Hello,
In a Fast Standby example project, I defined an array arr in the .standby_data section, but this array is not used anywhere in the code. However, if I comment out this array definition, the device fails to wake up from Fast Standby; if I keep it, wake‑up works as expected. Moreover, I noticed that the optimization level also affects the behavior: with -O0 optimization, wake‑up fails, but changing to -Os makes it work. Why does defining a variable in the .standby_data section affect the wake‑up functionality? And why does the optimization level have such an impact?
S32K312 RTD400 S32DS
BR,
Jason
Thank you very much for your reply. After changing the address to 0x20408000, the previously failing cases are now working properly.
By the way, regarding my other thread (S32K3 ADC Optimize DMA Streaming), I replied to you using the new account(Jason07) registered with the company email – I forgot to switch accounts when replying.
Hi@Jason22
Whether you comment out the "arr" array in your program affects the value of __BSS_SRAM_START, which will be used as the initial value of the MSP after a fast wake-up.
If this value is too small, it can cause a stack overflow.
In our example project, we recommend setting this value to 0x20408000, which is the end address of the standby RAM.