STMicroelectronics, 32bit ARM 32-bit Cortex-M0, ARM Cortex M0 Microcontroller, 826 → 958MHz, 256 kbyte Flash,

The STMicroelectronics STM32WL33xx is a high performance ultra-low power wireless application processor, intended for RF wireless applications in the sub-1 GHz band. It is designed to operate in both the license-free ISM and SRD frequency bands such as 433, 868, and 915 MHz. It adopts a single-core architecture embedding an Arm® 32-bit Cortex®-M0+ CPU that can operate up to 64 MHz. It integrates high-speed and flexible memory types: up to 256 Kbyte flash memory, and up to 32 Kbyte RAM, onetime programmable (OTP) memory area of 1 Kbyte. Direct data transfer between memory and peripherals and from memory-to-memory is supported by seven DMA channels with fully-flexible channel mapping by the DMAMUX peripheral.

Ultra-low power sub-1GHz wireless system-on-chip
Radio frequency bands 159 to 185 MHz and 413 to 479 MHz and 826 to 958 MHz
Air data rate from 0.1 to 600 kbit/s
Programmable TX power up to +20dBm
Suitable for worldwide certifications Europe ETSI EN 300 220 and category 1 compliant and ETSI EN 303 131
US FCC part 15 and part 90
Japan ARIB STD T67 and T108
Low power autonomous wakeup receiver and featurings
Ultra low power architecture
Ultra low power on reset and power down