CMI9738 Datasheet, PDF (23/36 Pages) List of Unclassifed Manufacturers – Integrated Multi-channel AC97

Record Gain Registers (Index 1Ch) (R/W)
CMI 9738
Integrated Multi-channel AC‘97
Reg Name D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 Default
1Ch Record Gain Mute X X X GL3 GL2 GL1 GL0 X X X X GR3 GR2 GR1 GR0 8000h
Each step corresponds to 1.5 dB. 22.5dB corresponds to 0F0Fh and 000Fh respectively. The MSB
of the register is the mute bit. When this bit is set to 1 the level for that channel(s) is set at ∞ dB.
The default value is 8000h, which corresponds
to 0 dB gain with mute on.
Mute
0
0
1
Gx3...Gx0
1111
0000
xxxxx
Function
+22.5 dB gain
0 dB gain
−∞ dB gain
General Purpose Register (Index 20h) (R/W)
Reg
Name
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 Default
20h General Purpose X X X X X X X X LPBK X X X X X X X 0000h
Bit
LPBK
Function
ADC/DAC loopback mode
Powerdown Control/Status Register (Index 26h) (R/W)
Defaul
Reg Name D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
t
Powerdown
26h
X PR6 PR5 PR4 PR3 PR2 PR1 PR0 X X X X REF ANL DAC ADC 000Xh
Ctrl/Stat
This read/write register is used to program powerdown states and monitor subsystem readiness.
The lower half of this register is read only status, a 1 indicating that the subsection is “ready”.
Ready is defined as the subsection able to perform in its nominal state. When this register is written
the bit values that come in on AC-link will have no effect on read only bits 0-7.
When the AC-link “Codec Ready” indicator bit (SDATA_IN slot 0, bit 15) is a 1 it indicates that the
AC-link and AC ‘97 control and status registers are in a fully operational state. The AC ‘97
Controller must further probe this Powerdown Control/Status Register to determine exactly which
subsections, if any, are ready.
C-MEDIA Electronics Inc.
6F, 100, Sec. 4, Civil Boulevard, Taipei, Taiwan, R.O.C. 106
TEL: [phone] FAX: [phone] E-mail:[e-mail]
Revision Date Apr./2002
Revision 1.1