EFR32FG22 Flex Gecko Wireless SoCs Silicon Labs EFR32FG22 Flex Gecko Wireless SoCs are ideal for enabling energy-friendly proprietary protocol networking for IoT devices. The single-die solution combines a 38.4MHz Arm® Cortex® M33 with a high-performance 2.4GHz radio to provide an industry-leading, energy-efficient wireless SoC for IoT connected applications.