Can ecu reset mess up ignition timing?

i just got my timing(distributor) adjusted a couple days ago and it was running really well and i was working on the car (92 Plymouth sundance) today and unplugged the negative battery cable which reset the ecu and now it idles kind of rough.. i wasn't working on anything in the engine bay i was replacing my stereo and didn't want to get shocked... so could resetting the ecu affect the timing on the car or is the car learning everything again?