Thank you, Arthur! I actually discovered this just before I read your email. When I realized I wasn't actually specifying the slave device, I punched it into the SPI_SSR during a breakpoint and that didn't work. When I saw someone's example that called XSpi_SetSlaveSelect, the clock (and select line) started to work. What threw me was that in the example, they run in loopback mode and they don't need to bother with setting the slave select. It was hard to find an example that used external pins (and not loopback). Next, I have to add a second SPI device, so I guess I need to add a constraint to specify which pin the new SS will come out on. Can I use a GPIO, or will there be a conflict?- I am never quite sure how Vivado reads the board file pin locations.
Thanks again, Arthur.
Dave