The main control chip is the core component of the motherboard or hard disk. It is the bridge between various devices and the brain that controls the operation of the devices. In the motherboard, two chips are important. One is Nanqiao chip, which controls the expansion slot, USB interface, serial port, parallel port, 1394 interface, VGA interface, etc. it is mainly responsible for the connection between external interface and internal CPU. The other is Beiqiao chip, which controls the type and model of CPU, bus frequency of motherboard, memory type, capacity, graphics card, etc.

The main uses of the master chip are as follows:

1. Load and run the operating system (commonly known as firmware);

2. Decode all kinds of files, such as txt files, picture files, music files and so on;

3. The most important thing is audio decoding. The main control chip decompresses the compressed audio in the player. This belongs to hardware decompression.

In addition, there is something called DAC, namely digital to analog converter, which converts the digital signal decompressed in the third point above into analog signal. Many MP3 player's DAC is not independent, but embedded into the main control chip. When we buy, we buy those products that make audio DAC independent, such as Meizu's M6 and M3.