Functional Descriptions; Comparator Inputs And Output; Comparator Reference Voltage; Figure 35. 6-Bit Scaler For Comparator Voltage Reference Block Diagram - Holtek HT32F12345 User Manual

32-Bit Arm ® Cortex ® -M3 MCU
HT32F12345

Functional Descriptions

Comparator Inputs and Output

The I/O pins used as comparator inputs or output must be configured in the AFIO controller
registers. The detail comparator I/Os information will be referred in pin assignment table in
the datasheet. The output can also be internally connected to a variety of timer or ADC for
trigger purpose. The comparator output can be used for both internal and external functions
simultaneously.

Comparator Reference Voltage

The comparator reference voltage is a 64-tap resistor ladder network that provides a selectable
reference voltage. It also has a power-down function to conserve power when the reference is not
used. The comparator voltage reference provides 64 distinct levels. The equation used to calculate
the comparator reference voltage is as follows:
CVREF = CVRVAL × (V
The comparator voltage reference source voltage can come from either V
pin. The voltage source is selected by the CVRSS bit in the Comparator Control Register CMPCR.
The primary purpose of the CVREF output is to provide a reference voltage for the analog
comparator; it may also be used independently of them and configured output to CN pin by setting
the CVROE bit in the Comparator Control Register CMPCR. The settling time of the comparator
voltage reference must be considered when changing the CVREF output.
V
DDA
V
REF+
CVREN

Figure 35. 6-Bit Scaler for Comparator Voltage Reference Block Diagram

Rev. 1.10
– V ) / 63, If the CVR reference voltage source is selected the V
DDA SSA
CVRSS = 0
CVRSS = 1
R
R
R
R
R
R
R
6-Bit Scaler for Comparator
Voltage Reference
216 of 590
or the external V
DDA
CVRVAL[5:0]
CVREF
November 28, 2018
.
DDA
REF+