On Sat, Sep 12, 2009 at 6:34 AM, Tony Vandiver wrote: > Does the volatile keyword for a variable (using C30 PIC24) guarantee an > atomic operation when accessed regarding interrupts? Volatile doesn't guarantee any atomicity. Generally it is used to define a hardware register where the register contents can change: This tells the compiler not to optimize such areas, where it can cause weird effects. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist