Some basic I2S concepts

In digital audio datasheet, we often see concepts such as 256fs, 384fs, 32 kHz, and 44.1 kHz mclk. Generally, three pins are used as communication interfaces in the digital audio chip: bclk, adclrc, and dout. Now let's make a summary.

1. Sampling Rate: 32 kHz, 44.1 kHz, 48 khz, 96 kHz: the audio sampling rate, the higher the sound quality. In 256fs, "FS" indicates audio sampling frequency (adclrc). Here, the audio control line uses adclrc to sample 32 kHz, 44.1 kHz, 48 kHz, and 96 kHz. Adclrc controls the left-right channel control indication. We can imagine that the period of adclrc is the period of audio sampling. Here, the audio chip mclk can be obtained through 256 (FS) × 48k (HZ. The sampling rate is determined by the adclrc foot of I2S. It is determined by the mclk and adclrc you provide as xxxfs xxx = f (mclk)/F (adclrc ). While bclk has a certain ratio to mclk, such as wm8775,
Bclk = mclk/4.