Cryptographic flow

    
    /* Enable CRYPTOCELL subsystem */
    NRF_CRYPTOCELL->ENABLE = CRYPTOCELL_ENABLE_ENABLE_Enabled;

    /* Enable engine clock */
    NRF_CC_RNG->RNG_CLK = CC_RNG_RNG_CLK_ENABLE_Enable;

    /* Reset engine */
    NRF_CC_RNG->RNG_SW_RESET = CC_RNG_RNG_SW_RESET_RESET_Enable;

    /* Configure sampling rate between consecutive bits */
    do { 
        NRF_CC_RNG->RNG_CLK = CC_RNG_RNG_CLK_ENABLE_Enable;     
        NRF_CC_RNG->SAMPLE_CNT = NRF_FICR->TRNG90B.ROSC1;
    } while ( NRF_CC_RNG->SAMPLE_CNT != NRF_FICR->TRNG90B.ROSC1 );

    /* Configure ROSC length */
    NRF_CC_RNG->TRNG_CONFIG = CC_RNG_TRNG_CONFIG_ROSC_LEN_ROSC1;

    /* Enable noise source */
    NRF_CC_RNG->NOISE_SOURCE = CC_RNG_NOISE_SOURCE_ENABLE_Enabled;

    /* Wait for random data to be sampled */
    while ((NRF_CC_RNG->RNG_ISR & CC_RNG_RNG_ISR_EHR_VALID_INT_Msk) == 0) {}

    /* 192 bits of random data now available in
       NRF_CC_RNG->EHR_DATA[0] to NRF_CC_RNG->EHR_DATA[5] */