January 26, 2003 HARMONY 4 hp700

### NAME

harmony - CS4215/AD1849 audio interface

### SYNOPSIS

harmony* at gsc? audio* at harmony?

### DESCRIPTION

The harmony device uses the Crystal Semiconductor CS4215 16-Bit Multimedia Audio Codec or Analog Devices AD1849 SoundPort(R) Stereo Codec chip to implement the audio device interface described in audio(4). This device is found on most HP PA-RISC workstations. The harmony has a maximum precision of 16 bits and has a stereo input and stereo output.

On HP 9000/712 models harmony also provides two additional channels for an add-on card with two fax/voice modems.

One of the hardware registers reflects the state of the CHI bus that is used to communicate with the codec and thus being sampled at a low accuracy secondary frequency (such as timeout(9)) produces poor quality random bit stream that is fed into the entropy pool of rnd(4).

### MACHINES

An incomplete list of machines that feature harmony audio:

- 712/*
- 715/*
- 725/*
- 735/*
- 755/*
- B132L[+], B160L, B180L+
- C100, C110, C132L, C160[L], C180, C200, C240, C360
- J200, J210[XC], J280, J282, J2240

### SEE ALSO

ioctl(2), audio(4), gsc(4), intro(4), rnd(4)

### HISTORY

Support for harmony first appeared in OpenBSD3.3. It was ported to NetBSD1.6 by Chuck Silvers.

### CAVEATS

To trigger entropy collection CHI bus has to be programmed into the data mode that happens once a single buffer of data has been played or recorded.