Nios® II Embedded Design Suite (EDS)
Support for Embedded Development Tools, Processors (SoCs and Nios® II processor), Embedded Development Suites (EDSs), Boot and Configuration, Operating Systems, C and C++
Intel Support hours are Monday-Fridays, 8am-5pm PST, except Holidays. Thanks to our community members who provide support during our down time or before we get to your questions. We appreciate you!

Need Forum Guidance? Click here
Search our FPGA Knowledge Articles here.

Nios II SPI Slave


Hello everyone,

I am working on a project that utilizes SPI (3 Wire Serial) IP as the slave for my Nios. I will get 8 frames of 16-bit data, which will be read by Nios. But somehow the IRQ is only triggered once and I only received the last frame. I followed the Example Test Code provided in the "Embedded Peripherals IP User Guide" and enabled the IRQ in the IP core register for the IRRDY using:


But the IRQ still comes once at the end. I checked the SignalTap and discovered that the IRQ is only triggered at the end after the SS_n signal is toggled back to 1, so I will always get the last frame of the data when reading the rxdata. The picture shows the SignalTap when the script is running. Is there any way to trigger the IRQ after every frame of the data?

Thank you

0 Kudos
1 Reply

May be you check if you turn on the synchronizer for your slave.