Could someone tell me what a typical rise time would be for a 2 MHz SPI clock signal driven by an Arduino Micro (ATmega32U4), off the SCK pin? An actual measurement would be preferable, but I do not have the means to do that myself.
Am I right in assuming this would give me a lower limit for the rise times in a circuit driven by the Arduino SCK signal?
I could not find any useful information about the actual rise time on the web: not in the Arduino docs, nor on the Arduino forums, nor here on EE. The ATmega32U4 spec sheet only specifies an upper limit for SPI rise time at 1600 ns, as far as I can see.
Based on the clock frequency of 2 MHz I could assume a rise time of 1% of the clock period, i.e. 5 ns, but that would not be much better than a random guess.