CONFIDENTIAL ADVANCE INFORMATION Rev. 0.9 July 30, 2013
ES9018K2M Datasheet
ESS TECHNOLOGY, INC. 48401 Fremont Blvd., Fremont, CA 94538, USA Tel (510) 492-1088 • Fax (510) 492-1098
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FEATURE DESCRIPTION
Soft Mute
When Mute is asserted the output signal will ramp to the -∞ level. When Mute is reset the attenuation level will ramp back up
to the previous level set by the volume control register. Asserting Mute will not change the value of the volume control
register. The ramp rate is 0.0078125*FS/(2^(vol_rate-5)) dB/s, where FS = DATA_CLK/64 in PCM serial or DSD modes, or
SPDIF sampling rate in SPDIF mode.
Automute
During an automute condition the ramping of the volume of each DAC to -∞ can now be programmatically enabled or
disabled.
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>*DATA_CLK) Seconds.
o In SPDIF 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>*(64*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>*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 >*DATA_CLK)
SPDIF Data is continuously lower than
<Register Automute_lev >
2096896/(<Register Automute_time >*(64*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 >*DATA_CLK)
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 up to 128 intermediate levels, depending on the vol_rate register setting. 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
The master trim sets the 0dB reference level for the volume control of each DAC. The master trim is programmable via
registers 20-23 and is a 32bit signed number. Therefore it should never exceed 32'h7FFFFFFF (as this is full-scale signed).
All Mono Mode
An all mono mode where all DACs are driven from the same source is supported. This can be useful for high-end audio
applications. The source data for all DACs can be programmatically configured to be either CH1 or CH2.
De-emphasis
The de-emphasis feature is included for audio data that has utilized the 50/15uS pre-emphasis for noise reduction. There are
3 de-emphasis filters, one for 32 kHz, 44.1 kHz and 48 kHz.