Lecture 17 Flashcards
Serial Communication 1
Serial communications
single line that is varied over time to transfer multiple bit of information
Parallel communications
Multiple lines (also varying over time that can transfer multiple bits of information
The process of how device 2 knows when the next bit of information is going to be valid
Synchronisation
What is Communication synchronisation?
When the receiving device can determine when one bit ends and the other ends.
What is Synchronous communication?
When a separate clock signal is used to notify the receiver when the next bit can be read.
The 3 points of a working Asynchronous communication
The receiver “just knows”, based on
- A known (expected signal rate.
- The transition in the data stream (when 0 changes to 1 etc.)
- Special markers in the signal (Start bit, Stop bit)
Bi-directional communication
Information can flow in both directions.
What is DMA?
Direct Memory Access.
Data transfer without the use of the CPU.
Traits of UART
Point-to-point
Asynchronous
Traits of I2C
Bus
Synchronous
SPI
Bus
Synchronous
Meaning of Asynchronous
no clock signal
Point-to-Point
Connects two device with each other. (data can also be sent both ways at same time)
The 3 TTL signal levels
TX,RX and Ground
The standard bit rates
1200, 9600, 19200, 115200
