Nios II core minimal frequency?

Hi Jan,

That is a good question... I do not have data readily available to answer you but one thing immediately comes to mind: JTAG. If you're using the JTAG UART or debug core, these have a second clock, JTAG Tck, coming in at a frequency that depends on your board/programming cable (max 10MHz or so, I think). I am not familiar with the inner-workings of logic between the JTAG and Avalon/Nios clock domanis, so I cannot speculate further, but you might try 10MHz in the interim to see if this gives you a working system.