I want to try some frequency higher than 100Mhz on DE2-70.I built a simple system( only mcu, sysid, onchip-ram and jtag-uart) . But I cannot get it work with 105 ,116.6 or 120 Mhz, I even can not read the sysid. Is 100Mhz the fastest speed I can get?
I'm not aware of an upper limit for the debug module but there is a minimum frequency requirement of 20MHz.Is your design meeting timing? I would expect that even without timing constraints it should have still worked assuming timing was met.
My design is based on DE2_70_SD_Card_Audio_Player (from Teriasic's DE2-70 CD). The jtag-uart is running at 50Mhz behined the pipeline_bridge. But I didn't take a look at other timing constraints.