ISD91200 Series Technical Reference Manual
Release Date: Sep 16, 2019
- 352 -
Revision 2.4
5.16 Volume Control
5.16.1 Overview and feature
The volume control function is digital domain gain control and supports both side of SDADC and
DPWM. The audio signal can be changed from 36 dB to -108dB if using this feature.
The volume control is enabled by setting
SDADCVOLEN
and DPWMVOL_EN. The volume control shares
a clock source with the BIQ filter so CLK_APBCLK0.BIQALCEN, also the volume value will multiply
BIQ result so BIQ_
DLCOEFF
must be set to operate volume control.
5.16.2 Volume Control Register Map
R: read only, W: write only, R/W: both read and write
Register
Offset
R/W Description
Reset Value
VOLCTRL Base Address:
VOLCTRL_BA = 0x400B_00a0
VOLCTRL_EN
VOL0x00
R/W Volume Control Enable Register
0x0000_0000
VOLCTRL_ADCVAL
VOL0x04
R/W ADC Volume Control Value
0x0004_0000
VOLCTRL_DPWMVAL
VOL0x08
R/W DPWM Volume Control Value
0x0004_0000