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lnis-uofu / OpenFPGA

An Open-source FPGA IP Generator
https://openfpga.readthedocs.io/en/master/
MIT License
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Can OpenFPGA build a bidir segment FPGA architecture? #48

Closed colleen-rin closed 4 years ago

colleen-rin commented 4 years ago

Hi, can OpenFPGA build a bidir segment FPGA architecture? I tried to change a undir segment FPGA, which was k6_N10_sram_chain_HC_template.xml, to a bidir segment by modifying the content of the <segmentlist> tag and the <switchlist> tag. This way was successful in VPR, but was failed in OpenFPGA. I tried to look for the example xml files of the bidir FPGA architectures, but I found no one. I also read the OpenFPGA documentation, but I couldn't find the content about describing a bidir FPGA architecture.

tangxifan commented 4 years ago

Hello, Currently, we support uni-direction architecture mainly. If you try to run a bi-dir architecture, OpenFPGA will tell you clearly it is not yet supported. This decision is based on the well-known paper Directional and single-driver wires in FPGA interconnect The majority of modern FPGAs use uni-directional routing architecture, which is far more efficient than the bi-directional.

However, it is not difficult to support bi-directional routing in the OpenFPGA data structures. If you are interested, we can talk.

Best regards, Xifan Tang

colleen-rin commented 4 years ago

Hi, Thanks for your response. I am still interesting about describing a bidir structure in the OpenFPGA. If you can discuss it with me, I will be very grateful!

tangxifan commented 4 years ago

Hello, Can you provide me an email address? So we can schedule a conference call? Thanks