[email protected] said: > I'm looking for a possibility to make an automatic switching between the > internal µC oscillator (Atmel µC) to the 10MHz output of my thunderbolt to > use it as a precise µC clock. Has anybody an idea how to do best without > disturbing the accuracy of the ref. signal?
It's a bit tricky, but doesn't take much logic after you get it. Xilinx has that feature in at least one of their FPGAs. The circuit may be in a data sheet or app-note. I'm pretty sure the details were discussed on the usenet FPGA group. That was several/many years ago. The problem is that you have to avoid runt clock pulses and metastability. It also has to switch to a clock when the other clock has stopped. Another approach might be to PLL the local clock to an external reference. -- These are my opinions. I hate spam. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
