Visible to Intel only — GUID: iga1463770199797
Ixiasoft
Visible to Intel only — GUID: iga1463770199797
Ixiasoft
38.2.4. Latency Information
The latency of an interrupt request traveling through the VIC is the sum of the delay through each of the blocks. Clock delays in the interrupt request block and the vector generation block are constants. The clock delay in the priority processing block varies depending on the total number of interrupt ports.
Number of Interrupt Ports | Interrupt Request Block Delay | Priority Processing Block Delay | Vector Generation Block Delay | Total Interrupt Latency |
---|---|---|---|---|
1 | 1 cycle | 0 cycles | 1 cycle | 2 cycles |
2 – 4 | 1 cycle | 1 cycle | 1 cycle | 3 cycles |
5 – 16 | 1 cycle | 2 cycles | 1 cycle | 4 cycles |
17 – 32 | 1 cycle | 3 cycles | 1 cycle | 5 cycles |
When daisy-chaining multiple VICs, interrupt latency increases as you move through the daisy chain away from the processor. For best performance, assign interrupts with the lowest latency requirements to the VIC connected directly to the processor.