5.1. About the coprocessor interface

The ARM7EJ-S processor supports the connection of coprocessors through the coprocessor interface and supports all classes of coprocessor instructions.

Coprocessors determine the instructions they must execute using a pipeline follower in the coprocessor. As each instruction arrives from memory, it enters both the ARM pipeline and the coprocessor pipeline. The coprocessor determines when an instruction is being fetched by the ARM7EJ-S processor, so that the instruction can be loaded into the coprocessor, and the pipeline follower advanced.

To ease integration of a coprocessor, the interface from the ARM7EJ-S processor to the coprocessor has been pipelined by a single clock cycle. This provides an optimized interface that significantly eases the implementation task for a coprocessor.

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