I'm trying to learn Verilog and FPGA and just bought my first FPGA. It's a Lattice iCEstick.
It comes with a 12Mhz clock but I wonder If I can sample synchronous inputs with a clock faster than that. I don't know much about FPGAs but I think that the onboard clock is just a tool you can use but some parts of the design can use another external clock or no clock at all. I'm thinking about counting pixels in a HDMI connection, for example. It might use a higher frequency.
I guess heat and logic gate change and stabilization time might limit the clocks frequencies.
Am I right about these things? How can I know the limits?