Important: The information in this document is obsolete and should not be used for new development.
Setting and Restoring the A5 Register
Any code that runs asynchronously or as a callback routine and that accesses the calling application's A5 world must ensure that the A5 register correctly points to the boundary between the application parameters and the application global variables. To accomplish this, you can call theSetCurrentA5
function at the beginning of any asynchronous or callback code that isn't executed at interrupt time. If the code is executed at interrupt time, you must use theSetA5
function to set the value of the A5 register. (You determine this value at noninterrupt time by callingSetCurrentA5
.) Then you must restore the A5 register to its previous value before the interrupt code returns.
Subtopics
- SetCurrentA5
- SetA5