STA310 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'STA310' PDF : 90 Pages View PDF
STA310
coming vocal channels, V1 and V2.
An additional mode is added ( AC3_KARAMODE =
3) to allow multi-channel reproduction. In this case,
the downmix specified by the AC3_DOWNMIX and
AC3_DUALMODE registers is applied.
The following table summaries the different modes:
Value Mode
Comment
0 Aware Left = L + clev*M + slev*V1, Right = R +
clev*M + slev*V2
1
Not used
2
Not used
3 Multicha Consider bitstream as multi-channel:
nnel Perform downmix according to
DOWNMIX and DUALMODE registers
4 Capable Do not reproduce V1, V2: Left = L +
clev*M, Right = R + clev*M
5
Reproduction V1 only: Left = L + clev*M
+ 0.707*V1, Right = R + clev*M +
0.707V1
6
Reproduction V2 only: Left = L + clev*M
+ 0.707*V2, Right = R + clev*M +
0.707V2
7
Reproduction V1, V2: Left = L + clev*M
+ V1, Right = R + clev*M + V2
Left = Output Channel,
Right = Output Channel, L, R, M, V1, V2 = Input
Channels (coded in Dolby Digital karaoke bitstream),
clev = Center Mix Level (value provided in the bit-
stream),
slev = Surround Mix Level (value provided in the bit-
stream). For further information ref. to annex C of
ATSC standard “Digital Audio Compression (AC-3)”.
AC3_DUALMODE
Dual downmix
7
6
5
4
3
2
1
0
Address: 0x6E
Type: R/W
Software Reset: NC
Hardware Reset: UND
Description
This register allows additional downmix to be set
when in 2/0 output mode or when receiving a “Dual
mode” incoming bitstream (example: A disk with 2 dif-
ferent languages on channel 1 and channel 2). In the
following table, channel 1 and 2 represent the output
channels after downmix performed with
AC3_DOWNMIX.
This register enables Mono downmix when
AC3_DOWNMIX = 2 and AC3_DUALMODE = 3.
Value
Description
0 Output as Stereo
1 Output Channel 1 on both output L/R
2 Output Channel 2 on both output L/R
3 Mix Channel 1 and 2 to monophonic and
output on both L/R
AC3_DOWNMIX
Downmix
7
6
5
4
3
2
1
0
Address: 0x6F
Type: R/W
Software Reset: NC
Hardware Reset: UND
Description:.
Value
0
1
2
3
4
5
6
7
Description
2/0 Dolby Surround (LT, RT)
1/0 (C)
2/0 (L, R)
3/0 (L, C, R)
(L, R, S)
3/1 (L, C, R, S)
2/2 (L, R, LS, RS - Dolby Phantom Mode
3/2 (L, C, R, LS, RS)
Note: in notation, 3/2 represents 3 front speakers and
2 surround speakers.
AC3_STATUS0
65/90
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