topic Re: lpc54628 keil optimization problem in LPC Microcontrollers

lpc54628 keil optimization problem

omeraygor — Tue, 29 Jun 2021 11:09:23 GMT

Hi,

i have lpc54628 development board. i am developing code over it. So my problem is about optimization.

Using keil software to write code. But there are very big problem. Without optimization, the codes doesnt work. But when i opened optmization, on the debugger jumps another location that is not in my code sequence.

i attached my settings.

i am working firsty arm compiler 6. i dont know what can i do about this? any help please.

Re: lpc54628 keil optimization problem

converse — Tue, 29 Jun 2021 12:34:47 GMT

Most likely a problem in your code. See this FAQ and read the section on Optimised code fails to execute correctly (although written for gcc, the same advice applies).

https://community.nxp.com/t5/LPCXpresso-IDE-FAQs/Compiler-Optimization/m-p/468819

Re: lpc54628 keil optimization problem

frank_m — Wed, 30 Jun 2021 05:48:35 GMT

> But when i opened optmization, on the debugger jumps another location that is not in my code sequence.

This is a common effect with optimized code. There is no one-to-one relation between C source lines and assembler instructions anymore, and lines or variables are removed (optimized out). Don't get confused with single-stepping your code.

First check if the code behaves correctly, i.e. according to your intended functionality.

If not, you might need to rework your code, as Converse suggested.

Re: lpc54628 keil optimization problem

omeraygor — Tue, 03 Aug 2021 09:36:42 GMT

hi,

thanks your advice. i am checking code again. same of code is working good and debugging correctly. can be about header files?

Re: lpc54628 keil optimization problem

converse — Tue, 03 Aug 2021 15:20:27 GMT

No, it is not header files. Most common reasons (but not the only possibilities) are

- not using the volatile keyword on a variable that is modified on mainline code and interrupt handler

- using a delay loop (e.g. for(int i=0; i<1000; i++) that gets optimised away