How to Unlock a MAX78000 That Can No Longer Be Programmed

[PYL4869]

Hi
for a custom board design, I had some problems with my DAPLINK drive, you can refer to thishttps://github.com/ARMmbed/DAPLink/issues/1070, It can download normally, but erase.act cannot be used, about this questionhttps://github.com/MaximIntegratedAI/MaximAI_Documentation/blob/main/MAX78000_Feather/README.md#how-to-unlock-a-max78000-that-can-no-longer-be-programmed, I may not be able to use "erase.act"allowing the device to be programmed again, Is there any way to unlock the non-programmable MAX78000?

Besides that, how is your "UART 0" related to "printf"? This is the only one I found in the startup folder, and it doesn't seem to associate "UART 0" with "printf".

[EricB-ADI]

@Jake-Carter May be able to help you more with your first question.

Regarding UART0 and printf. The board.h file refers to UART0 as CONSOLE_UART.
Then Inside the MiscDrivers folder is the stdio.c file, which implements
the stubs required for printf. You can see it defining the UART from ```CONSOLE_UART`` at

msdk/Libraries/MiscDrivers/stdio.c

Line 79 in b71451d

#define MXC_UARTn MXC_UART_GET_UART(CONSOLE_UART)

Then the putc implementation which printf requires uses our normal UART drivers

msdk/Libraries/MiscDrivers/stdio.c

Line 188 in b71451d

MXC_UART_WriteCharacter(MXC_UARTn, c);

[Jake-Carter]

@PYL4869 see #883

You may be encountering a bug I found with DAPLINK firmware SHA "a209", which caused it not to drive the RSTN pin correctly.

[PYL4869]

@Jake-Carter
Hi, I may not have made this clear.
for a custom board design, I had some problems with my DAPLINK drive, I made my DAPLink device using "STM32103CBT6", After my tests, I found that I could not erase MAX78000 using "eraser.act" in "MSD command", you can see this, I may not be able to use "erase.act"allowing the device to be programmed again, Is there any other way to unlock the unprogrammable MAX78000?

For this, Either in the MAX78000FTHR or my custom board design, when the download cannot be performedthis VS Code "erase flash" build task does not work.

For this, because I use STM32103CBT6 to make my DAPLink device, it should not solve my problem.

For my custom board design, how to Unlock a MAX78000 That Can No Longer Be Programmed ?

[Jake-Carter]

@PYL4869 since you are using an STM device as your DAPLINK device I can't provide much support on the implementation. I would suggest reaching out to ST support instead.

Can you at least connect to the MAX78000 at all? Try the following command. It will print some extra debug info as well (-d3)

openocd -s $MAXIM_PATH/Tools/OpenOCD/scripts -f interface/cmsis-dap.cfg -f target/max78000.cfg -c "init;" -d3

(Note the MAXIM_PATH environment variable should be set, or replace it with the full path to the MSDK install)

If it also fails, then you may have some fundamental issues with the DAPLINK firmware/build. The errors above look like the debugger cannot even find the MAX78000 at all. So you will need to resolve that before you can proceed to erasing the device