Visible to Intel only — GUID: lro1402071734825
Ixiasoft
Visible to Intel only — GUID: lro1402071734825
Ixiasoft
36.1. Core Overview
A processor running a program can be instructed to divert from its original execution path by an interrupt signal generated either by peripheral hardware or the firmware that is currently being executed. The processor now executes the portions of the program code that handles the interrupt requests known as Interrupt Service Routines (ISR) by moving to the instruction pointer to the ISR, and then continues operation. Upon completion of the routine, the processor returns to the previous location.
Intel FPGA's Interrupt Latency Calculator (ILC) is developed in mind to measure the time taken in terms of clock cycles to complete the interrupt service routine. Data obtained from the ILC is utilized by other latency sensitive IPs in order for it to maintain its proper operation. The data from the ILC can also be used to help the general firmware debugging exercise.
The ILC sits as a parallel to any interrupt receiver that will consume and perform an interrupt service routine. The following figure shows the orientation of a ILC in a system design.