Target family usage notes

This section documents usage notes for certain target types.

Nordic Semiconductor

nRF51 family

See SoftDevice for notes about handling firmware containing SoftDevice images.

nRF52 family

See SoftDevice for notes about handling firmware containing SoftDevice images.

Unlocking of flash security, also called APPROTECT, is supported. For more, see the security and protection documentation.

SoftDevice

The nRF51 and nRF52 series have support for so-called “SoftDevice” firmware, which implements Nordic’s Bluetooth LE or other wireless protocol API. When firmware containing a SoftDevice is loaded, the SoftDevice region of flash is locked. In order to reprogram the flash sectors containing the SoftDevice image, a mass erase must first be performed. This can potentially cause issues with flash programming if one is not aware of this requirement.

For a development workflow with firmware using a SoftDevice, no extra steps are required.

PyOCD will by default scan flash sectors when programming flash in order to only erase and program sectors whose contents are changing. Since normally the SoftDevice sectors do not change during development, pyOCD will skip over these sectors.

In addition, a chip erased performed with a SoftDevice in flash will erase only the non-SoftDevice sectors. For example, running pyocd erase --chip on such a device will leave the SoftDevice intact and erase all other sectors.

However, any case where the SoftDevice sectors are being erased requires a prior mass erase. This includes changing the SoftDevice variant or version, as well as switching to firmware that doesn’t include a SoftDevice. Mass erase is a separate operation. It mostly functions like a chip erase, but can also be used to unlock devices that have APPROTECT enabled.

To perform a mass erase:

pyocd erase --mass

NXP

Kinetis family

Unlocking of flash security is supported for all Kinetis targets. For more, see the security and protection documentation.