Device is secure

[vimalprasath]

I have custom Board with K64 MCU embedded in it.when i try to flash the code via MCUXpresso and Multilink Debugger.Im getting this error "Device is secure .Erase to unsecure" 
How do i solve this issue?

[jingpan]

Hi,

Please select yes to unsecure the chip.

In Flash address 0x40c is the Flash security byte. If this byte is changed to a error value, you'll see it. This value is set in startup_mk64fxxx12.c.

__attribute__ ((used,section(".FlashConfig"))) const struct {
    unsigned int word1;
    unsigned int word2;
    unsigned int word3;
    unsigned int word4;
} Flash_Config = {0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFE};  //if you dont want to secure the chip

Details please find in 29.34.3 Flash Security Register (FTFE_FSEC)

Regards,

Jing