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why would you want to use Qsys if there isn't a processor involved? I don't see what it buys you.
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Qsys let's you connect a variety of IP blocks relatively easily and it will generate the necessary instantiation and interconnects. Whether or not it is a net positive or negative probably depends on the scope of your system, and likely doesn't have anything to do with whether or not you have a processor in it or not.
TI DSP -> (PCIe or SRIO or addr/data bus or SPI or I2C or ...) -> [Qsys] -> various peripherals
That's a relatively straight forward system to produce.
Personally I think if you're talking about more than a couple peripherals, or are involving any memory controllers / DMA, Qsys makes sense.