how to program the code in software to enable flash read protection

[chenwenbin]

config flash read  protection in code 

[Simonr]

I think this is because you need a system reset in order to "activate" the readback protection. Either, set the following const in outside any function in your main file (this won't require a system reset for the readback protection to turn on:

const uint32_t approtect_set __attribute__((used,at(0x10001208))) = 0xFFFFFF00;

Or, you can add this snippet at I.E. the start of your main() loop, which will set readback protection and trigger a system reset to enable the readback protection.

void nrf_nvmc_write_word(uint32_t address, uint32_t value)
{
    // Enable write.
    NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen;
    __ISB();
    __DSB();

    *(uint32_t*)address = value;
    while (NRF_NVMC->READY == NVMC_READY_READY_Busy) {;}

    NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren;
    __ISB();
    __DSB();
}

int main(void)
{
    nrf_delay_ms(1000);
    if (NRF_UICR->APPROTECT == 0xFFFFFFFF)
    {
        nrf_nvmc_write_word((uint32_t)&(NRF_UICR->APPROTECT), 0xFFFFFF00);
        
        NVIC_SystemReset();
    }    

Best regards,

Simon

[chenwenbin]

thanks!  const uint32_t approtect_set __attribute__((used,at(0x10001208))) = 0xFFFFFF00;  the code is OK,   it means that my code is save ,  can not be readback  anyway