Thank you for your responses.

I've disabled as well IDATA clearing in the Keil startup.a51 and have reviewed all code between boot and the application, so I'm even more convinced the sucker is doing me a 'favor'.

Chip is taking a reset from time to time when a solenoid is energized with a relay. I was hoping to move some state information outside the area cleared by C startup and use it to come out of reset smelling like a rose. I've reduced the likelyhood by many orders of magnitude by timing the relay energizaion relative to AC zero-cross, but being able to eliminate completely the observability of the problem would be real nice.

Have scoured the Analog Devices data sheets and application note pretty closely, so now I'll try to pin AD down on the subject. We'll see what I can find out.

Cheers -- ewd