WM8985_07 WOLFSON [Wolfson Microelectronics plc], WM8985_07 Datasheet - Page 100

• Manufacturer Part Number: WM8985_07
• Description: Multimedia CODEC With Class D Headphone and Line Out
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

WM8985
w
32 (20h)
33 (21h)
34 (22h)
REGISTER
ADDRESS
8:7
6
5:3
2:0
7:4
3:0
8
7:4
BIT
ALCSEL
ALCMAXGAIN
ALCMINGAIN
ALCHLD
ALCLVL
ALCMODE
ALCDCY
[3:0]
LABEL
00
0
111
000
0000
1011
0
0011
0011
DEFAULT
ALC function select:
00=ALC off
01=ALC right only
10=ALC left only
11=ALC both on
Reserved. Initialise to 0
Set Maximum Gain of PGA
111=+35.25dB
110=+29.25dB
101=+23.25dB
100=+17.25dB
011=+11.25dB
010=+5.25dB
001=-0.75dB
000=-6.75dB
Set minimum gain of PGA
000=-12dB
001=-6dB
010=0dB
011=+6dB
100=+12dB
101=+18dB
110=+24dB
111=+30dB
ALC hold time before gain is increased.
0000 = 0ms
0001 = 2.67ms
0010 = 5.33ms
… (time doubles with every step)
1111 = 43.691s
ALC target – sets signal level at ADC input
1111 : -1.5dBFS
1110 : -1.5dBFS
1101 : -3dBFS
1100 : -4.5dBFS
...... (-1.5dB steps)
0001 : -21dBFS
0000 : -22.5dBFS
Determines the ALC mode of operation:
0=ALC mode
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)
Per step
410us
820us
1.64ms
420ms
DESCRIPTION
Per 6dB
3.3ms
6.6ms
13.1ms
3.36s
90% of range
24ms
48ms
192ms
24.576s
PP, Rev 3.5, March 2007
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Pre-Production
REFER TO
100