STA309A View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

STA309A

Multi-channel digital audio processor with DDX®

STMicroelectronics 

Registers

STA309A

7.2.33

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.

AUTO2 - Automode™ bass management2 (0x20)

D7

SUB

1

D6

RSS1

0

D5

RSS0

0

D4

CSS1

0

D3

CSS0

0

D2

D1

D0

FSS

AMBMXE

AMBMME

0

0

0

Table 56. AMBMME bit

Bit RW RST

Name

0

RW

0

AMBMME

Description

0: Automode bass management mix disabled

1: Automode bass management mix enabled

Table 57. AMBMXE bit

Bit RW RST

Name

1

RW

0

AMBMXE

Description

0: Automode bass management crossover disabled

1: Automode bass management crossover enabled

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 2nd 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.

40/67

Doc ID 13855 Rev 4

Share Link: