Comment 33 for bug 1487168
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| Raymond (superquad-vortex2) wrote Re: [Emulated AD1980 AC97 inside Virualbox 5.0, playback] volume slider problem | #33 |
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1b1ed1a
(Get the code!)
” Mono Volume Register (Index 06h) Reg No.Name
D15D14D13D12D11
Default 06h
Mono Volume
MVM X X X X X X X X X MV5 MV4 MV3 MV2 MV1 MV0 8000h
*Refer to Table II for examples. This register controls the Mono output volume and mute bit. The volume register contains five bits, generating 32 volume levels with 31 steps of 1.5 dB each. Because AC ’97 defines 6-bit volume registers, to maintain compatibility, whenever the D5 bit is set to “1,” their respective lower five volume bits are automatically set to “1” by the codec logic. On readback, all lower five bits will read “1s” whenever this bit is set to “1.” All registers not shown and bits containing an X are assumed to be reserved.
MV[5:0] Mono Volume Control. The least significant bit represents 1.5 dB. This register controls the output from 0 dB to a maximum attenuation of 46.5 dB.
MVM Mono Volume Mute. When this bit is set to “1,” the channel is muted.