I2S interface Introduction

I2S interface Introduction
I. I2S Protocol Introduction
The I2S protocol is developed by Philips as the audio data transmission protocol. The Protocol consists of three data lines:
1. sclk: serial clock. frequency = 2 * sampling frequency * Number of sampling digits.
2. WS: select the field (Channel) to switch between left and right channels. Ws = sampling frequency (FS ).
A, 1 (left channel)
B, 0 (right channel)
3. SD: Serial Data (Binary Complement) (MSB ---> LSB: data is transmitted from the highest bit to the lowest Bit)

 

Figure acoustic/Voice Signal
Ii. AEC
AEC (Acoustic Echo cancellor) echo cancellation requires specific algorithms to achieve echo elimination (echo elimination uses signal processing methods ). The speaker output sound is transmitted to mic as a way of Echo generation.

Iii. I2S sampling and processing process
Analog Signal ---> sampling ---> quantization ---> encoding ---> digital signal

Iv. nequest sampling theorem
When the sampling frequency fs is greater than or equal to twice the maximum frequency of the analog signal, the analog signal can be restored without losing sight.

I2S interface Introduction