harmony(4) - NetBSD Manual Pages

Command: Section: Arch: Collection:  
HARMONY(4)           NetBSD/hppa Kernel Interfaces Manual           HARMONY(4)

harmony -- CS4215/AD1849 audio interface
harmony* at gsc? audio* at harmony?
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).
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
hppa/ioctl(2), audio(4), hppa/gsc(4), hppa/intro(4), rnd(4)
Support for harmony first appeared in OpenBSD 3.3. It was ported to NetBSD 1.6 by Chuck Silvers.
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 10.99 May 15, 2022 NetBSD 10.99
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