Jitter free

 

 

The fido family provides users with a predictable performance that meets the tight time constraints of real-time and safety-critical systems. The Deterministic Cache permanently stores critical pieces of code that need to be executed fast. When the code needs to be executed, it is there each and every time - eliminating cache misses and producing a consistent response time.

Since fido is addressing control applications that require deterministic response, we want to eliminate jitter. One major cause of jitter is the cache on modern processor cores. Cache is used to help overcome the performance bottleneck of processors that have to fetch instructions from memory. (RISC processors really need a Cache since more instructions have to be executed to carry out a task). The problem is that the contents of the cache depends on what was previously executed. When an interrupt occurs, the cache may or may not have the correct code pre-loaded. Thus a conventional cache is not deterministic. It is this very reason that designers of real-time control systems often prefer not to use cache or disable the cache in the microcontroller.

With fido, once again we have taken a different approach. We still wanted a cache to speed up the execution of frequently used code blocks. However by allowing the customer to decide which code resides permanently in the cache, jitter is eliminated. We also provide profiling tools to easily allow the customer to identify frequently executed code blocks.