S32 Design StudioのトピックRe: sk14x Filling unused memory

sk14x Filling unused memory

wujiabin — Mon, 11 May 2020 07:29:51 GMT

Hi all. I am using s32ds for projects development. For safety reasons, the unused/remaining ROM must be filled. From other threats I've learned that the remaininngs will be flashed with 0xFF by default. Questions are: 1, will all the unused cells be filled? 2, whats the conquence of 0xFF, I mean, what wouldhappen if the pointer accidently jump to it?

much thanks in advance!

Jiabin.

Re: sk14x Filling unused memory

jiri_kral — Mon, 11 May 2020 08:36:54 GMT

Hi,

empty ROM has 0xFF value. Prior programming is performed mass erase - all Flash is set to 0xFF.

If program jumps into unused memory - program ends in exception because of unknown instruction.

You may find helpful this thread - https://community.nxp.com/message/1234820?commentID=1234820#comment-1234820

Jiri

Re: sk14x Filling unused memory

ErichStyger — Mon, 11 May 2020 08:59:16 GMT

By default erased flash cells have the value of 0xff.

For safety reasons I do fill memory with a predefined pattern to catch error cases easier.

See FILLing unused Memory with the GNU Linker | MCU on Eclipse how to do this with the linker.

I hope this helps,

Erich

Re: sk14x Filling unused memory

wujiabin — Tue, 12 May 2020 09:16:36 GMT

Thanks Jiri, it helps.

Re: sk14x Filling unused memory

wujiabin — Tue, 12 May 2020 09:22:46 GMT

Hi Jiri,

by "ends in exception" you mean, no software restart or something, just stop there and wait for power-on-reset?

Re: sk14x Filling unused memory

jiri_kral — Tue, 12 May 2020 11:04:02 GMT

Hi,

program ends in exception handler - which is by default infinite loop with no instructions. You need to reset board (or wait for watchdog - if it is enabled)

Jiri

Re: sk14x Filling unused memory

wujiabin — Wed, 13 May 2020 01:20:51 GMT

thanks jiri, very helpful!