[time-nuts] Seeking feedback on a HW Architecture for a DIY two channel timer/counter and frequency reference

[Erik Kaashoek]

Some time ago I have shared some info on the timer/counter project I'm 
working on.
Based on the excellent feedback from this community I've made some 
changes to the HW architecture.
The goal is a simple and cheap HW, possibly leading to a product that 
can be sold for around $100.
An architecture level overview can be found here: 
http://athome.kaashoek.com/time-nuts/Architecture_2.JPG
Not shown is a touch LCD display that runs the user interface.
The device will have two inputs (channels A and B) with AC or DC 
coupling, user definable trigger levels and up or down trigger edge.
One input will have an optional pre-scaler
A third input can be used either for a GPS antenna for the internal 
10MHz GPSDO or for input of an external 10MHz reference.
A separate output can provide either the internal 10MHz reference or a 
frequency derived by integer divide from this internal reference, such 
as 1MHz or 1Hz. The phase of the output is locked by the GPSDO to the 
GPS PPS
Given the form factor, 4 inputs/output is the maximum possible.
Does this setup of inputs/output make sense?
Are there any suggestions for improving this architecture?
Erik.