Registers
STA309A
40/67
Doc ID 13855 Rev 4
Channels 1-6 must be arranged via channel mapping (registers CnIM) if necessary in the
following manner for this operation:
Channel 1: left
Channel 2: right
Channel 3: left surround
Channel 4: right surround
Channel 5: center
Channel 6: LFE.
7.2.33
AUTO2 - Automode™ bass management2 (0x20)
Setting the AMBMME bit enables the proper mixing to take place for various preset bass
management configurations. Setting the AMBMXE bit enables the proper crossover filtering
in biquad #7 to take place. The crossover for bass management is always 2
nd
order
(24 dB/oct) and the crossover frequency is determined by register bits PREEQ.XO[2:0].
All configurations of Dolby
®
bass management can be performed in the IC. These different
configurations are selected as they would be by the end-user.
The Automode bass management settings utilize channels 1-6 on the Mix #1 engine,
Channels 1-6 biquad #6, and channels 1-2 on the mix #2 engine in configuration #2. These
functions cannot be user programmed while the bass management Automode is active.
Not all settings are valid as some configurations are unlikely and do not have to be
supported by Dolby
®
specification.
Automatic crossover settings are provided or custom crossovers can be implemented using
the available programmable biquads.
D7
D6
D5
D4
D3
D2
D1
D0
SUB
RSS1
RSS0
CSS1
CSS0
FSS
AMBMXE
AMBMME
1
0
0
0
0
0
0
0
Table 56.
AMBMME bit
Bit
RW
RST
Name
Description
0
RW
0
AMBMME
0: Automode bass management mix disabled
1: Automode bass management mix enabled
Table 57.
AMBMXE bit
Bit
RW
RST
Name
Description
1
RW
0
AMBMXE
0: Automode bass management crossover disabled
1: Automode bass management crossover enabled