Interface Protocols

Protocols – Uses for communication with devices

Communication are different types 

  • Intra – Communication between two devices within device

                       Ex: I2C, SPI

  • Inter – Communication between two devices 

                       Ex: CPU & Microcontroller, UART

  1. Simplex Duplex - One way communication ex: Fm
  2. Half Duplex - Two-way communication but only receive or transfer at a time ex: walkie talkie
  3. Full Duplex - Two-way communication at a time ex: Mobile
  4. Synchronous - Will use clock signal to send or receive any data
  5. Asynchronous - Need to maintain same frequency while transferring and receiving using clock signal

UART – Universal Asynchronous Receive and Transmitter

  • We will transfer data using serial communication 
  • It will use two wires Rx & Tx
  • It is synchronous communication to transfer data
  • Parity Bit is used to check whether data is correct or not at receiver end
  • Even Parity – No of ‘1’ in data even
  • Odd Parity – No of ‘1’ in data odd
  • Uses Baud rate of 115200 bps, 96000 bps

Cons:

  • When Baud Rate differs will be mismatch in data
  • It will used only short-range communications 

SPI – Serial Peripheral Interface

It uses Master & Slave terminology and uses parallel communication
  • MISO - Master In, Slave Out
  • MOSI - Master Out, Slave In
  • SCLK - Serial Clk (Always Master generates the clock)
  • CS/SS - Chip select/ Slave Select
  • CPOL - Clock Polarity - Decides data Format
  • Cphase - Clock Phase - Decides when bits need to be transferred by tx & when bits need to be received by Rx




We can connect one master to multiple slaves, but we cannot use multiple master

Pros:
  • No stop bits & start bits, So data transferred will be faster 
  • Higher data transfer rate
  • Full Duplex
  • Without interruption transfer the data
Cons:
  • We cannot sure whether data transferred proper or not
  • Single master
  • No Acknowledgement pin

I2C – Inter Integrated Circuit
  • Half duplex communication
  • Serial communication
  • Synchronous mode

It has unique address
Start – 7 or 10bitaddress – 1 bit read/write – 1bit Ack – 8 bits data – 1bit ack – 8 bits data –– 1bit Ack – 1bit stop
 



Comments

Post a Comment

Popular posts from this blog

Q format representation

Image
Most of the developers who are working on the multimedia domain are not familiar with the below questionnaire😏. What is q format? Why do we require q formats in DSP processors? Advantages of q format? Disadvantages of q format? Once you get to know about q format, then your daily working practice will be quiet easier to understand about code. Q format is a representation of integers for processing the CPU or DSP. when a CPU lacks the floating-point unit in a processor then q format is used to enable the rational number processing with hardware arithmetic unit(ALU). Floating-point operations take so much time and performance-wise also worse when compared with fixed-point. So most companies prefer fixed-point processors only. We represent fixed-point numbers as  Qn  format, Here  n  represents no.of fractional bits. Other way of representation is  Qm.n m - no of Integer bits used to represent a decimal number. n - no of fractional bits used to represents a fractional part  Q format bits
Read more

BeamForming

Image
B eamforming,which is playing a key role in modern era for evaluation of 5G technology. It's also know as  spatial filtering  used in sensor arrays for directional signal transmission or reception.This can be achieved by combining the elements in an antenna array in such way that signals have to taken from particular angles.  Beamforming can be used in both transmission end or reception end. Lets take one example fig(1).for clear understanding of what beamforming & how it helps When a navigator under water needs to send a signal from certain distance from hydrophone to ship,Then if he sends the signal directly to receiver in straight direction ,it will not reach them.He has to maintain some angle of elevation.    In the above example, When arriving from -45° the signal reaches the left hand microphone first, when arriving from perpendicular to the array (called broadside) the signal reaches each microphone at the same time and when from +45° the right hand microphone receives t
Read more

Binary representation of numbers

 Binary representation of numbers In this we will learn how to represent a number in Binary format, Octa, Hex formats 1 - 0001               6 - 0110               11 - 1011 (B) 2 - 0010               7 - 0111               12 - 1100 (C) 3 - 0011               8 - 1000               13 - 1101 (D) 4 - 0100               9 - 1001               14 - 1110 (E) 5 - 0101              10 - 1010 (A)     15 - 1111 (F) Ex 1: Represent 56 in binary format        56 - (2^5) * 1 + (2^4) * 1 + (2^3) * 1 +  (2^2) * 0 + (2^1) * 0 + (2^0) * 0                  - (111000) Ex 2: Represent -56 in binary format There are multiple ways to represent negative numbers in binary format 1) With sign magnitude, Generally      sign bit - 1 -> Negative numbers     sign bit - 0 -> Positive numbers     3 - 00000011    -3 - 10000011 2) Using 2's complement -47 -> 1) binary representation of Positive 47 - 101111            2) pad the bits based on format -> 00101111            3) Invert the bits -> 110
Read more