User Manual

56 DS992F1
CS53L30
7.32 ADC2 Noise Gate Control
7.32 ADC2 Noise Gate Control
Address 0x30
R/W
76 5 43210
ADC2B_NG ADC2A_NG ADC2_NG_BOOST ADC2_NG_THRESH[2:0] ADC2_NG_DELAY[1:0]
Default00 0 00000
Bits Name Description
7,6 ADC2x_NG ADC2 noise-gate enable for Channels A and B. Enables independent noise gating for Channels A and B if ADC1_NG_
ALL = 0. This bit has no effect if ADC1_NG_ALL = 1
0 (Default) Disable noise gating on Channel x
1 Enable noise gating on Channel x. If a channel’s signal amplitude remains below the threshold setting (refer to ADC2_
NG_THRESH) for longer than the attack delay (debounce) time (refer to ADC2_NG_DELAY), noise gate muting is
applied to only that channel.
• Noise gate muting is removed (released) without debouncing when the signal level exceeds the threshold.
• Noise gate attack and release rates (soft-ramped as a function of Fs or abrupt) are set according to DIGSFT on p. 50.
5 ADC2_NG_
BOOST
ADC2 noise-gate threshold and boost for Channels A and B. These fields define the signal level where the noise gate begins
to engage. For low settings, the noise gate may not fully engage until the signal level is a few dB lower. Sets threshold level
(±2 dB) for Channel A and B noise gates. ADC2_NG_BOOST configures a +30-dB boost to the threshold setting.
4:2 ADC2_NG_
THRESH ADC2_NG_THRESH
000
001
010
011
100
101
110
111
Minimum Setting (ADC2_NG_BOOST = 0)
(Default) –64 dB
–66 dB
–70 dB
–73 dB
–76 dB
–82 dB
Reserved
Reserved
Minimum Setting (ADC2_NG_BOOST = 1)
–34 dB
–36 dB
–40 dB
–43 dB
–46 dB
–52 dB
–58 dB
–64 dB
1:0 ADC2_NG_
DELAY
Noise-gate delay timing for ADC2 Channels A and B. Sets the delay (debounce) time before the noise gate mute attacks.
00 (Default) 50 * (time base) ms
01 100 * (time base) ms
10 150 * (time base) ms
11 200 * (time base) ms
Time base = (6144 x [MCLK
INT
scaling factor])/MCLK
INT
.
MCLK
INT
scaling factor is 1, 2, or 4, depending on FS
INT
and the MCLK_INT_SCALE setting. Table 4-2 lists supported
configurations and their corresponding MCLK
INT
scaling factors. For MCLK
INT
= 6.144 MHz and MCLK_INT_SCALE = 0,
time base is 1 ms.
7.33 ADC2A/2B AFE Control
Address 0x31–0x32
R/W
76543210
ADC2A_PREAMP[1:0] ADC2A_PGA_VOL[5:0]
ADC2B_PREAMP[1:0] ADC2B_PGA_VOL[5:0]
Default00000000
Bits Name Description
7:6 ADC2x_
PREAMP
ADC2x mic preamp gain. Sets the gain of the mic preamp.
00 (Default) 0 dB (preamp bypassed)
01 +10 dB
10 +20 dB
11 Reserved
5:0 ADC2x_
PGA_
VOL
ADC2x PGA volume. Sets PGA attenuation/gain. Step size: ~0.5 dB.
01 1111–01 1000 12 dB…
00 0001 +0.5 dB
00 0000 (Default) 0 dB
11 1111 –0.5 dB
11 1010 –3.0 dB (Target setting for 600-mVrms analog-input amplitude)…
11 0100–10 0000 –6.0 dB
7.34 ADC2A/2B Digital Volume
Address 0x33–0x34
R/W
76543210
ADC2A_VOL[7:0]
ADC2B_VOL[7:0]
Default00000000
Bits Name Description
7:0 ADC2x_
VOL
ADC2x digital volume. Sets the ADC2x or DMIC signal volume based on the input source (see Table 4-5). Step size: 1.0 dB.
0111 1111–0000 1100 +12 dB
0000 1011 +11 dB …
0000 0000(Default) 0 dB
1111 1111 –1.0 dB
1111 1110 –2.0 dB…
1010 0000 –96.0 dB
1001 1111 –1000 0000 Mute