Patent ID: 7340574

Claim:
An industrial controller, comprising: a memory operable to store a user program and a data table; a memory management unit operable control access to the memory and to store protection data associated with the memory, the memory management unit being operable to signal an abort condition responsive to a memory access instruction conflicting with the protection data; a processor operable to: communicate with the memory through the memory management unit; execute the user program to designate in the protection data a first portion of the memory including the data table as being read-only issue write instructions in accordance with the user program having target addresses targeting the first portion; execute an abort handler invoked by the signaling of an abort condition by the memory management resulting from a selected one of the write instructions having a target address conflicting with the read-only designation of the first portion, the abort handler being operable to flag a second portion of the memory including at least the target address as being modified and allow execution of the selected write instruction.