High RAM Application Questions

[Dave_couling]

According to the *.map file the .bss (RAM) usage for my Application is 0x16b8 or 5816 bytes. This is obviously a very high RAM Application, likely due to the abundance of app_timers I use. I am using SDK6.1 and SD7.1. I want to make sure I'm not going to run into RAM issues at RUN-TIME. With this RAM spec in the .map file do I need to modify the gcc_startup_nrf51.s ? Or modify any other files to account for this RAM usage? Any other considerations I should be mindful of? Thank you for your advisement Nordic.

-DC

[RK]

Don't totally understand the question. If the app links without error and fits in the available space, it works, the link script has a check for this. The startup file is entirely generic and just copies things from one place to another, it doesn't matter if it copies 1 byte, 10 bytes or 16Kb.

What issues were you concerned about, perhaps I'm just missing the point?

That is a lot of RAM usage, the map file should tell you what it's all used for, although they're annoyingly tricky to read, you might want to confirm to yourself that it is app timer usage (they use that much??) and not something else.

[RK]

One of those hard debugging situations, it only breaks when you're not looking. What errors cause the LED to turn on and the next push to reset? APP_ERROR_CHECK(), hardfault, all of the above? That might help fractionally to narrow it down, but you probably have lots of app error checks so it may not.

You can run release firmware on a board and still get a debugger on it when it fails. That at least gives you a stack trace and there's enough information in the original binary file to figure out where you were, especially if you've built release code (ie optimized) with debug info.

You need some kind of post-mortem when the thing fails, somehow, it's the only way.