7.1. About the coprocessor interface

The ARM946E-S processor fully supports the connection of on-chip coprocessors through the external coprocessor interface and supports all classes of coprocessor instructions.

The interface differs from the basic ARM9E-S coprocessor interface. To ease integration of an external coprocessor, the interface from the ARM946E-S processor to the coprocessor has been pipelined by a single clock cycle as shown in Figure 7.1.

Figure 7.1. Pipeline stages

This ensures that ARM946E-S interface outputs, which otherwise arrive late in the clock cycle, are driven out directly from registers to the external coprocessor. This significantly eases the implementation task for an external coprocessor.

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