SAM3S8B Atmel Corporation, SAM3S8B Datasheet - Page 190

• Manufacturer Part Number: SAM3S8B
• Manufacturer: Atmel Corporation

10.20.15 System control block design hints and tips
190
190
SAM3S8/SD8
SAM3S8/SD8
Ensure software uses aligned accesses of the correct size to access the system control block
registers:
The processor does not support unaligned accesses to system control block registers.
In a fault handler. to determine the true faulting address:
Software must follow this sequence because another higher priority exception might change the
MMFAR or BFAR value. For example, if a higher priority handler preempts the current fault han-
dler, the other fault might change the MMFAR or BFAR value.
• except for the CFSR and SHPR1-SHPR3, it must use aligned word accesses
• for the CFSR and SHPR1-SHPR3 it can use byte or aligned halfword or word accesses.
• Read and save the MMFAR or BFAR value.
• Read the MMARVALID bit in the MMFSR, or the BFARVALID bit in the BFSR. The MMFAR or
BFAR address is valid only if this bit is 1.
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12