Information about ARM System control registers.

Hi all,

I noticed there are multiple system control registers in ARM.

The SCTLR_EL1 , SCTLR_EL2 and SCTLR_EL3.

I want to know, what do multiple such system controls registers represent??

I am particularly interested in the A bit of the system control register.

How does the A bit work when all these registers are involved?

For instance, When the A bit is enabled in say SCTLR_EL1 but not in SCTLR_EL2, what happen in case of an unaligned access? 

Do we encounter a segmentation fault?

if yes why?