Visit the Sri Varahaswami temple before taking the darshan of Sri Venkateswaraswami. As per traditions and legend, Varahaswami owned the seven hills and agreed to give them to Sri Venkateswaraswami with the stipulation that he too is worshiped. you want to more information check it here: http://www.tirupatidarshan.org/about-tirupati-darshan/