HARMONY(4) | Device Drivers Manual (hppa) | HARMONY(4)

# 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 with a maximum 48000 Hz sample rate, and has 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 a 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

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

# HISTORY

Support for `harmony` first appeared in OpenBSD 3.3. It was ported to NetBSD 1.6 by Chuck Silvers.

# CAVEATS

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

May 15, 2022 | NetBSD 11.0