Editing Bus error (section)

===Non-existent address===
Software instructs the CPU to read or write a specific physical [[memory address]]. Accordingly, the CPU sets this physical address on its [[address bus]] and requests all other hardware connected to the CPU to respond with the results, if they answer for this specific address. If no other hardware responds, the CPU raises an [[exception handling|exception]], stating that the requested physical address is unrecognized by the whole computer system. Note that this only covers ''physical'' memory addresses. Trying to access an undefined [[virtual memory]] address is generally considered to be a segmentation fault rather than a bus error, though if the [[Memory management unit|MMU]] is separate, the processor cannot tell the difference.