WM8976 Wolfson Microelectronics Ltd., WM8976 Datasheet - Page 30

• Manufacturer Part Number: WM8976
• Description: The WM8976 is a low power, high quality stereo codec designed for portable applications such as Digital still camera or Digital Camcorde
• Manufacturer: Wolfson Microelectronics Ltd.

WM8976
w
R34 (22h)
ALC Control
3
REGISTER
ADDRESS
8
7:4
8
7:4
3:0
BIT
ALCZC
ALCHLD
[3:0]
ALCMODE
ALCDCY
[3:0]
ALCATK
[3:0]
LABEL
0 (zero
cross off)
0000
(0ms)
0
0011
(26ms/6dB)
0011
(5.8ms/6dB)
0010
(3.3ms/6dB)
0010
(726us/6dB)
DEFAULT
ALC uses zero cross detection circuit.
0 = Disabled (recommended)
1 = Enabled
ALC hold time before gain is
increased.
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
Determines the ALC mode of
operation:
0 = ALC mode (Normal Operation)
1 = Limiter mode.
Decay (gain ramp-up) time
(ALCMODE ==0)
0000
0001
0010
… (time doubles with every step)
1010
or
higher
Decay (gain ramp-up) time
(ALCMODE ==1)
0000
0001
0010
… (time doubles with every step)
1010
ALC attack (gain ramp-down) time
(ALCMODE == 0)
0000
0001
0010
… (time doubles with every step)
1010
or
higher
ALC attack (gain ramp-down) time
(ALCMODE == 1)
Per
step
410us
820us
1.64ms
420ms
Per
step
90.8us
182us
363us
93ms
Per
step
104us
208us
416us
106ms
Per
step
DESCRIPTION
PP Rev 3.0 April 2006
Per
6dB
3.38ms
6.56ms
13.1ms
3.36s
Per
6dB
726us
1.45ms
2.91ms
744ms
Per
6dB
832us
1.66ms
3.33ms
852ms
Per
6dB
Pre-Production
90% of
range
23.6ms
47.2ms
94.5ms
24.2s
90% of
range
5.23ms
10.5ms
20.9ms
90% of
range
24ms
90% of
range
5.36s
6ms
12ms
6.13s
30