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

ExperimenterUK
Sun Mar 01 2015, 07:06 AM
@Anupam Biswas..post all you have done in the GSM forum
Sat Feb 28 2015, 02:51 PM
Anupam Biswas
I am doinga project on gsm based home automation.I have done alittle study about at commands.I am using Atmel 89c51 with yhe gsm module.I am unable to receive any message via the module.The simulation is done on proteus and i am using a virtual terminal.Can anyone please help me?Thanks in advance.
Tue Feb 24 2015, 12:47 AM
MrCurious
is Stat a global variable too? you reference it in Chan's "disk_status" function.
Sat Feb 21 2015, 09:10 PM
Harikumar
കൊള്ളാം
ExperimenterUK
Fri Feb 20 2015, 06:28 AM
@sugikz.. I have asked Ajay about it, he'll soon sort it out
Thu Feb 19 2015, 12:22 PM
sugikz
"Sorry no bots allowed! You entered two different email addresses. Please enter a valid email address in the two fields provided"
Thu Feb 19 2015, 12:21 PM
sugikz
this are the problem notice box;
Thu Feb 19 2015, 12:20 PM
sugikz
yes, i still got stuck on email problem, i've used gmail, yahoo, and told some friends of mine to sign up on the site, but they face the same problem as iam,
Thu Feb 19 2015, 05:48 AM
sjeeva
hi, is any doing a project on raspberry pi
Thu Feb 19 2015, 05:48 AM
sjeeva
hi

Downloads

Comments

raamchandran
Mon Mar 02 2015, 11:20 AM
ABiDAEV
Sat Feb 28 2015, 11:31 PM
arunkollam
Wed Feb 25 2015, 05:28 AM
sugikz11
Wed Feb 25 2015, 04:23 AM
Buhari
Sun Feb 22 2015, 03:16 PM
Jarvis_v3
Sat Feb 21 2015, 02:00 AM
Sontoloyo
Thu Feb 19 2015, 12:50 PM
catty
Thu Feb 19 2015, 12:20 PM

Online

Guests: 47, Members: 0 ...

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

Members: 37590
Newest member: raamchandran
Forum Activity
ABiDAEV Avatar
Posted By ABiDAEV
Sun Mar 01 2015, 11:42 AM
Thanks for sharing, but can you please update the ...
sankalp_s Avatar
Posted By sankalp_s
Thu Feb 26 2015, 09:27 PM
What are you trying to make ?ExperimenterUKsir i w...
ExperimenterUK Avatar
Posted By ExperimenterUK
Thu Feb 26 2015, 12:58 AM
We seem to be moving away from the original projec...
ajay_bhargav Avatar
Posted By ajay_bhargav
Wed Feb 25 2015, 02:02 PM
You will need a 64 bytes buffer that will be writt...
PsySc0rpi0n Avatar
Posted By PsySc0rpi0n
Wed Feb 25 2015, 09:24 AM
I've already read that tutorial and almost all oth...
ajay_bhargav Avatar
Posted By ajay_bhargav
Wed Feb 25 2015, 04:56 AM
brightness control is going to be tough job as you...
ajay_bhargav Avatar
Posted By ajay_bhargav
Wed Feb 25 2015, 04:36 AM
I've already read that tutorial and almost all oth...
sankalp_s Avatar
Posted By sankalp_s
Tue Feb 24 2015, 07:18 PM
The attached code is for up to 16 LEDs.Just point ...
sankalp_s Avatar
Posted By sankalp_s
Tue Feb 24 2015, 07:16 PM
sankalp_s Avatar
Posted By sankalp_s
Tue Feb 24 2015, 07:12 PM