harmony(4) - NetBSD Manual Pages

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HARMONY(4)           NetBSD/hppa Kernel Interfaces Manual           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 Multime-
     dia 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 maxi-
     mum 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 accu-
     racy 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.

NetBSD 10.0                      May 15, 2022                      NetBSD 10.0