XVS-440-10MPI-1-1AD Eton encoder
When silicon technology allows a wider implementation to be built (with more execution units), the previous generation of compilers will not be able to run on a wider implementation because the encoding of binary instructions depends on the number of execution units in the machine.
Transmeta solves this problem by including a binary-to-binary software compiler layer (called code morphing) in its Crusoe implementation of the x86 architecture. This mechanism is advertised as essentially recompiling, optimizing, and translating x86 opcode into the CPU’s internal machine code at run time. Thus, the Transmeta chip is internally a VLIW processor, effectively separated from the x86 CISC instruction set it executes.
Intel’s Itanium architecture (and others) addresses backward compatibility issues with more general mechanisms. In each multiopcode instruction, a bit field is assigned to represent a dependency on a previous VLIW instruction in the program instruction stream. These bits are set at compile time, relieving the hardware of the burden of computing this dependent information. Encoding this dependency information in the instruction stream allows a broader implementation to issue multiple non-dependent VLIW instructions in parallel per cycle, while a narrower implementation will issue a smaller number of VLIW instructions per cycle.
Another perceived flaw in the VLIW design is code bloat that occurs when one or more execution units have no useful work to do and therefore must execute no-action NOP instructions. This happens when there are dependencies in the code and the instruction pipeline must be allowed to exhaust before subsequent operations can continue.
As the number of transistors on a chip has increased, the significance of the obvious shortcomings of VliWs has diminished. The VLIW architecture is gaining popularity, especially in the embedded systems market, where processors can be customized for applications on a system on a chip.
XV-102-A5-35MQR-10
XV-102-A0-35MQR-10
SW-GALILEO
XV-102-B8-35TQR-10-PLC
XV-102-B5-35TQR-10-PLC
XV-102-B3-35MQR-10-PLC
XV-102-B0-35MQR-10-PLC
XV-102-B2-35TQR-10
XV-102-B0-35TQR-10
MEMORY-SD-A1-S
MEMORY-CF-A1-S
XV-303-70-B00-A00-1B
XV-303-70-B00-A00-1C
XV-303-10-C00-A00-1C
XV-303-10-B00-A00-1C
XV-303-15-C00-A00-1E
XV-303-15-C00-A00-1D
XV-303-15-CE2-A00-1C
XV-303-15-CE0-A00-1C
XV-303-15-C02-A00-1C
XV-303-15-C02-A00-1B
XV-303-15-C00-A00-1C
XV-303-15-C00-A00-1B
XP-503-21-A10-A00-1B
XP-503-10-A10-A00-1V
XP-503-15-A10-A00-1V
XV-102-H3-35TQRL-10
XV-102-H4-35TQRL-10
DPM-MC2
XV-442-57CQB-1-10
8922-RB-IS
MPB2-TP
MP3010
XVS-430-10MPI-1-10
XV-440-12TSB-1-10
XV-430-12TSB-1-10
MPB1-TP
