I'm doing some GPS work myself right now, although not with an 8052. In my case I'm just receiving NMEA sentences from a GPS receiver and I personally wouldn't trust it to more than about +/- 0.50 seconds accuracy because of the fact that the information is delivered in a serial fashion at 4800 baud. So even if the GPS has the right time it is doubtful that you're going to get very precise time after the delay introduced by the 4800 baud transfer is factored in.

This GPS clock promises accuracy to within 75 nanoseconds. But that's the marketing material and probably depends on "best case" conditions.

I'm skeptical you could get 50 nanosecond accuracy, although I may be mistaken.

Why do they need so much accuracy? :)

Regards,
Craig Steiner