[time-nuts] Re: Network interface cards that support timestamping

[Lux, Jim]

On 1/30/23 12:28 PM, S McGrath via time-nuts wrote:
> Most common way of getting 1PPS into a computer without a dedicated 1PPS
> interface is to drive a RS-232 port’s Carrier Detect pin (pin 1 on DB-9)
> with the 1PPS signal



back in the day when that tied directly to an interrupt with consistent 
latency, that works pretty well.


These days, though, there's often USB hosts in the way, or some other 
intermediate interfaces that increases the uncertainty in timing of 
"when software does something" in response to "external event"