Glossary of terms
Atom - a component of a VLIW instruction word, or molecule. Conceptually, an atom is similar to an instruction for a RISC processor. A key difference is that a VLIW processor does not execute individual atoms by themselves but always as part of an entire molecule.
Binary instruction - generally speaking, an instruction for a computer, as encoded in a format understandable by the computer (as opposed to being readable by humans).
Cache - Generally a small chunk of fast memory that sits between either 1) a smaller, faster chunk of memory and a bigger, slower chunk of memory, or 2) a processor and a bigger, slower chunk of memory. This is to provide a bridge from something that's comparatively very fast to something that's comparatively slow.
Chipset - usually refers to Northbridge and Southbridge chips used in building a computer motherboard.
CISC - Intel x86 chips are CISC chips because of the complexity of the instruction set.On the other side of the coin, you have RISC chips that use a reduced instruction set. RISC chips split big operations into lots of simple, tiny instructions that are processed very quickly.
CMOS - the predominant integrated circuit technology used in semiconductors. Compared to its alternatives, CMOS consumes less power while enabling high speeds.
Code - what computer scientists call the collection of computer instructions that constitute an application program separate from the data.
Code MorphingTM software - Code Morphing software translates the ones and zeros of the application program instructions into a more efficiently executed set of instructions for the Crusoe processor.
Commit atom - an atom specific to the CrusoeTM VLIW engine that commits a set of pending changes (to memory or to registers) in a single operation.
Compiler - software that translates a program written in a high-level programming language (COBOL, C, and others) into binary instructions.
CPU (Central Processing Unit, also called "processor") - the active part of the computer where all computation (such as addition) is performed. Today, the CPUs of almost all computers are contained on a single chip.
Crusoe - for consumers, the Crusoe name will mean long battery life, full compatibility, and high performance. The Crusoe brand stands for a family of smart microprocessors from Transmeta intended for use in Mobile Internet Computers.
DDR memory - a new type of SDRAM memory that is both higher performance and lower power than standard SDRAM, making it appropriate for the latest portable devices. "DDR" is short for "Double Data Rate," referring to the high speed at which this memory transfers data.
Full Internet experience - the ability to get access to all the data and details found on the world wide web, in the full form intended by the web site. This can only be done with a computer that is fully Internet compatible
Gated store buffer - a hardware mechanism in the Crusoe VLIW engine that holds writes to memory until those writes are either committed (via a commit atom ) or discarded (via a rollback atom). The "gated" refers to the notion of the write operations being held behind a fence until they are ready to be released.
Information appliance - a computing device designed specifically for accessing the Internet - "browsing the web" - but not designed for running PC applications.
Instruction set architecture - in essence, the programmer-visible part of how a processor works, comprising the instructions that the processor implements, the set of registers available, and so on.
Internet appliance, Internet device - any computer device used to access information on the Internet.
Internet compatible - a computer that is x86 PC compatible and can also be compatible with the rich data types found on the World Wide Web, such as Macromedia Flash, RealAudio, and various streaming video formats.Often compatibility with web data comes from loading a plugin for an internet browser. Compatibility is often a combination of the PC system architecture, the operating system (such as Microsoft Windows or Linux), and the ability to execute x86-plugin applications.
Load-and-protect atom - an atom that loads a data value from a memory location, while at the same time "protecting" that memory location from being overwritten. The Code Morphing software uses load-and-protect atoms to generate faster code.
LongRunTM - LongRun is a power management technique found in the Crusoe processor model TM5400. LongRun works by monitoring the precise performance level needed by an application, and then by dynamically adjusting the Crusoe processor's operating speed and voltage to match that need. With LongRun, Crusoe can make adjustments while the application is running, thereby making the most efficient use of power, for the longest battery life.
Low-power processor - a low-power processor is a microprocessor that consumes less than five watts when running applications, and in cases where the processor does not need to be actively running, has a sleep mode that consumes less than 25 milliWatts of power.
MHz (megahertz) - a measure of frequency, commonly used to describe the speed of electronic devices. A device said to run at 600 MHz, for example, performs some operation (such as executing an instruction) 600 million times per second.
Micro-ops - a term commonly used to refer to operations performed internally by out-of-order superscalar processors; typically, one or more micro-ops are performed for each instruction that the processor executes.
Mobile Internet Computer - a computer that uses a Mobile Internet Processor to achieve compatibility with the x86 PC system architecture, long battery life, and high performance.
Mobile Internet Processor - a microprocessor that simultaneously has x86 compatibility, low power, and sufficient performance to run demanding web-based applications such as streaming video.
Mobile Linux - a version of Linux created by TransmetaTM and distributed to its OEM customers for mobile Internet devices such as web pads and handheld clients that do not contain a hard drive. The principal enhancements for Mobile Linux are in the areas of power management and in the reduction of the memory footprint.
Molecule - a VLIW instruction word containing multiple atoms, which the hardware executes in parallel. The current Crusoe processors support 64- and 128-bit-long molecules containing two to four atoms each. When the hardware processes a molecule, it executes all atoms in the molecule in parallel, meaning the current Crusoe processors can perform up to four operations per cycle.
Northbridge - the interface between the CPU and memory, and the interface between the CPU and Input/Output busses. In prior years, the Northbridge was a separate chip. With the Crusoe processor, the DRAM controllers to memory and the PCI Input/Output busses have been integrated onto the same piece of silicon as the CPU.
OEM - Original Equipment Manufacturer - This acronym is used to denote equipment that is sold to other companies or resellers for integration into systems. For example, a chip manufacturer may sell an OEM chip in bulk quantities and no manual or cables with the promise that it will go into full systems.
Optimization - a process whereby a program is made to run faster by removing redundant instructions, reordering instructions, or replacing "slow" instruction sequences with faster ones.
Out-of-order machine - a processor architecture that internally executes instructions in an order different from that in which they occur in the program being executed. This is the traditional, hardware-intensive approach to speeding up old programs on new processors.
PCI bus - a hardware interface that connects a processor to user input/output devices (for example, graphics controller, USB controller, LANs, or modems). The Crusoe processor model TM3120 and Crusoe processor model TM5400 include on-chip PCI controllers.
Plugin - a term for a small computer program, usually x86 compatible, that can extend the functionality of a web browser, such as Netscape or Microsoft Internet Explorer.
Register - fast temporary storage areas located in the processor. All computation (such as addition) in a processor is typically done inside registers.
RISC (Reduced Instruction Set Computer) - a computer architecture that reduces chip complexity by using simpler instructions than a CISC (Complex Instruction Set Computer). An x86 processor is generally regarded as a CISC.
Rollback atom - an atom specific to the Crusoe VLIW hardware that discards a set of pending changes (to memory or to registers) in a single operation. In effect, the opposite of a commit atom.
ROM (Read Only Memory) - a memory chip that persistently stores instructions and data, even when power is turned off. A Flash ROM is a type of ROM that can actually be reprogrammed with different contents.
SDRAM (Synchronous DRAM) - a type of dynamic RAM memory chip that has been widely used in the latter part of the 1990s.
Shadow register - a mechanism in the Crusoe VLIW engine that enables fast commit and rollback operations. To perform a commit operation, the processor copies each normal, or "working", register into its corresponding shadow register. For a rollback, the copy is done in the reverse direction. In effect, each shadow register contains a "backup" copy of its corresponding working register, allowing the working register to be overwritten with (possibly speculative) data.
Smart Microprocessor - a microprocessor that is capable of learning about an application while it is running and is able to use that knowledge to improve behavior. Crusoe uses learning to both improve the performance and to lower the power of applications as they run.
Software optimized execution - the ability to use software to improve the characteristics of a computer program while it is running.
Southbridge - a chip that interfaces between the PCI Input/Output bus and the many individual interfaces on a computer, such as keyboard, mouse, and hard disk.
Speculation - the notion of performing an operation speculatively, that is, before knowing whether the result of the operation will actually be needed. The Crusoe processor supports speculation via an innovative combination of hardware and software.
Superscalar - a CPU architecture that can execute more than one instruction in one clock cycle. Unlike a VLIW processor, a superscalar processor must first analyze (at not insignificant hardware cost) all incoming instructions to decide whether they can indeed be legally executed in the same cycle.
TM3120 - the Crusoe processor targeted for Internet access devices like web pads and handheld computers.
TM5400 - the Crusoe processor model that is targeted at ultra-light (less than four pounds) mobile PCs.
Transistor - A three-terminal semiconductor device for amplification, switching, and detection, typically containing two rectifying junctions and operating so that the current between one pair of terminals controls the current between the other pair, one terminal being common to input and output.Translation - in the context of Crusoe processors, a sequence of VLIW molecules that perform the same function as a given sequence of x86 instructions.
Translation cache - in a Code Morphing system, an area of memory that holds previously made translations ready for execution.
VLIW (Very Long Instruction Word) - a CPU architecture in which the processor executes long instruction words (molecules) consisting of several instructions (atoms) each. Unlike superscalar or out-of-order processors, a VLIW does not need to analyze whether instructions can be executed in parallel, since the molecule already explicitly encodes that information. This reduces hardware cost and enables higher processor speeds.
Web pad - a type of Internet appliance that consists of a large LCD screen and a touchpad for user input.
x86 (also 80x86) - refers to the Intel 8086 CPU family used in PCs, which includes the Pentium family. The majority of PC software applications is written specifically for the x86 microprocessor architecture.
x86 compatible - a term commonly used in the computer industry to signify the format and interfaces for a computer software application that will execute correctly on a platform originally known as an IBM-compatible PC.