ANSI/CEA 2040
This document describes interfaces between a Common Interface Module (CI Module) located on a microSD card and a Terminal device. The purpose of this standard is to specify the hardware, signaling, and application interface between a digital consumer electronics device e.g. television receiver (handheld, stationary or otherwise) and a small removable, replaceable CI Module that implements and embodies significant portions of a Conditional Access System (CAS).