7.5. CDP

CDPs normally execute in a single cycle. Like all other instructions, nCPMREQ is driven LOW to signal when an instruction is entering the Decode and then the Execute stage of the pipeline:

Figure 7.5 shows a CDP that is canceled due to the previous instruction causing a Data Abort. The CDP instruction enters the Execute stage of the pipeline, and is signaled to execute by CPPASS. In the following phase CPLATECANCEL is asserted. This causes the coprocessor to terminate execution of the CDP instruction, and for it to cause no state changes to the coprocessor.

Figure 7.5. ARM922T late canceled CDP

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