Pre-Production
WM8985
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
0000 = -22.5dBFS
7:4
ALCHLD
0000
ALC hold time before gain is
increased.
[3:0]
(0ms)
0000 = 0ms
0001 = 2.67ms
0010 = 5.33ms
0011 = 10.66ms
0100 = 21.32ms
0101 = 42.64ms
0110 = 85.28ms
0111 = 0.17s
1000 = 0.34s
1001 = 0.68s
1010 or higher = 1.36s
R34 (22h)
8
ALCMODE
0
Determines the ALC mode of
operation:
ALC Control
3
0 = ALC mode (Normal Operation)
1 = Limiter mode.
7:4
ALCDCY
[3:0]
0011
Decay (gain ramp-up) time
(ALCMODE ==0)
(13ms/6dB)
Per
step
Per
6dB
90% of
range
0000
0001
0010
410us
820us
1.64ms
3.3ms
6.6ms
13.1ms
24ms
48ms
192ms
… (time doubles with every step)
1010
or
420ms
3.36s
24.576s
higher
0011
Decay (gain ramp-up) time
(ALCMODE ==1)
(2.9ms/6dB)
Per
step
Per
6dB
90% of
range
0000
0001
90.8us
726.4us 5.26ms
181.6us 1.453ms 10.53
ms
0010
363.2us 2.905ms 21.06
ms
… (time doubles with every step)
1010 93ms 744ms 5.39s
3:0
ALCATK
[3:0]
0010
ALC attack (gain ramp-down) time
(ALCMODE == 0)
(832us/6dB)
Per
step
Per
6dB
90% of
range
0000
0001
0010
104us
208us
416us
832us
1.66ms
3.32ms
6ms
12ms
24.1ms
… (time doubles with every step)
1010
or
106ms
852ms
6.18s
higher
0010
ALC attack (gain ramp-down) time
(ALCMODE == 1)
(182us/6dB)
Per
step
Per
6dB
90% of
range
0000
22.7us
182.4us 1.31ms
PP, Rev 3.4, October 2006
w
43
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
