CONFIDENTIAL INFORMATION Rev. 1.2

May 4, 2020

SABRE9006ADatasheet

ESS TECHNOLOGY, INC. 237 South Hillview Drive, Milpitas, CA 95035, USA Tel (408) 643-

8800 • Fax (408) 643-8801

8

AUTOMUTE

AUTOMUTE is used to achieve the absolute maximum signal-to-noise ratio on an idle channel.

o

In PCM serial mode, AUTOMUTE will become active once the audio data is continuously below the threshold set by

<Register Automute_lev>, for a length of time defined by 2096896/(<Register#9> x DATA_CLK) Seconds.

o

In SPDIF mode, the AUTOMUTE will become active once the audio data is continuously below the threshold set by

<Register Automute_lev>, for a length of time defined by 2096896/(<Register#9> x (64 x fs) Seconds, where fs is the

SPDIF sampling rate.

o

In the DSD Mode, AUTOMUTE will become active when

any 8 consecutive values in the DSD stream have as many 1’s

and 0’s for a length of time defined by 2096896/(<Register Automute_time> x DATA_CLK) Seconds. The following table

summarizes the conditions.

Mode

Detection Condition

Time

PCM

Data is continuously lower than

<Register Automute_lev >

2096896/(<Register Automute_time > x DATA_CLK)

SPDIF

Data is continuously lower than

<Register Automute_lev >

2096896/(<Register Automute_time > x (64 x fs))

where fs is the SPDIF sampling rate

DSD

Equal number of 1s and 0s in every 8

bits of data

2096896/(<Register Automute_time > x DATA_CLK)

Table5

De-emphasis

The de-emphasis feature is included for audio data that has utilized the 50/15µs pre-emphasis for noise reduction. There are

three de-emphasis filters, one for 32kHz, one for 44.1kHz, and one for 48kHz.

Volume Control

Each output channel has its own attenuation circuit. The attenuation for each channel is controlled independently. Each

channel can be attenuated from 0dB to

–127dB in 0.5dB steps.

Each 0.5dB step transition takes 64 intermediate levels. The result being that the level changes are done using small enough

steps so that no switching noise occurs during the transition of the volume control. When a new volume level is set, the

attenuation circuit will ramp softly to the new level.

Master Trim

Themaster trim sets the 0dB reference level for the volume control of each DAC. The master trim is programmable via

registers 24-27 and is a 32-bit signed number. Therefore it should never exceed 32'h7FFFFFFF (as this is full-scale signed).

PCM Audio Interface Formats

Several interface formats are provided so that direct connection to common audio processors is possible. The available

formats and their accompanying diagrams are listed in the following table. The audio interface format can be set by

programming the registers.

Format

Description

Figure

0

MSB First, Left Justified, up to 24-bit data

1A

1

I2S, up to 24-bit data

2A

2

MSB First, Right Justified, 24-bit data

3A

3

MSB First, Right Justified, 20-bit data

3B

4

MSB First, Right Justified, 16-bit data

3C

5

DSD Normal Mode

4A

6

DSD Phase Mode

4B

Table 6