alc882 Realtek Semiconductor Corporation, alc882 Datasheet - Page 80

• Manufacturer Part Number: alc882
• Description: 7.1+2 Channel High Definition Audio Codec
• Manufacturer: Realtek Semiconductor Corporation

10.2. Volume Control by External Variable Resistor
The input range of DCVOL is from GND to AVDD. A 5-bit resolution ADC is used to convert the DC
level on a variable resistor into 32 steps for Volume knob use. DC level changes are reflected to software
to control the master volume.
10.3. Volume Control by GPIO0/GPIO1
Detect Low pulses generated at GPIO0 and GPIO1 calculate the Up and Down count into 7 bits of
volume step. ‘Mute’ is also sampled to toggle the mute status. Hardware does not adjust volume. The
count value is reported via unsolicited response to software to control the master volume.
7.1+2 Channel High Definition Audio Codec
Variable
Resistor
Figure 21. Volume Control by External Variable Resistor
AVDD=5V
Figure 22. Volume Control by GPIO0 and GPIO1
DCVOL (Pin 33)
ALC882
70
+5V: DCVOL=31
0V: DCVOL=0
ADC
5-bit
Volume Code [4:0]
Track ID: JATR-1076-21
ALC882 Series
Datasheet
Rev. 1.5