Strange stack behaviour question.

Hi,

It's about the STM32F103. Due to my previous post my application first fills all (at that moment) free stack memory locations with a value of 0x55555555. This all works fine so does the application. I can monitor the stack behaviour in the Memory1 debug window.

But what I see is that at a certain moment data is placed in the stack at some location leaving some gaps of 2 to 10 times (32-bits) dwords containing 0x55555555.

The stack grows downwards in memory addresses.
For example I see: (highest memory on top)

Address Data
0xnnnnnnnn-0 data start of stack
0xnnnnnnnn-1 data
0xnnnnnnnn-2 data
0xnnnnnnnn-3 0x55555555
0xnnnnnnnn-4 0x55555555
0xnnnnnnnn-5 data
0xnnnnnnnn-6 data
0xnnnnnnnn-7 0x55555555
0xnnnnnnnn-8 data
0xnnnnnnnn-9 data
0xnnnnnnnn-10 0x55555555
0xnnnnnnnn-12 0x55555555
until
0xnnnnnnnn-nn 0x55555555 end of stack

I do use many interrupt handlers.
Is there an explanation for this or is my application buggy?

Thanks

Henk