A data processing system having debugging circuitry and a method for
operating the data processing system is provided. In the system, a
processor has a cache memory and is coupled to a system bus. An
instruction is received which indicates an effective address. The
instruction is executed and it is determined if the effective address
results in a hit or a miss in the cache. If the effective address results
in a hit, data associated with the effective address is provided from the
cache to the system bus without modifying a state of the cache. The
instruction allows real-time debugging circuits to be able to view the
current value of one or more variables in memory that may be hidden from
access due to cache hierarchy without modifying the value or impacting
the current state of the cache.