I have been able to get the Event Recorder mostly working with ARM-MDK 5.27, in order to get debugging messages out of my STM32F0 (Cortex-M0) MCU. However, I've run into two issues that I am hoping someone here can help me resolve. I have not been able to find definitive answers to either in numerous web searches:
1. On my MCU, configuring the Event Recorder record count appears to use more RAM than expected. I have set my record count to 64U, which should account for 1,024 bytes (16 bytes per record). However, when I allocate an uninitialized IRAM2 region of 1,024 (0x400) bytes, I get an error than the allocation is not enough:
myproject\myproject.axf: Error: L6220E: Execution region RW_IRAM2 size (1252 bytes) exceeds limit (1024 bytes). Region contains 0 bytes of padding and 0 bytes of veneers (total 0 bytes of linker generated content).
Where do the extra 228 bytes come from? I can only allocate record counts in 2^n numbers, and whatever number I pick (64U, 128U, etc.) results in an overrun of IRAM2 when compiling, even when increasing the allocation of uninitialized IRAM2. I have to use a larger uninitialized IRAM region (e.g., 2,048 bytes) and a smaller record count (e.g., 64) in order to compile without errors. This is a waste of at least 796 bytes of RAM for a 2,048 byte allocation. How can I work around this?
2. On the same MCU, attempting to set the Event Recorder to use its time stamp source as SysTick results in a linker error about multiple definitions of SysTick_Handler:
myproject\myproject.axf: Error: L6200E: Symbol SysTick_Handler multiply defined (by eventrecorder.o and stm32f0xx_it.o).
If I define the time stamp source to be the DWT Cycle Counter, I get a warning. From my reading, it seems like DWT is emulated in the Cortex-M0, but I still get the warning:
C:\Keil_v5\ARM\PACK\Keil\ARM_Compiler\1.6.1\Source\EventRecorder.c(660): warning: #1215-D: #warning directive: "Invalid Time Stamp Source selected in EventRecorderConf.h!"
I want to confirm that this is working correctly with DWT and not going to cause issues.
Thanks in advance for any help!