Devices EFR32FG22 Series EFR32FG22C121 EFR32FG22C121 Silicon Labs Devices 4 EFR32FG22C121F256GM32 EFR32FG22C121 Cortex-M33 EFR32FG22C121F256GM40 EFR32FG22C121 Cortex-M33 EFR32FG22C121F512GM32 EFR32FG22C121 Cortex-M33 EFR32FG22C121F512GM40 EFR32FG22C121 Cortex-M33