Difference between revisions of "Serial line"
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* [[asynchronous serial line]]s, in which the format is self-[[clock]]ing (i.e. the start location of each character can be inferred from the data stream), and | * [[asynchronous serial line]]s, in which the format is self-[[clock]]ing (i.e. the start location of each character can be inferred from the data stream), and | ||
* [[synchronous serial line]]s, where each character starts immediately after the previous one, and is therefore not self-clocking | * [[synchronous serial line]]s, where each character starts immediately after the previous one, and is therefore not self-clocking | ||
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| + | Both serial line [[protocol]]s requires two signal levels: idle (mark, high), and asserted (space, low). (The polarity is a legacy from telegraphy, where the line was held high in order to show that the line was not broken, and that the transmitter was functional.) | ||
{{semi-stub}} | {{semi-stub}} | ||
[[Category: Communication Basics]] | [[Category: Communication Basics]] | ||
Revision as of 14:11, 21 March 2020
A serial line is a means of transmitting data in bit serial fashion, often over a communication link such as a telephone line. There are two principal forms:
- asynchronous serial lines, in which the format is self-clocking (i.e. the start location of each character can be inferred from the data stream), and
- synchronous serial lines, where each character starts immediately after the previous one, and is therefore not self-clocking
Both serial line protocols requires two signal levels: idle (mark, high), and asserted (space, low). (The polarity is a legacy from telegraphy, where the line was held high in order to show that the line was not broken, and that the transmitter was functional.)
