Rainbow Electronics MAX98088 - Manual (Page 71)

Stereo Audio Codec
with FLEXSOUND Technology
MAX98088
71
Table 6. Record Path Signal Processing Registers (continued)
REGISTER BIT NAME DESCRIPTION
0x3F
3
AGCATK
AGC Attack Time
Defined as the time required to reduce gain by 63% of the total gain reduction (one time
constant of the exponential response). Attack times are longer for low AGC threshold
levels. See Figure 12 for details.
00 = 2ms
01 = 7.2ms
10 = 31ms
11 = 123ms
2
1
AGCHLD
AGC Hold Time
The delay before the AGC release begins. The hold time counter starts whenever the
signal drops below the AGC threshold and is reset by any signal that exceeds the
threshold. Set AGCHLD to enable the AGC circuit. See Figure 12 for details.
00 = AGC disabled
01 = 50ms
10 = 100ms
11 = 400ms
0
0x40
7
ANTH
Noise Gate Threshold
Gain is reduced for signals below the threshold to quiet noise. The thresholds are relative
to the ADC’s full-scale output voltage.
6
VALUE
THRESHOLD
(dBFS)
VALUE
THRESHOLD
(dBFS)
0x0 Noise gate disabled 0x8 -45
0x1 Reserved 0x9 -41
5
0x2 Reserved 0xA -38
0x3 -64 0xB -34
0x4 -62 0xC -30
4
0x5 -58 0xD -27
0x6 -53 0xE -22
0x7 -50 0xF -16
3
AGCTH
AGC Threshold
Gain is reduced when signals exceed the threshold to prevent clipping. The thresholds
are relative to the ADC’s full-scale voltage.
2
VALUE
THRESHOLD
(dBFS)
VALUE
THRESHOLD
(dBFS)
0x0 -3 0x8 -11
0x1 -4 0x9 -12
1
0x2 -5 0xA -13
0x3 -6 0xB -14
0x4 -7 0xC -15
0
0x5 -8 0xD -16
0x6 -9 0xE -17
0x7 -10 0xF -18