WM8976
Pre-Production
REGISTER
ADDRESS
BIT
LABEL
ALCZC
DEFAULT
DESCRIPTION
8
0 (zero
cross off)
ALC uses zero cross detection circuit.
0 = Disabled (recommended)
1 = Enabled
7:4
ALCHLD
[3:0]
0000
ALC hold time before gain is
increased.
(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)
(26ms/6dB)
Per
step
Per
6dB
90% of
range
0000
0001
0010
410us
820us
1.64ms
3.38ms
6.56ms
13.1ms
23.6ms
47.2ms
94.5ms
… (time doubles with every step)
1010
or
420ms
3.36s
24.2s
higher
0011
Decay (gain ramp-up) time
(ALCMODE ==1)
(5.8ms/6dB)
Per
step
Per
6dB
90% of
range
0000
0001
0010
90.8us
182us
363us
726us
5.23ms
10.5ms
20.9ms
1.45ms
2.91ms
… (time doubles with every step)
1010 93ms 744ms 5.36s
3:0
ALCATK
[3:0]
0010
ALC attack (gain ramp-down) time
(ALCMODE == 0)
(3.3ms/6dB)
Per
step
Per
6dB
90% of
range
0000
0001
0010
104us
208us
416us
832us
1.66ms
3.33ms
6ms
12ms
24ms
… (time doubles with every step)
1010
or
106ms
852ms
6.13s
higher
0010
ALC attack (gain ramp-down) time
(ALCMODE == 1)
(726us/6dB)
Per
step
Per
6dB
90% of
range
PP Rev 3.0 April 2006
30
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
