Breakpoint traps are taken precisely. Implementations that emulate misaligned accesses in the software will generate a breakpoint trap when either half of the emulated access falls within the address range. Implementations that support misaligned accesses in hardware must trap if any byte of access falls within the matching range.
Debug mode breakpoint traps jump to the debug trap vector without altering Machine mode registers.
Machine mode breakpoint traps jump to the exception vector with “Breakpoint” set in the mcause register, and with badaddr holding the instruction or data address that caused the trap.