why would a hard-fault be generated during a flash sector erase on the KL28?

trevorhunt — Fri, 27 Jul 2018 09:48:47 GMT

I wonder if you might be able to help me with a problem I am having here using the KL28..

Basically, I am using a function to erase a sector of flash on the KL28, the function is running from RAM (and code is generated using GCC compiler)..

If I run the function as shown below without a “nop” instruction at the end of the function I get a ‘hard-fault’ generated.. I can’t figure out why the ‘nop’ instruction would have any effect..

I have compared the disassembly with and without the ‘nop’ and its pretty much the same…

Here's the function..

here's is the disassembly comparison of the code generated when i insert the 'NOP' versus the when the 'NOP' is removed, they are practically the same except for whats shown in the snippet below..

I wonder is there a delay required after issuing the flash cache instruction before returning from the function..

Any help would be much appreciated.. I am pulling our hair out here.. :-)

regards

Trevor

Re: why would a hard-fault be generated during a flash sector erase on the KL28?

FelipeGarcia — Tue, 31 Jul 2018 20:40:17 GMT

Hi Trevor,

I replicated the issue on my side by copying your function in the pflash example that it's in the KL28 SDK (using MCUXpresso) and I was able to run the project with or without the nop so I have the following comments:

-Are you able to know the address of the highlighted instruction in the following snippet? I believe is not an issue caused by the nop I think your function is not returning correctly.

-As you can see in the following snippet when I run the project I get the next instructions in disassembly and there are some differences, the highlighted instructions is the one that exits the function.

I hope this is useful.

Best regards,

Felipe

Kinetis MicrocontrollersのトピックRe: why would a hard-fault be generated during a flash sector erase on the KL28?

why would a hard-fault be generated during a flash sector erase on the KL28?

Re: why would a hard-fault be generated during a flash sector erase on the KL28?