Data is processed in an embedded system by writing data read from a peripheral device in response to an event to memory external to the embedded system. The data or a portion of the data is copied to memory internal to the embedded system. Which portion of the data is stored in both the external memory and the internal memory is tracked. The copied data is retrieved from the internal memory by a processor included in the embedded system. The processor has one or more caches logically and physically separated from the internal memory. The processor uses the copied data it retrieved to begin servicing the event.