Method and apparatus for context switching of multiple engines

A processor having multiple independent engines can concurrently support a number of independent processes or operation contexts. The processor can independently schedule instructions for execution by the engines. The processor can independently switch the operation context that an engine supports. The processor can maintain the integrity of the operations performed and data processed by each engine during a context switch by controlling the manner in which the engine transitions from one operation context to the next. The processor can wait for the engine to complete processing of pipelined instructions of a first context before switching to another context, or the processor can halt the operation of the engine in the midst of one or more instructions to allow the engine to execute instructions corresponding to another context. The processor can affirmatively verify completion of tasks for a specific operation context.