WM8945
Production Data
DESCRIPTION
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
12:8
DRC_KNEE2_OP
00000
Output signal at the Noise Gate
threshold ‘Knee2’.
00000 = -30dB
00001 = -31.5dB
00010 = -33dB
… (-1.5dB steps)
11110 = -75dB
11111 = -76.5dB
Only applicable when
DRC_KNEE2_OP_ENA = 1.
Output signal at the Compressor
‘Knee1’.
7:3
DRC_KNEE_OP
00000
00000 = 0dB
00001 = -0.75dB
00010 = -1.5dB
… (-0.75dB steps)
11110 = -22.5dB
11111 = Reserved
Compressor slope (upper region)
000 = 1 (no compression)
001 = 1/2
2:0
DRC_HI_COMP
011
010 = 1/4
011 = 1/8
100 = 1/16
101 = 0
110 = Reserved
111 = Reserved
Noise Gate slope
00 = 1 (no expansion)
01 = 2
R35 (23h)
9:8
7:5
DRC_NG_EXP
00
DRC Control 7
10 = 4
11 = 8
Compressor slope (lower region)
000 = 1 (no compression)
001 = 1/2
DRC_LO_COMP
000
010 = 1/4
011 = 1/8
100 = 0
101 = Reserved
11X = Reserved
Table 17 DRC Control Registers
GAIN LIMITS
The minimum and maximum gain applied by the DRC is set by register fields DRC_MINGAIN,
DRC_MAXGAIN and DRC_NG_MINGAIN. These limits can be used to alter the DRC response from
that illustrated in Figure 17. If the range between maximum and minimum gain is reduced, then the
extent of the dynamic range control is reduced.
The minimum gain in the Compression regions of the DRC response is set by DRC_MINGAIN. The
minimum gain in the Noise Gate region is set by DRC_NG_MINGAIN. The minimum gain limit
prevents excessive attenuation of the signal path.
The maximum gain limit set by DRC_MAXGAIN prevents quiet signals (or silence) from being
excessively amplified.
PD, May 2011, Rev 4.1
40
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
