1. In a computing device providing a graphical modeling environment, a method for executing a function on a selected processor in an environment external to the graphical modeling environment from the graphical modeling environment, the method comprising: altering data held by one or more memory locations accessible by the selected processor, resetting a program counter on the selected processor to a start location of the function, executing the function on the selected processor from the graphical modeling environment, the selected processor being external to the graphical modeling environment, halting the program counter on the selected processor, reading data held by the one or more memory locations accessible by the selected processor, and managing context switching between the graphical modeling environment and the selected processor.