Memory buffer gets written from unknown source

[JKris.17]

Dear all,

I'm working on a project with a waveshare eink display. I'm using the STM32F103RET6 controller and CubeIDE as development environment. I'm building my application as a c++ application with the FreeRTOS lib. 

My Display class has a 4000 byte buffer containing the current image. I initialize the buffer as all 0's and this works fine. However, during the code that prepares the image with some text, the buffer seems to get written from a different place in the application. When I set a watchpoint on one of the bytes in the buffer that gets written, It triggers on the TIM1 IRQ handler. Tim1 is used as sys clock. (see image for the trace) I don't see any relation between this timer and the buffer. 

Any idea how to debug this situation? Many thanks in advance!

Regards, JOK

[waclawek.jan]

> I don't see any relation between this timer and the buffer.

Show context - source, disasm of code before the point where it stops, processor registers. 

JW

[JKris.17]

Sorry, this question can be closed. I forgot to add a reference symbol in a function that needs my display object as argument. Instead of the reference it created a copy of the display object and this gave strange behavior.Thanks anyway