General Purpose Input/Output (GPIO) is a generic pin on a chip whose behavior (including whether it is an input or output pin) can be controlled (programmed) by the user at run time.
GPIO pins have no special purpose defined, and go unused by default. The idea is that sometimes the system integrator building a full system that uses the chip might find it useful to have a handful of additional digital control lines, and having these available from the chip can save the hassle of having to arrange additional circuitry to provide them. For example, the Realtek ALC260 chips (audio codec) have 8 GPIO pins, which go unused by default. Some system integrators (Acer Inc. laptops) employing the ALC260 use the first GPIO (GPIO0) to turn on the amplifier used for the laptop's internal speakers and external headphone jack.
Famous quotes containing the words output, input, purpose and/or general:
“Lizzie Borden took an axe
And gave her mother forty whacks;
When she saw what she had done,
She gave her father forty-one.”
—Anonymous. Late 19th century ballad.
The quatrain refers to the famous case of Lizzie Borden, tried for the murder of her father and stepmother on Aug. 4, 1892, in Fall River, Massachusetts. Though she was found innocent, there were many who contested the verdict, occasioning a prodigious output of articles and books, including, most recently, Frank Spierings Lizzie (1985)
“Family life is not a computer program that runs on its own; it needs continual input from everyone.”
—Neil Kurshan (20th century)
“I dont like to be idle; in fact, I often feel somewhat guilty unless there is some purpose to what I am doing. But spending a few hoursor a few daysin the woods, swamps or alongside a stream has never seemed to me a waste of time.... I derive special benefit from a period of solitude.”
—Jimmy Carter (James Earl Carter, Jr.)
“Any general statement is like a cheque drawn on a bank. Its value depends on what is there to meet it.”
—Ezra Pound (18851972)