Cirrus Logic CS42L51 - Manual (Page 72)

72 DS679F1
CS42L51
Function:
Sets the minimum level at which to disengage the ALC’s attenuation or amplify the input signal at a rate set
in the release rate register until levels again reach this minimum threshold. The ALC uses this minimum as
a hysteresis point for the input signal as it maintains the signal below the maximum as well as below the
minimum setting. This provides a more natural sound as the ALC attacks and releases.
6.26 Noise Gate Configuration & Misc. (Address 1Fh)
Noise Gate Channel Gang (NG_ALL)
Default: 0
0 - Disabled
1 - Enabled
Function:
Gangs the noise gate function for channel A and B. When enabled, both channels must fall below the thresh-
old setting for the noise gate attenuation to take effect.
Noise Gate Enable (NG_EN)
Default: 0
0 - Disabled
1 - Enabled
Function:
Enables the noise gate. Maximum attenuation is relative to all gain settings applied.
Noise Gate Boost (NG_BOOST) and Threshold (THRESH[3:0])
Default: 000
011 -9
100 -12
101 -18
110 -24
111 -30
7 6 5 4 3 2 1 0
NG_ALL NG_EN NG_BOOST THRESH2 THRESH1 THRESH0 NGDELAY1 NGDELAY0
THRESH[2:0]
Minimum Setting
(NG_BOOST = ‘0’b)
Minimum Setting
(NG_BOOST = ‘1’b)
000 -64 dB -34 dB
001 -67 dB -37 dB
010 -70 dB -40 dB
011 -73 dB -43 dB
100 -76 dB -46 dB
101 -82 dB -52 dB
110 Reserved -58 dB
111 Reserved -64 dB
MIN[2:0]
Threshold
Setting
(dB)