SYSTEM FOR PROVIDING TRANSITIONS BETWEEN OPERATING MODES OF DEVICE

PROBLEM TO BE SOLVED: To reduce scheduling complexity and to avoid potential dispatcher latency in transitions between non-privileged and privileged operating modes in a device. SOLUTION: A system includes a method of providing transitions between a privileged operating mode 310 and a non-privileged operating mode 304. The method includes: executing an application in the non-privileged mode 304, generating an interrupt to request the services of a privileged function (308), and changing to the privileged mode 310 to execute the privileged function; switching to a privileged mode stack (312), holding a non-privileged register to restore a privileged register (318), and calling the privileged function (322); then restoring the non-privileged register and the stack (324), and returning to the non-privileged mode 304. The privileged function is thus executed as a part of the same thread as the execution (302) of the application. COPYRIGHT: (C)2010,JPO&INPIT