Great discussion. I am working on SPI.. I want to make STM32 controller works at 72 Mhz as SPI Master and Basys 3 as SPI Slave that has frequecy of 100 Mhz. I have read somewhere that SPI Master frequecy <= 2 (SPISlave frequecy). So, I have to add any clock divider in BASYS 3 VHDL code or it will work fine without that as it fulfills the condition.