Discussion in "General help Guidance and Discussion" started by    RUSHI D    Apr 28, 2009.
Tue Apr 28 2009, 04:13 AM
#1
hi frnz...!

can u pls list down d differences between SPI and I2C protocols...

regards
rushi d.
Tue Apr 28 2009, 05:50 AM
#2
I2C =>less no. of pins only one line for data transfer
SPI=>two lines required for data transfer
I2C is slower than SPI.
Tue Apr 28 2009, 07:14 AM
#3
thanx shyam...

but i want detailed differences like if we r compairing their speeds den mention d max speeds they can achieve

any more difference...

regards
rushi d.
Tue Apr 28 2009, 07:32 AM
#4
There are a lot of difference from the protocol point of view. But Hardware wise it same as mentioned by shyam.

1. In I2C lot of s/w manipulation has to be done. where as in SPI programmer need to handle only SS pin if SPI is used between multiple ics.

2. I2C can reach only till 384kbps based on CCLK. Whereas SPI can go till CCLK/4. i.e., if CCLK=12MHz, Then SPI speed is 3MHz.

3. There are atleast 30-40 situation which programmer is suppose to handle in I2C for effective and efficient communication. where as in SPI only SS is suppose to be managed and data is supposed to be placed in SPDAT.

4. In SPI since both the MOSI(Master Out Slave In) and MISO(Master In Slave Out) uses a single buffer care should be taken to transfer the data.

5. I2C can be used in a situation where shrinking of the pcb is more important than speed and SPI is vice-versa

 RUSHI D. like this.
Tue Apr 28 2009, 07:41 AM
#5
I2C can go upto 4Mhz SPI can go upto 70Mhz
 RUSHI D. like this.
Tue Apr 28 2009, 07:42 AM
#6
thanx ajaz 4 ur reply

but i did not get 3rd pt..

can u explain..?
Tue Apr 28 2009, 07:57 AM
#7
He mens to say that, incase of I2C programmer has to take care of right sequence of data transfer on bus like address, start, stop, ack, nak etc...
where as in case of SPI just SS (slave select) is to be managed and data read/write is done from SSPDAT register.

these names may vary from controller to controller
Tue Apr 28 2009, 12:47 PM
#8
k got it...
thanx ajay
Tue Apr 28 2009, 06:10 PM
#9
A very valuable tool to discovering what things mean and what things do is the Google search engine.

If you type into this search engine the phrase "SPI interface", your first website shown is:
http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus

This is a pretty good description of the SPI interface, and some of what it can do...

Likewise, if you type in "I2C interface", you get this website:
http://en.wikipedia.org/wiki/I%C2%B2C

Give it a try, and see for yourself...

Hope this helps,

Get Social

Information

Powered by e107 Forum System

Conversation

Thu Jan 19 2017, 08:42 PM
abhays
Hi...i have made a circuit for interfacing PT100 with LM358 whose temperature is shown on the LCD...But the temperature is not getting incresed slowly ..a small change directly increses the temp...can any one help me
Thu Jan 19 2017, 04:27 PM
roba
send me alarm clock simulation using proteus software
Mon Jan 16 2017, 03:15 PM
Rutuja
How can we read notepad file using random acess file
Fri Jan 06 2017, 06:18 AM
muhammad Umar
i need cd4047 library file for protious please help me i s
ExperimenterUK
Wed Jan 04 2017, 09:01 PM
@Emin what is your site user name ?
Tue Jan 03 2017, 11:16 PM
Emin
Emin: I'm already a member since 2012 and entered repeatedly during period. But now it is impossible and obtaining a new registration is also failed. The same error message specifying that two e-mails i entered are different!. In fact thaey are the same. Now, what will be happen, what is your solution? Thanks..
Tue Jan 03 2017, 11:15 PM
Emin
I'm already a member since 2012 and entered repeatedly during period. But now it is impossible and obtaining a new registration is also failed. The same error message specifying that two e-mails i entered are different!. In fact thaey are the same. Now, what will be happen, what is your solution? Thanks..
Sun Jan 01 2017, 03:14 PM
Manoranjana Chary
Write an embedded program of increment and decrement in LCD connected to two keys of int1 and int0. Can u please send me the code for this as fast as possible because i need to submit it in college kindly
ExperimenterUK
Sat Dec 31 2016, 06:28 PM
Happy New Year everyone
ExperimenterUK
Sat Dec 31 2016, 06:27 PM
Please post questions in the forum, the chat box is for chat

Downloads

Comments

jmunjr
Tue Jan 17 2017, 06:25 PM
sarfrosh92
Sun Jan 15 2017, 09:18 AM
Deepakvaishu
Wed Jan 11 2017, 10:25 AM
rana_jee773
Sat Dec 10 2016, 11:22 AM
[email protected]
Thu Dec 08 2016, 11:02 AM
Jonathan.kei
Mon Nov 21 2016, 04:30 PM
AVRuser1
Sun Nov 20 2016, 06:07 PM
JaguarPaw
Thu Nov 17 2016, 07:44 PM

Online

Guests: 39, Members: 0 ...

most ever online: 182184
(Members: , Guests: 182184) on 06 Aug 2010: 05:37 AM

Members: 37797
Newest member: jmunjr
Forum Activity
ExperimenterUK Avatar
Posted By ExperimenterUK
Sat Jan 21 2017, 06:48 AM
I should say that setting up CODE::BLOCKS (or any...
Deepakvaishu Avatar
Posted By Deepakvaishu
Sat Jan 21 2017, 04:42 AM
Thanks a lot..I will try with SDCC, or else I will...
ExperimenterUK Avatar
Posted By ExperimenterUK
Fri Jan 20 2017, 09:35 PM
SDCC is a compiler, it turns text (source code) in...
sankalp_s Avatar
Posted By sankalp_s
Fri Jan 20 2017, 04:40 PM
Thank you so much sir for your great response.. :)...
Deepakvaishu Avatar
Posted By Deepakvaishu
Fri Jan 20 2017, 08:47 AM
Is the steps of programmming of keil and sdcc sa...
ExperimenterUK Avatar
Posted By ExperimenterUK
Fri Jan 20 2017, 12:50 AM
Looks like you are using a demo version of Keil.Ei...
ExperimenterUK Avatar
Posted By ExperimenterUK
Fri Jan 20 2017, 12:31 AM
The original reverse24displayloop:was a bit messy....
sankalp_s Avatar
Posted By sankalp_s
Thu Jan 19 2017, 05:52 PM
Thank you sir.. understood the logic..But reverse ...
Deepakvaishu Avatar
Posted By Deepakvaishu
Thu Jan 19 2017, 09:48 AM
my code is working now..But the next problem which...
Deepakvaishu Avatar
Posted By Deepakvaishu
Thu Jan 19 2017, 04:50 AM
I am using serial interrupt for RFID card reader,...