I2S

[Myauk]

Where can I read the principles of I2S?
I found it in some Audio CODEC applications.
I do not know the reason why it uses three different clocks Master
Clock, Bit Clock and Data Alignment Clock.
I understand the Data Alignment Clock generally the the left and right
audio signals in digital format alternately on a single line in serial.
But still why are there bit clock and master clock.
Where can I find out about all this theories as well as other
requirements for a complete Full Duplex system of inter chip
communication.
Regards

 

[me]

Where can I read the principles of I2S?
I found it in some Audio CODEC applications.
I do not know the reason why it uses three different clocks Master
Clock, Bit Clock and Data Alignment Clock.
I understand the Data Alignment Clock generally the the left and right
audio signals in digital format alternately on a single line in serial.
But still why are there bit clock and master clock.
Where can I find out about all this theories as well as other
requirements for a complete Full Duplex system of inter chip
communication.
Regards

Google is a good place to start...

 

[Eeyore]

Where can I read the principles of I2S?

Google ? Wikipedia ?

I found it in some Audio CODEC applications.
I do not know the reason why it uses three different clocks Master
Clock, Bit Clock and Data Alignment Clock.
I understand the Data Alignment Clock generally the the left and right
audio signals in digital format alternately on a single line in serial.
But still why are there bit clock and master clock.

All the audio DACs and ADCs I can think of need only L/R_clock ( word clock )
and bit_clock.
http://en.wikipedia.org/wiki/I2S

What do you actually want to *know* ?

Graham

 

[Myauk]

All the audio DACs and ADCs I can think of need only L/R_clock ( word clock )
and bit_clock.
http://en.wikipedia.org/wiki/I2S

What do you actually want to *know* ?

Graham

I am studying about the Wolfson WM8776.
http://www.wolfsonmicro.com/support/whitepaper/audio/
I generally understand that an audio file contains audio information
with different sample rates.
So L/R clock defines the periods in which Left and Right Audio Signals
in PCM format would be agreed to trasmit and receive between the Master
and Slave Devices, then the bit_clock is just a reference to determine
the sample rate at which the PCM signal is transmitted, and then Master
Clock, I hope, is just for infromation.

Correct me if I am wrong.
I am reading as much as I could but I need help for faster learning.
Thanks

 

[Eeyore]

I am studying about the Wolfson WM8776.
http://www.wolfsonmicro.com/support/whitepaper/audio/
I generally understand that an audio file contains audio information
with different sample rates.
So L/R clock defines the periods in which Left and Right Audio Signals
in PCM format would be agreed to trasmit and receive between the Master
and Slave Devices, then the bit_clock is just a reference to determine
the sample rate at which the PCM signal is transmitted, and then Master
Clock, I hope, is just for infromation.

Correct me if I am wrong.
I am reading as much as I could but I need help for faster learning.

You seem to have it pretty much correct.

Bit clock is simply used to clock in each bit of serial data.

I've yet to see a system that uses M_clk.

Graham

 

[Myauk]

You seem to have it pretty much correct.

Bit clock is simply used to clock in each bit of serial data.

I've yet to see a system that uses M_clk.

Graham

Thanks
There are other DAC ICs that uses M_Clk such as CS4351; they all use
four lines for data communication: Bit, Master, Left/Right clocks!

From wikipedia, I understand that I2C uses only two lines serial clock,

and serial data, and I 2S uses three: Bit clock line, Word clock line
(also called word select line), And at least one multiplexed data line.

But where does that Master Clock come from?
I am reading through the wolfson white papers to understand more about
it.
Regards

 

[Eeyore]

But where does that Master Clock come from?

Dare I say, the master clock oscillator ! All the others are just divided down
from it.

Graham

 

[Myauk]

Dare I say, the master clock oscillator ! All the others are just divided down
from it.

Graham

Yes, now I understand about it.
The fundamental concept require only three types, the bit, the L/R
clock signals and the data signal.
But they are just inventing new concept of Master clock for a few
reasons.
Here, see this,
http://www.wolfsonmicro.com/uploads/documents/en/MCLK_fs_whitepaper_Rev12.pdf.
Now I can figure out the general concept of Data transimssion and
receiving for Audio Systems.
Thank you for your colloborative suggestions.

Regards