In telecommunication and computer science, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent together, on a link with several parallel channels. Serial communication is used for all long-haul communication and most computer networks, where the cost of cable and synchronization difficulties make parallel communication impractical. Serial computer buses are becoming more common even at shorter distances, as improved signal integrity and transmission speeds in newer serial technologies have begun outweigh the parallel bus's advantage of simplicity (no need for serializer and deserializer, or SerDes) and to outstrip its disadvantages (clock skew, interconnect density). The migration from PCI to PCI Express is an example.
Contents |
Standard teletype systems evolved as an automated telegraphy system called telex. Originally, a rotating mechanical commutator (a rotating switch) was started by a "start bit". The commutator would distribute the other bits to set relays that would pull on solenoids which would cause the mechanism to print a figure on paper. The routing was automated with rotary electromechanical dialing systems like those used in early telephone systems. When computers became commonplace, these serial communication systems were adapted using I/O devices called serial ports that used UARTs. The development of communication hardware had a deep continuing impact on the nature of software and operating systems, both of which usually arrange data as sequences of characters.
Integrated circuits are more expensive when they have more pins. To reduce the number of pins in a package, many ICs use a serial bus to transfer data when speed is not important. Some examples of such low-cost serial buses include SPI, I²C, UNI/O, and 1-Wire.
The communication links across which computers—or parts of computers—talk to one another may be either serial or parallel. A parallel link transmits several streams of data (perhaps representing particular bits of a stream of bytes) along multiple channels (wires, printed circuit tracks, optical fibres, etc.); a serial link transmits a single stream of data.
At first sight it would seem that a serial link must be inferior to a parallel one, because it can transmit less data on each clock tick. However, it is often the case that serial links can be clocked considerably faster than parallel links, and achieve a higher data rate. A number of factors allow serial to be clocked at a greater rate:
In many cases, serial is a better option because it is cheaper to implement. Many ICs have serial interfaces, as opposed to parallel ones, so that they have fewer pins and are therefore less expensive.
Serial communication is a term used to described system used for telecommunications, as well as certain technologies used for computing. When using serial communication, only one bit is transferred at a time, for example over a communication channel or computer bus. This is different to parallel communication, where several bits are sent at the same time. Many computer networks, as well as many lines where data is transferred over a long distance use serial communication.
   | Serial interfaces listing (with pinouts) - RS-232 and other serial ports and interfaces pinouts listing @ pinouts.ru |
| | Serial Interface Tutorial for Robotics - How to Build a Robot Tutorial - Society of Robots |
| | Wireless RS-232 - Benefits of Wireless RS-232 - Technology - Digi International |
|
|
Wikis
Quiz
Search
