Firmware

[attachment=18167]

Origin of the term
Ascher Opler coined the term "firmware" in a 1967 Datamation article.[1] Originally, it meant the contents of a writable control store (a small specialized high speed memory), containing microcode that defined and implemented the computer's instruction set, and that could be reloaded to specialize or modify the instructions that the central processing unit (CPU) could execute. As originally used, firmware contrasted with hardware (the CPU itself) and software (normal instructions executing on a CPU). It was not composed of CPU machine instructions, but of lower-level microcode involved in the implementation of machine instructions. It existed on the boundary between hardware and software, thus the name "firmware".
Later[when?] application of the term broadened to include any type of microcode, whether in writable control store or read-only control store.


Firmware as of 2011
Today, in some circles, the word firmware has evolved to sometimes even denote application-level programs stored in NAND flash or NOR flash memory (such as in mobile phones and similar products). However, a more fundamental definition would still be fixed or semi-fixed data in a hardware device. This may include ROM and/or PLA structures for microcode and other data in a processor implementation as well as the low level machine code stored in ROM or flash memory running on that processor (i.e. many products use several levels of firmware). Microcode and other data in an application-specific integrated circuit (ASICs) would also fit that definition very well. The same could be said about programmable logic devices which may have configuration data stored either as internal fuses, in a ROM, or in a flash memory (used much the same way as a ROM or EPROM).


Computer peripherals
Most computer peripherals are themselves special-purpose computers. While external devices (printers, scanners, cameras, USB drives,...) have firmware stored internally, modern graphics cards and peripheral expansion cards often have parts of the firmware loaded by the host system at start-up, as this provides greater flexibility. Such hardware may therefore fail to function fully until the host computer has "fed" it the requisite firmware, typically via a specific device driver (more exactly: via a start-up subsystem within a device driver package).


Consumer products
As of 2010 most modern portable music players support firmware upgrades. Some companies use firmware updates to add new playable file formats (encodings); iriver added the Vorbis format this way, for instance. Other features that may change with firmware updates include the GUI or even the battery life. Most mobile phones have a Firmware Over The Air firmware upgrade capability for much the same reasons; some may even be upgraded to enhance reception or sound quality, illustrating the fact that firmware is used at more than one level in complex products (in a CPU-like microcontroller versus in a digital signal processor in this particular case).

Automobiles
Since 1996 most automobiles have employed an on-board computer and various sensors to detect mechanical problems. As of 2010 modern vehicles also employ computer-controlled ABS systems and computer-operated Transmission Control Units (TCU). The driver can also get in-dash information while driving in this manner, such as real-time fuel-economy and tire-pressure readings. Local dealers can update most vehicle firmware.