ref:
https://docs.nordicsemi.com/bundle/sdk_nrf5_v17.1.0/page/index.html
<nRF5 SDK v17.1.0: Introduction>
The following toolchains/devices have been used for testing and verification:
- ARM: MDK-ARM version 5.25
- GCC: GCC ARM Embedded 9.2020-q2.major
- IAR: IAR Workbench 7.80.4
- SES: SES 5.42a