In a real-time application, one or more computational tasks execute according to a time schedule and use input data from input devices and/or output data from output devices. One or more of the input devices or output devices may be unscheduled devices that attempt to access the peripheral bus at unscheduled times. Such unscheduled bus access can cause the time schedule to become comprised. Various methods for arbitrating access to the bus to better integrate the bus access with the time schedule followed by the application are described.