Patent ID: 6895494

Claim:
The structure of a subpipelined translation embodiment providing binary compatibility between a base architecture and migrant architecture of a VLIW architecture comprising: a VLIW architecture comprising a base architecture and a migrant architecture and having a base execution mode and a migrant execution mode; an instruction fetch unit for simultaneously fetching from memory a group of a plurality of instructions, each such group forming a fetch packet, said instruction fetch unit assigning each fetch packet an operating mode in dependence upon the execution mode at the time the request was made to the memory for the fetch packet; a shared datapath by both the base and migrant architectures for parsing said base architecture mode and migrant architecture mode fetch packets into execute packets of instructions within said fetch packet that can be executed simultaneously; a base architecture control circuit for dispatching execute packet instructions having a base execution mode; a migrant architecture control circuit for dispatching execute packet instructions having a migrant execution mode; a base architecture decode connected to said shared datapath and said base architecture control circuit for decoding an execute packet in said base mode and generating a corresponding machine word; a migrant architecture decode connected to said shared datapath and said migrant architecture control circuit for decoding an execute packet in said migrant mode and generating a corresponding machine word; a multiplexer having at least three inputs and one machine word output wherein a first input is the machine word output of said migrant architecture decode, a second input is the machine word output of said base architecture decode and a third input receiving a no operation instruction machine word, said multiplexer choosing in dependence upon the operating mode of said fetch packet; and execute hardware connected to said multiplexer for executing execute packet instructions on execution units corresponding to said machine word chosen by said multiplexer.