How to build on the iOS device with armv7s architecture ?

Hi everyone, I would like to ask if there anyone could build unity project on the iOS device with ARMv7s architecture ? I go to **Build Settings > Player Setting> Other Settings > Configuration > Architecture** There are only three options to choose: **ARMv7, ARM64, Universal** I tried to build the application on iPad 4 (ARMv7s) but it seems some problems happened, like rendering is not stable. But if I build on other iOS devices with ARM64 or ARMv7s, they all work well! anyone know how to solve it? btw, My current Unity version is 5.2.0f3, and my Xcode is 7.2 Thanks!!!