alc203-lf Realtek Semiconductor Corporation, alc203-lf Datasheet - Page 45

• Manufacturer Part Number: alc203-lf
• Description: Two-channel Ac?97 2.3 Audio Codec
• Manufacturer: Realtek Semiconductor Corporation

9.11 GPIO Smart Volume Control
A 5-bit volume code is controlled by GPIO0 (volume up) and GPIO1 (volume down) when Smart GPIO Volume Control is
selected. The single step and consecutive step (0.11Sec/step) of volume control (up, down and mute) can be implemented by
GPIO0 and GPIO1.
Two-Channel AC’97 2.3 Audio Codec
4.7K
Vol Mute
External Circuitry
+3.3VCC
4.7K
Vol Down
Vol Up
GPIO1
GPIO0
External Circuits for Volume Up/Down/Mute
+3.3VCC
+3.3VCC
ALC203
50K
50K
3
3
Vth=2/3 VCC
Vth=1/3 VCC
41
2
2
A
B
GPIO1
+3.3V
1.65V
0V
A
1
0
0
B
1
1
0
Signal
Vol Down
Vol Down
Mute
ALC203 DataSheet
Vol Down
Mute
Vol Up
Rev1.6