Communication refers to the interaction between two devices in embedded system. It can be between computer and microcontroller or between two microcontrollers.
Data Transfer
There are many techniques , different data transfer technique are used in
different situations. Some example of data transfer is
• Simple parallel transfer‐Used to transfer 8, 16, and 32
etc bits of data in the same time.
• Asynchronous
Serial Transfer (USART) –It is an old but still in use mode of serial
communication uses only 2 lines (+1 additional line for GND).
• SPI
- Serial Peripheral Interface ‐ It is a standard mode of
communication between different
• USB
-
A very advance,
high speed and complicated serial Bus used in PCs to connect almost anything to
it.
Classification
Modes of Data Transfer can be divided into two types:
1. PARALLEL TRANSFER In this mode a number of bits (say 8,16
or 32) are transferred at a time. Thus they require as many electrical line as
the number of bits to be transferred at once.
2. SERIAL TRANSFER In this mode only one bit is transfer at
once. So to transfer 8 bits, 8 cycles are required.
Modes of Data Transfer can also be divided into
1. SYNCHRONOUS TRANSMISSION‐.
2. ASYNCHRONOUS TRANSMISSION
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Baud Rate
Baud Rate is a measurement of transmission speed in asynchronous communication. Devices that allow the communication must all agree on a single speed of information its unit is 'bits per second'.
Transmission
|
Advantages
|
Disadvantages
|
Asynchronous
|
Simple & Inexpensive
|
High Overhead
|
Synchronous
|
Efficient
|
Complex and
Expensive
|
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Different Communication
Techniques
Simplex : one sided communication like radio
Half duplex: like walkie talkie
Full duplex : video conferencing
