Device and method for performing high-speed low overhead context switch

A processor having a high speed low overhead context switch capability, the processor is adapted to handle tasks of various priority, the processor comprising:

• a central processing unit;
• register files, coupled to the central processing unit;
• a memory module, coupled to the register files, adapted to store task contexts;
• a control unit, coupled to the central processing unit, to the register files and to the memory module;
• wherein the control unit is adapted to receive a forward request for handling a task that has higher priority than a current task that is handled by the processor, to switch between a current register file that stores the current task context to another register file in a manner that the central processing unit is able to access the other register file, and to transfer a current task context from the current register file to the memory module;
• and
• wherein the control unit is adapted to receive a backward request for resuming the handling of a previous task, the handling of the previous task previously being halted as a result of a request to handle a higher priority task, to switch between a register file that stored a higher priority task context, to a previous register file that stores a previous task context in a manner that the central processing unit is able to access the previous register file, and if the memory module stores a context of a task that has lower priority than the previous task to transfer a lower priority task context to another register file.

A method for performing high speed low overhead context switch in a processor, the method comprising the steps of:

• handling a current task;
• wherein a CPU of the processor is allowed to access a current register file;
• receiving a request for handling a higher priority task, and accordingly switching between the current register file to a higher priority register file and transferring a current task context from the current register file to a memory module;
• jumping to the step of handling a current task wherein the higher priority task becomes the current task and the higher priority register file becomes the current register file;
• and
• receiving a request for resuming to handle a lower priority task, and accordingly switching between the current register file to a lower priority register file;
• if an even lower priority task context is stored in the memory module the even lower priority task context is transferred to the current register file;
• jumping to the step of handling a current task wherein the lower priority task becomes the current task and if there is an even lower priority task it becomes the lower priority task.