ISD91200 Series Technical Reference Manual
Release Date: Sep 16, 2019
- 408 -
Revision 2.4
7.4
Analog Functional Blocks
7.4.1
Overview
The ISD91200 contains a variety of analog functional blocks that facilitate audio processing, enable
analog GPIO functions (current source, relaxation oscillator, and comparator), adjust and measure
internal oscillator and provide voltage regulation. These blocks are controlled by registers in the analog
block address space. This section describes these functions and registers.
7.4.2
Features
VMID reference voltage generation.
Current source generation for AGPIO (Analog enabled GPIO).
LDO control for GPIOA[7:0] power domain and external device use.
Operational Amplifier
Comparator
Microphone Bias generator.
Analog Multiplexer.
Programmable Gain Amplifier (PGA) for Audio Path
HIRC Frequency Control.
CapSense Relaxation Oscillator.
Oscillator Frequency Measurement block.
7.4.3
Register Map
R
: read only,
W
: write only,
R/W
: read/write
Register
Offset
R/W
Description
Reset Value
ANA Base Address:
ANA_BA = 0x4008_0000
ANA_VMID
0x00
R/W
VMID Reference Control Register
0x0000_0007
ANA_LDOSEL
0x20
R/W
LDO Voltage Select Register
0x0000_0000
ANA_LDOPD
0x24
R/W
LDO Power Down Register
0x0000_0001
ANA_MICBSEL
0x28
R/W
Microphone Bias Voltage Level Selection
0x0000_0000
ANA_MICBEN
0x2C
R/W
Microphone Bias Enable
0x0000_0001
ANA_TRIM
0x84
R/W
Oscillator Trim Register
0x0000_XXXX
ANA_FQMMCTL
0x94
R/W
Frequency Measurement Control Register
0x0000_0001
ANA_FQMMCNT
0x98
R
Frequency Measurement Count Register
0x0000_0000
ANA_FQMMCYC
0x9C
R/W
Frequency Measurement Cycle Register
0x0000_0000