You use the test wrapper for control and observation of the ports during testing of the ETM10RV core and the logic external to the core.

The wrapper scan chain comprises both shared and dedicated test wrapper cells. There is a wrapper cell connected to every functional input and output port that is not connected to the ARM1026EJ-S processor, with the exception of the clock ports.

The test wrapper isolates all ports on the ETM10RV, except ports that connect to the ARM1026EJ-S processor. These ports use a portion of the wrapper chain on the ARM1026EJ-S processor. If the ARM methodology is used, then the ETM10RV macrocell test vectors are created using both the ETM10RV and a portion of the ARM1026EJ-S core wrapper. Figure 4.2 shows the ETM10RV wrapper interface.

There are four types of wrapper cell, described in the following sections: