Bare-metal on KL03:

[chucksmith]

Hello, after trying out some code on a FRDM-KL03Z, we now want to run it on our bare-metal KL03Z32VFG4 based design. Using KDS and a J-Link, I load the code into the board, but I cannot hit the breakpoint at main(), and cannot even hit a breakpoint in the .S startup file. When I pause the execution, the program counter seems to be in the ROM Bootloader (0x1C00070E). The NMI pin is pulled low on our board, but the flash configuration values in startup_MKL03Z4.s are:

/* Flash Configuration */

    .section .FlashConfig, "a"

    .long 0xFFFFFFFF

    .long 0xFFFFFFFF

    .long 0xFFFFFFFF

    .long 0xFFFF3DFE

I believe the 3D disables the NMI function, and says boot from Flash.

So, how to give our application control?

Thanks

[jeremyzhou]

Hi Chuck,

According to your statement, the MCU obviously are stuck in the Bootloader mode, the 0x30 means the setting of Fig 1.

Actually, you should set the 0x3F to FTFA_FOPT register, instead of  the 0x3D.

                                                                              Fig 1

Have a great day,
Ping

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[chucksmith · Accepted solution]

Hi Jeremy - that got me looking in the right area. I actually had to use a value of 0x3B to get it to boot to flash. Its now working. Thanks.