Crash dump and syslog

Hello
My program crasht and i get core dump file and syslog file.

SIGNAL: 11, ADDR (nil), AT 0xb6c2b908 SI_CODE 0x00000001
ILLEGAL ADDRESS (nil)
LEGATO VERSION
20.04.0_2ea965e52e94cd5936a25400966763a5_modified

what is ?
what does it mean?
AT 0xb6c2b908

Please attach your code that can reproduce the issue.

why do you need my code? if I am interested in the abbreviation AT?
my code is about 3000 lines. what exactly do you want to see there?
How can you match syslog and code?

Can you simplify the code?
I want to see if i can reproduce

not you can not pose this problem.
this is related to the implementation of the modem.
I see that a log of information is stored in the log
registers, stack, id thread. But how to apply this information? Basically, it does not come of any benefit.

Did you try gdb with the core dump