How do I write directly to regiters in Mbed (set the GPIO voltage to 3.3V)

  1. I would like to set the output of my GPIOs in my nRF52840 to 3.3V instead of the default 1.8V.
  2. I have found a register called REGOUT0 that needs a value of 5 to be set.
  3. I also found a structure called NRF_UICR_Type containing the
    typedef struct {
    __IO uint32_t UNUSED0;
    __IO uint32_t UNUSED1;
    __IO uint32_t UNUSED2;
    __I uint32_t RESERVED0;
    __IO uint32_t UNUSED3;
    __IO uint32_t NRFFW[15];
    __IO uint32_t NRFHW[12];
    __IO uint32_t CUSTOMER[32];
    __I uint32_t RESERVED1[64];
    __IO uint32_t PSELRESET[2];
    __IO uint32_t APPROTECT;
    __IO uint32_t NFCPINS;

__IO uint32_t DEBUGCTRL;
__I uint32_t RESERVED2[59];
__IO uint32_t DCDCDRIVE0;

__IO uint32_t REGOUT0;

} NRF_UICR_Type;

I just don’t know where to read and write the structure!!!

Can anyone shed some light on this??