Directory Interface - How Psoft HCM -> Active Diretory integration is triggered?

I am trying to find out PeopleCode or Setup that triggers the integration. I read in PeopleBooks, Directory Interface keeps employee data in sync. I am trying to understand what triggers it. For example, at the time of Hire, I want to send employee information (including emp name) but if employee changes name, I don't want to publish it to AD as it requires certain manual steps. So how can I disable name sync when only name is changed? Is there a PeopleCode that I will have to disable or it's driven by some setup.

Thanks,