I wanted to implement a GPS disciplined TCXO. I'm choosi g a P2 because of the interrupts. The GPS module I have outputs a 1bps signal, but no 10MHz signal. So, I'm planning to use a P2 to count the frequency from the VCTCXO, using the positive edge from the 1bps coming from the GPS module.
The P2 will also monitor the lock signal from the same module, pass SPI communication to that module, and output to a low noise DAC that controls the Vref of the VCTCXO to fine tune it.
In essence, I need to use a counter to count the 10MHz ish frequency from the VCTCXO, triggered by the rising edge of the same signal. The counter needs to be started and then stopped by the rising edge of the 1bps signal from the GPS module. I would prefer to implement an interrupt for that start/stop function, to ensure accuracy and no latency.
Is it feasable? I would choose the P1, but I think I need an interrupt.
Kind regards, Samuel Lourenço