Synchronize RTI?

[Wings]

I'm trying to synchronize the RTI in one QG8 system to the RTI in another identical QG8 system. The RTI clock is driven by a very stable (but separate) source on EXTAL pin in both systems.

Is there any way to clear the RTI dividers (other than reset) so I can get synced?

[alex_spotw]

Hi:

I think the best way would be to send a signal from the first device to the second, and measure the propagation delay (both in HW and in SW) to detect that signal. This propagation delay would be added to the RTI time in the second device.

Which RTI period are you using?

Regards,

ALex

[Wings]

Thanks for the reply Alex.

I AM sending a signal from device 1 to device 2. It's a radio packet in a FHSS system. The trick is, once the 1st packet is detected it is up to device 2 to establish the receive window (in time) for all subsequent packets. To do this it computes when device 1 started sending the packet and then sets up the RTI to fall into sync with the start of packets. At least, that's what I'll be trying to do, but the only way I can see how to pull this off is to stop the RTI at the next overflow, then resume it at the start of the next receive window. It would be easier if I could just reset the RTI counters, and even easier if I could set the counter to a specific value.

I could explain why I have to use RTI for this and not a standard timer, but take it from me, I can't.

The RTI clock is 135.417KHz, divided by 2048 to give me a 15ms tick.