AK2308LV_05 Datasheet, PDF (17/31 Pages) Asahi Kasei Microsystems – SPEECH CODEC for Digital Key telephone

ASAHI KASEI
[AK2308LV]
3-2-2. TX voice path gain controls
TX side voice path has two gain control blocks. One is a analog volume and the other is a digital attenuator after D/A
converter. These voice path gains are controlled through the following register.
TX Voice Path Gain Control (TX digital Attenuator, VOL 1)
Register Type : Read Write[Address:0010 D5-D0: (TX_pad, VTX4-VTX0)]
ADD
D7
D6
D5
D4
D3
D2
D1
3
-
-
Tx_pad VTX4 VTX3 VTX2 VTX1
default 0
0
1
0
0
0
0
D0
VTX0
0
VTX[4-0]; The digital attenuator for TX side voice path. The gain variation is from +15dB to –16dB by 1dB step.
VTX4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
VTX3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
VTX2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
VTX1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
VTX0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
TX digital Attenuator
-16dB
-15dB
-14dB
-13dB
-12dB
-11dB
-10dB
-9dB
-8dB
-7dB
-6dB
-5dB
-4dB
-3dB
-2dB
-1dB
0dB
+1dB
+2dB
+3dB
+4dB
+5dB
+6dB
+7dB
+8dB
+9dB
+10dB
+11dB
+12dB
+13dB
+14dB
+15dB
Comment
default
TX_pad: The digital attenuator for TX side voice path. The gain variation is 0dB or –14dB
TX_pad
0
1
TX digital pad
0dB
-14dB
Comment
default
MS0227-E-01
17
2005/12