Global Sources
EE Times-India
Stay in touch with EE Times India
EE Times-India > Interface

An initial look at USB Type-C

Posted: 09 Feb 2015     Print Version  Bookmark and Share

Keywords:USB Type-C 

Actually you typically needed to add expansion cards for all sorts of things, such as modems and sound cards and suchlike. The problem was that adding an expansion card to an ISA (Industry Standard Architecture) bus-based system was a non-trivial matter. (ISA was the precursor to the Peripheral Component Interconnect (PCI) standard.) In order to add a card, you had to remove the cover to your PC, set a number of switches and/or jumpers on the card to configure it, and then insert the card into a free slot in the system.

What? Did you think I forgot to mention replacing the cover on the PC? If only things were that simple. Generally speaking, this was the time when your problems really started. Once the system was powered up, you would typically have to load the software driver for this device from a floppy disk. Then you would have to juggle a limited number of interrupt request lines to ensure that the resources you had selected weren't already being used by another device. Adding a simple modem card, for example, could take hours—and that was if you really knew what you were doing; for average users the whole thing was a nightmare of confusion and despair!

USB 1.0 to 3.1
In order to address all of the connector-related issues presented on the previous page, a group of seven companies got together in 1994. These companies—who we should all thank profusely—were Compaq, DEC, IBM, Intel, Microsoft, NEC, and Nortel. What they wanted to was to make it fundamentally easier to connect external devices to computers. In order to do this, they set about addressing the usability issues of existing interfaces and simplifying the software configuration of any devices connected to the computer, as well as permitting greater bandwidths for external devices.

The result, of course, was the Universal Serial Bus, or USB for short. USB 1.0 was released in January 1996, but there were a number of "glitches" and "gotchas," with the result that few USB 1.0 devices actually made it to the market. USB 1.1 was released in September 1998. This release fixed the problems in the 1.0 version and was the earliest version to be widely adopted.

The first time I personally saw a USB connector was on the back of a tower computer I purchased in the summer of 1998. Unfortunately, these connectors didn't work for some time until a software patch became available. On the bright side, this really didn't affect me too much because—at that time—I didn't have any USB-enabled devices to plug into the computer anyway. Of course, this was soon to change, and it wasn't long before USB products of all shapes and sizes were to be found strewn all around my office.

Now, if there's one thing we know for sure, it's that we have an ever-increasing demand to move more and more data around. USB 1.x specified data rates of 1.5 Mbps (megabits per second; known as Low Speed) and 12 Mbps (known as Full Speed). These bandwidths were OK for less-demanding applications—like mice and keyboards and even printers and scanners—but they were painfully slow when it came to transferring larger chunks of data.

This led to the USB 2.0 specification, which was formally standardized by the USB-IF toward the end of 2001. In addition to adding new transfer mechanisms and other techno-weenie details, USB 2.0 also augmented the existing speed variants with a higher data transfer rate of 480 Mbps (High Speed), which was a 40-fold increase over the Full Speed maximum bandwidth offered by USB 1.x.

The advantages associated with USB are difficult to overstate. I don't know about you, but I can no longer envisage a world without things like USB memory sticks (I find it hard to believe that an RS-232-based memory stick would have the same appeal). The fact that USB-enabled devices are hot-pluggable has saved the human race countless hours that would otherwise have been spent fruitlessly powering computers down and up again. Also, when you connect a new USB device to your computer, it can either use an existing driver or it will automatically download the required driver over the Internet.

 First Page Previous Page 1 • 2 • 3 • 4 • 5 • 6 Next Page Last Page

Comment on "An initial look at USB Type-C"
*  You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.


Go to top             Connect on Facebook      Follow us on Twitter      Follow us on Orkut

Back to Top