PERMISSIONS CHECKING FOR DATA PROCESSING INSTRUCTIONS

摘要

A data processing system having a processor (12) and a target device (40) processes decorated instructions (i.e. an instruction having a decoration value). A device of the data processing system such as the processor (12) sends transactions to the target device (40) over a system interconnect (14). The transactions include an indication of an instruction operation, an address associated with the instruction operation, a decoration value (601 ) (i.e. a command to the target device to perform a function in addition to a primary function of the executed instruction), and access permissions associated with the address. The target device (40) (e.g. a memory with functionality in addition to storage functionality) determines whether a decoration operation specified by the decoration value is permissible based on the received access permissions. The target device (40) performs the decoration operation if appropriate permissions exist.