most documentation is online or on the CD. The user manual provided info on the AEM and board operation in general. It did a better job than most describing how to install and test the system as well as where files were located for the board support package (BSP). Full schematics were included as well.
The optional battery support let me program the system and check it out in a standalone fashion although I didn't get a chance to connect it to much more than a logic analyzer. The power monitoring is definitely handy and may be sufficient for some basic application testing. Others may need to move to the $299 EFM32 Development Kit that has more patch space and a graphical LCD display for even more advanced AEM support.