Insight - How Memory Card works

Table of Contents:

  1. Insight - How Memory Card works
  2. Internal Structure
  3. Memory Chip & Controller
  4. Electrical Connections
The Secure Digital (SD) Card or more commonly known as memory cards are small size storage devices that are specially designed to store and transfer data from audio and video consumer electronic devices like digicam, cell phones, voice recorders etc. They are known as secure digital card because they include a copyright protection mechanism that complies with the security of the SDMI (Secure Digital Music Initiative) standards. In this mechanism, a mutual authentication and encryptions are used to protect the card content from illegal usage.  
 

How SD Memory card works

 
A commonly used memory card is shown in the above image. The notch in the tip right corner of the card helps to identify the right way of attaching with the device. As per the standards, each SD card is formatted with a File Allocation Table (FAT) file system, which allows every operating system to access the files in that system. 
 

SD Memory Card Pins

  
The SD card communicates with the host (PC/Laptop) based on an advanced nine pin interface which is designed to operate at a low voltage. The nine pins, as shown in the above image, are for Clock, Command, Data and Power.
 

Comments (9)

good job! 

Submitted by ucsam123 on Sun, 20/11/2011 - 15:25.

good job!
 

SPI                          

Submitted by georgedb on Sun, 18/12/2011 - 17:17.

SPI                                                                            

An interesting addition might be, that communication with an SD card is through the, widely known, SPI-protocol / standard. It's visible in the image on the last step of this insight, but it isn't mentioned anywhere.

GOOD ACHIEVMENT

Submitted by ICYIMANISHATSE JE... on Thu, 16/02/2012 - 22:55.

GOOD ACHIEVMENT

nice job

Submitted by dineshk7 on Thu, 01/03/2012 - 11:09.

nice job

please provide details of

Submitted by karthikkarthik on Mon, 10/09/2012 - 21:01.

please provide details of mirco sd card

 

nice job  

Submitted by link2mani on Mon, 17/09/2012 - 15:53.

nice job

 

please give me the c code for

Submitted by PEARL1234 on Wed, 20/02/2013 - 21:47.

please give me the c code for storing the sound in a microcontroller.

the sound is stored in a smart card ,but i am not able to write the code for it.

waiting for reply?

 

 

 

 

 

great......... do briefly

Submitted by premkvp on Mon, 18/03/2013 - 07:01.

great......... do briefly with code...

i request admin to update a

Submitted by ravihc1985 on Fri, 10/05/2013 - 16:36.

i request admin to update a sample code for interfacing with pic controller.