?
Solved

what is a uart and how do I identify it on mobo

Posted on 2011-10-28
4
Medium Priority
?
212 Views
Last Modified: 2012-05-12
what is a uart and how do I identify it on mobo
0
Comment
Question by:now2010
4 Comments
 
LVL 88

Expert Comment

by:rindi
ID: 37043660
It is the chip for serial rs 232 type interfaces. Often it is a 16550, 8250, gd75232d chip etc. Normally the chip will be close to the actual ports, so look at those chips more closely.
0
 
LVL 93

Expert Comment

by:nobus
ID: 37049196
0
 
LVL 1

Accepted Solution

by:
diablobob earned 2000 total points
ID: 37129796
UARTs (Universal Asynchronous Receiver Transmitter) are serial chips on your PC motherboard (or on an internal modem card). The UART function may also be done on a chip that does other things as well. On older computers like many 486's, the chips were on the disk IO controller card. Still older computer have dedicated serial boards.

The UART's purpose is to convert bytes from the PC's parallel bus to a serial bit-stream. The cable going out of the serial port is serial and has only one wire for each direction of flow. The serial port sends out a stream of bits, one bit at a time. Conversely, the bit stream that enters the serial port via the external cable is converted to parallel bytes that the computer can understand. UARTs deal with data in byte-sized pieces, which is conveniently also the size of ASCII characters.

As for locating it on the motherboard generally the UART is going to be a long thin chip.although sometimes it is a square chip. Like Rindi said it will most likely be in the proximity of the the serial port

Say you have a terminal hooked up to your PC. When you type a character, the terminal gives that character to its transmitter (also a UART). The transmitter sends that byte out onto the serial line, one bit at a time, at a specific rate. On the PC end, the receiving UART takes all the bits and rebuilds the (parallel) byte and puts it in a buffer.

Along with converting between serial and parallel, the UART does some other things as a byproduct (side effect) of its primary task. The voltage used to represent bits is also converted (changed). Extra bits (called start and stop bits) are added to each byte before it is transmitted. Voltage Wave shapes'' for details. Also, while the flow rate (in bytes/sec) on the parallel bus inside the computer is very high, the flow rate out the UART on the serial port side of it is much lower. The UART has a fixed set of rates (speeds), which it can use, at its serial port interface.
0
 

Author Closing Comment

by:now2010
ID: 37157512
Sorry for the delay, thank you.
0

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article may be useful for troubleshooting your PC. Power Supply - no lights or fans running If you have no lights or fans running then either you power is bad, turned off (check switch) or the power supply needs to be replaced. That's a r…
Employees depend heavily on their PCs, and new threats like ransomware make it even more critical to protect their important data.
The viewer will learn how to successfully create a multiboot device using the SARDU utility on Windows 7. Start the SARDU utility: Change the image directory to wherever you store your ISOs, this will prevent you from having 2 copies of an ISO wit…
The viewer will learn how to successfully download and install the SARDU utility on Windows 7, without downloading adware.
Suggested Courses
Course of the Month12 days, 17 hours left to enroll

578 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question