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vhdlhdlvlsiaxi4

AXI4 delay transactions

I am just looking for advice. I currently have a custom IP integrated in VHDL which has a AXI4 slave input and an AXI4 master output, and currently the signals are directly tied together.

I would like to add a customizable latency to the AXI signals, so that way they can be delayed for a particular amount of time through the IP, rather than being connected to each other.

My question is; can I delay read and write transactions through the IP merely through the use of the AxVALID and AxREADY (and maybe the RVALID/RREADY and WVALID/WREADY) signals?

If for instance I wanted a 20 clock cycle delay, I could wait for an external master to assert VALID, and wait 20 clocks before having the IP slave assert READY? Is this correct logic?

Thanks in advance for any any advice.

Solution

  • Yes, that can be done. Depending on your infrastructure it can cause bus congestion. Alternatively, you should also insert a FIFO to buffer these delayed bus transactions.