SPNU151V January 1998 – February 2020
Dual-state support is implemented by providing an alternate entry point for a function. This alternate entry point is used by functions requiring a state change. Dual-state support handles the change to the correct state and, if needed, changes the function back to the state of the caller when it returns. Also, indirect calls set up the return address so that once the called function returns, the state can be reliably changed back to that of the caller.