Patent ID: 7516311
Filing Date: 2009-04-07
Classification: G06F

Abstract:
1. A method of operating a microcontroller comprising: providing a deterministic microprocessor unit; providing a real time operating system for said deterministic microprocessor unit; providing a hardware context manager comprising hardware circuitry operable to selectively determine one of a plurality of contexts of operation of said microcontroller; providing a plurality of sets of hardware context registers, each set of hardware context registers being usable to store context information for a predetermined corresponding one context of said plurality of contexts; assigning said real time operating system to a first context of said plurality of contexts; assigning a plurality of other functions to the remaining ones of said plurality of contexts operating said hardware context manager operating to select an active first context; operating said hardware context manager to select for said active first context a corresponding first set of hardware context registers from said plurality of sets of hardware context registers corresponding to the selected active first context of said plurality of context; operating said hardware context manager to select a active second context in response to an interrupt; operating said hardware context manager and said plurality of sets of hardware context registers in response to said interrupt to switch from said first set of hardware context registers to a second set of hardware context registers corresponding to said second context and interrupting execution of said active first context without changing the contents of said first set of hardware context registers; subsequently operating said hardware context manager to reselect said first context to be active, said hardware context manager switching to said first set of hardware context registers, said first context continues executing directly from the contents of said first set of hardware context registers such that switching to said first context occurs in one clock cycle.