I am a FPGA developer working in Verilog with an X310 writing code in a custom RFNoC block. I recently got independent streaming control working to output samples at my discretion to a streaming endpoint then through the cross bar but I do have some questions on parts of the control behavior.
It’s not clear to me what the difference between End of Burst (EOB) and End of Vector (EOV) is or when I need to use one or the other. My current design only uses EOB on the last data packet while EOV is always set to 0. I’m getting underflow errors occasionally but I can’t confidently say which packets they’re associated with. I also need to send a second packet with EOB high to flush the first packet out of the buffer; my guess would be that the first EOB would force a buffer flush. Is there any
I’m also wondering if there is a way to precisely schedule samples or packets for transmit out of the radio. I’ve observed that because the data is processed at ~215 MHz in the RFNoC block and fed into the DAC at 200 MHz pauses have to be included between each packet to prevent overfilling the transmit buffer but this also means that a timing in the 215 MHz domain may not be reflected in the 200 MHz domain. Is there a way to tell the transmit logic/front end to start transmitting at a particular time either in the CHDR header or using the timestamp? Or am I at the mercy of the front end components without any fine control of transmit timing?
