Cirrus Logic CS42L55 - Manual (Page 64)

64 DS773F1
CS42L55
6.31 ALC Threshold (Address 26h)
6.31.1 ALC Maximum Threshold
Sets the maximum level, below full-scale, at which to limit and attenuate the input signal at the attack rate
(ALCARATE -
“ALC Attack Rate” on page 63 ).
6.31.2 ALC Minimum Threshold
Sets the minimum level at which to disengage the ALC’s attenuation or amplify the input signal at the re-
lease rate (ALCRRATE -
“ALC Release Rate” on page 63 ) until levels lie between the ALCMAX and AL-
CMIN thresholds.
Note: This setting is usually set slightly below the ALCMAX threshold.
6.32 Noise Gate Control (Address 27h)
6.32.1 Noise Gate All Channels
Sets which channels are attenuated when clipping on any single channel occurs.
7 6 5 4 3 2 1 0
ALCMAX2 ALCMAX1 ALCMAX0 ALCMIN2 ALCMIN1 ALCMIN0 Reserved Reserved
MAX[2:0] Threshold Setting
000 0 dB
001 -3 dB
010 -6 dB
011 -9 dB
100 -12 dB
101 -18 dB
110 -24 dB
111 -30 dB
Application: “Automatic Level Control (ALC)” on page 24
ALCMIN[2:0] Threshold Setting
000 0 dB
001 -3 dB
010 -6 dB
011 -9 dB
100 -12 dB
101 -18 dB
110 -24 dB
111 -30 dB
Application: “Automatic Level Control (ALC)” on page 24
7 6 5 4 3 2 1 0
NGALL NG NG_BOOST THRESH2 THRESH1 THRESH0 NGDELAY1 NGDELAY0
NGALL Noise Gate triggered by:
0
Individual channel; Any channel that falls below the threshold setting triggers the noise gate attenuation for
ONLY that channel.
1
Both channels A & B; Both channels must fall below the threshold setting for the noise gate attenuation to
take effect.