Extensions for Timing Guarantees

We present our on-going efforts to guarantee the timing behavior of a program targeted for the precision timed architecture. We extend both the ISA and the hardware to support a set of timing instructions that allow programmers to control the execution time of a sequence of instructions. Programs written using these timing instructions specify deadlines within the program specification itself, and the hardware architecture enforces them through specific hardware policies. For example, timing instructions may be used to ensure that a segment of code has repeatable timing behavior, or that when a timing requirement is violated, an exception handler is invoked to appropriately address the timing violation. In this paper, we present the supported timing instructions, their semantics, and illustrative examples of their usage.