If you are implementing a system that does not include any external coprocessors, you must tie both CPA and CPB HIGH. This indicates that no external coprocessors are present in the system. If any coprocessor instructions are received, they take the undefined instruction trap so that they can be emulated in software if required. The internal coprocessor, CP14, can still be used.

The coprocessor outputs from the ARM7TDMI processor are usually left unconnected but these outputs can be used in other parts of a system as follows:.