Method for optimally encoding a set of instruction codes for a digital processor having a plurality of instruction selectable resource types and an associated optimized set of instruction codes

摘要

A method of assigning unique instruction codes to instructions in an instruction set is disclosed. Such an encoded instruction set is also disclosed. Instructions are grouped according to the particular resources used, where all of the instructions in a group have one or more resource types in common. The position of the highest order active bit in the code is used to identify which resource group a particular instruction belongs to. Instructions in a resource group reserve the same number of bits to identify the specific resources to be used, and no more bits are reserved than required. The remaining unassigned bits are used to encode particular command codes. When such an encoded command is decoded, the resource group is identified by determining the highest order active bit in the instruction. This information is used to determine which bits in the instruction are command bits and which are resource-identifying bits. The specific resource information is extracted and used to select the designated resources to be used in executing the command. This encoding scheme eliminates wasted bits in instructions and thereby increases the number of instructions which can be implemented.