Data processor instruction system for grouping instructions with or without a common prefix and data processing system that uses two or more instruction grouping methods

摘要

A system for instructing a data processor, the system including an instruction root having an operation selection field for selecting an operation to be performed by said data processor and an instruction prefix. The instruction prefix has a field selected from the group of a conditional execution field for selecting a condition under which a data processor will perform said selected operation, an operand length modification field for modifying the selected operation so as to be performed on an operand having a different length, an instruction group field for selecting a length of an instruction group that includes the instruction root, and a prefix length selection field for selecting a length of said instruction prefix. A data processor system responsive to this instruction system is also disclosed. An instruction system for statically grouping instructions without using an instruction prefix is also disclosed.