# Asynchronous Transmission

Synchronous data transmission requires:
A clock signal and two lines
1 of 11
Asynchronous data transmission requires:
Start and Stop bits and 1 line
2 of 11
Fast transmission but requires 2 lines
3 of 11
Only 1 line used but slow transmission
4 of 11
What is the purpose of the start and stop bits?
To designate the beginning and end of a string of bits
5 of 11
What is the purpose of parity bit(s)?
To check that the data has been transmitted correctly
6 of 11
How do Even and Odd parity systems work?
The amount of logic 1s are even (even parity) and odd (odd parity) when the data is correct
7 of 11
Issues with parity bits:
Longer transmission, sometimes won't detect errors.
8 of 11
How do 2 bit systems work?
Each parity bit checks a nibble of data
9 of 11
How do 4 bit systems work?
Each parity bit checks 4 bits, with overlap between each parity bit
10 of 11
At what point does error correction become possible?
When there is 4 bit or 5 bit parity, it is possible to locate the area where an error occurs.
11 of 11

## Other cards in this set

### Card 2

#### Front

Start and Stop bits and 1 line

#### Back

Asynchronous data transmission requires:

### Card 3

#### Front

Fast transmission but requires 2 lines

### Card 4

#### Front

Only 1 line used but slow transmission

### Card 5

#### Front

To designate the beginning and end of a string of bits