N900 Hardware Audio Codec

The Audio codec encodes and decodes audio.

Hardware

The audio codec is a low-power 4 channel codec From TI.

It is connected to the CPU using I2C and the MCBSP serial digital audio interface.

Software

User

The audio codec is driven by pulseaudio, through ALSA. The ALSA interface is usually not exposed in maemo 5 - adding:

pcm.real {
	type hw
	card 0
}

ctl.real {
	type hw           
	card 0
}

to /etc/asound.conf enables a hardware device. Stopping pulseaudio may be required to use this.

Kernel

The codec is driven by a driver built into the kernel.