CFSR = 0x00010000, UNDEFINSTR = 1
UNDEFINSTR: Undefined instruction Usage Fault:
0 = no undefined instruction
1 = the processor has attempted to execute an undefined instruction. When this bit is set, the PC value
stacked for the exception return points to the undefined instruction. An undefined instruction is an
instruction that the processor cannot decode. Potential reasons:
a) Use of instructions not supported in the Cortex-M device.

Bad or corrupted memory contents.
HFSR =0x40000000, FORSED = 1
The HFSR has bit 30 set indicating that the Usage Fault
was escalated to a Hard Fault (displayed as the FORCED
bit). This is consistent with the debugger source window
that shows the PC at the Hard Fault handler address.