Browse Definitions :
Definition

UART (Universal Asynchronous Receiver/Transmitter)

Contributor(s): Ken Conway and Michael DeHaan

A UART (Universal Asynchronous Receiver/Transmitter) is the microchip with programming that controls a computer's interface to its attached serial devices. Specifically, it provides the computer with the RS-232C Data Terminal Equipment ( DTE ) interface so that it can "talk" to and exchange data with modems and other serial devices. As part of this interface, the UART also:

  • Converts the bytes it receives from the computer along parallel circuits into a single serial bit stream for outbound transmission
  • On inbound transmission, converts the serial bit stream into the bytes that the computer handles
  • Adds a parity bit (if it's been selected) on outbound transmissions and checks the parity of incoming bytes (if selected) and discards the parity bit
  • Adds start and stop delineators on outbound and strips them from inbound transmissions
  • Handles interrupt s from the keyboard and mouse (which are serial devices with special port s)
  • May handle other kinds of interrupt and device management that require coordinating the computer's speed of operation with device speeds

More advanced UARTs provide some amount of buffering of data so that the computer and serial devices data streams remain coordinated. The most recent UART, the 16550, has a 16-byte buffer that can get filled before the computer's processor needs to handle the data. The original UART was the 8250. If you purchase an internal modem today, it probably includes a 16550 UART (although you should ask when you buy it). According to modem manufacturer US Robotics, external modems do not include a UART. If you have an older computer, you may want to add an internal 16550 to get the most out of your external modem.

This was last updated in February 2011

Continue Reading About UART (Universal Asynchronous Receiver/Transmitter)

Join the conversation

1 comment

Send me notifications when other members comment.

Please create a username to comment.

why are the real teachers almost never inside the classrooms?
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • Whistleblower Protection Act

    The Whistleblower Protection Act of 1989 is a law that protects federal government employees in the United States from ...

  • smart contract

    A smart contract, also known as a cryptocontract, is a computer program that directly controls the transfer of digital currencies...

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

SearchSecurity

  • Payload (computing)

    The term payload, when used in the context of networking or telecommunications, is the data carried inside of a packet (or other ...

  • access control

    Access control is a security technique that regulates who or what can view or use resources in a computing environment.

  • ethical hacker

    An ethical hacker, also referred to as a white hat hacker, is an information security expert who systematically attempts to ...

SearchHealthIT

SearchDisasterRecovery

  • virtual disaster recovery

    Virtual disaster recovery is a type of DR that typically involves replication and allows a user to fail over to virtualized ...

  • tabletop exercise (TTX)

    A tabletop exercise (TTX) is a disaster preparedness activity that takes participants through the process of dealing with a ...

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a data center.

SearchStorage

  • storage at the edge

    Storage at the edge is the collective methods and technologies that capture and retain digital information at the periphery of ...

  • Flash Storage

    Flash storage is any type of drive, repository or system that uses flash memory to keep data for an extended period of time.

  • optical disc

    An optical disc is an electronic data storage medium that can be written to and read from using a low-powered laser beam.

Close