10-26-2016 02:09 PM
Hi,I have a problem with receiving Interrupts from an external bus to my host computer via a Cyclone IV GX FPGA. Short description of my System: - I have an external Bus-System (About 10MHz) with 8 interrupt lines. - The Interrupt lines are directly connected to the FPGA. (Well, with Schmidt-Triggers) - The Interrupt-Lines are then routed to my QSYS-System which only holds The PCIe HIP and a Interrupt-Bridge with 8 Inputs to route the interrupts to PCIe HIP. - The FPGA is connected with PCIe Gen 1, one Lane to an Intel Atom-Processor - My OS is Linux Debian 7 - I wrote a small Kernel Module which counts the Incoming MSIs so I can read the number with <cat /proc/interrupts>. Now I generate some Interrupts on my external bus just by pulling the lines to ground with a burst generator (self made on a DE0nano). And everything works (nearly) fine. The problem is: about 0,5 to 2 percent of the interrupts get lost on the way. I checked the Interrupt-Signals even on the Interrupt-Port on the PCIe Core with LAI. The Signals don't get lost until they reach the PCIe Core. I send only one Interrupt on the external bus in about 500us. I don't think this is too fast, right? Do you need further information? Or am I doing something terribly wrong? Is there an Issue with the PCIe Core?
11-14-2016 01:31 PM
OK, sorry for that. It was a problematic configuration in BIOS which caused a massive CPU-Load.Afterreconfiguring BIOS the Interrupts are functioning in normal parameters.