1. A data processor arranged to execute software to emulate an instruction-handling processor, the software having at least an instruction preparation stage and an instruction execution stage, the software being operable: fine to carry out said instruction preparation stage in respect of a group of two or more instructions to generate a group of prepared instructions; and then to carry out said instruction execution stage in respect of said group of prepared instructions, so that the completion of said instruction execution stage in respect of each of said prepared instructions occurs serially in an instruction order.