This anomaly applies to IC Rev. Engineering A, build codes QKAA-AB0.
Application
Reset value of HFCLKCTRL is invalid.
Always.
Application core has lower performance.
*((volatile uint32_t *)0x50039530ul) = 0xBEEF0044ul;
NRF_CLOCK_S->HFCLKCTRL = CLOCK_HFCLKCTRL_HCLK_Div2 << CLOCK_HFCLKCTRL_HCLK_Pos;