Transmeta's molecular approach

Very Long Instruction Word (VLIW) coding is notoriously difficult and, as its name implies, takes its instructions in chunks.

A Crusoe word can be 64 or 128bits long and contain up to four RISC-like instructions. Transmeta refers to Crusoe's words and sub-instructions as "molecules and atoms".

These are fed into a relatively simple VLIW engine consisting of a floating-point unit, two integer units, a memory load/store unit, and a branch unit.

Each atom in a molecule has to go to a different functional unit, so that an entire word can be processed at the same time. Processing is thus implicitly parallel.

The morph engine's job is to pack words so that this is done as efficiently as possible. Instructions are dealt with in strict running order - avoiding the out-of-order circuitry of standard x86 processors.