no2e1 gateware improvements
The gateware needs some improvements to provide all functions required by upper layer :
- Need some way to detect we have no signal (for instance, no pulse at all)
- Need some way to detect incoming AIS (all ones)
- The RX generated tick should still be generated even if no signal was ever received. ATM it's off until we get a signal and then it continues even if we loose the signal, but it'd be better to have it from the start so that in a 'remote tick' confix, the tx side runs directly. Its phase will obviously be off for when we get a signal but that's not different from the caser where we loose signal and re-acquire ...
Put all in one issue because the hw changes will most likely be interlinked and have to be implemented/designed at once since they interact with the same part of the circuit (RX clock recovery mostly).