[14] REGULATORS: LDO mode at startup

This anomaly applies to IC Rev. Engineering A, build codes SICA-BAA.

Symptoms

The device is set to LDO mode.

Conditions

Startup from reset.

Consequences

LTE modem is certified to operate in DC/DC mode. The certifications are not valid if the LDO mode is used.

Workaround

Application software needs to set the regulators into DC/DC mode before starting up the modem. Set registers at startup as described below. For secure mode:
 
*((volatile uint32_t *)0x50004A38) = 1; 
For non-secure mode:
 
*((volatile uint32_t *)0x40004A38) = 1; 
NRF_REGULATORS->DCDCEN = 0x01.
Note: Workaround included as of MDK 8.21.0 and later releases.