Devices EFR32SG28 Series EFR32SG28 Series Silicon Labs Devices 4 EFR32SG28B320F1024IM48 EFR32SG28B320 Cortex-M33 EFR32SG28B320F1024IM68 EFR32SG28B320 Cortex-M33 EFR32SG28B322F1024IM48 EFR32SG28B322 Cortex-M33 EFR32SG28B322F1024IM68 EFR32SG28B322 Cortex-M33