R01UH0823EJ0100 Rev.1.00
Page 1635 of 1823
Jul 31, 2019
RX23W Group
47. Comparator B (CMPBa)
47.
Comparator B (CMPBa)
Comparator B compares a reference input voltage and an analog input voltage. comparator B2 and comparator B3
operate independently.
In this section, “PCLK” is used to refer to PCLKB.
47.1
Overview
The comparison result of the reference input voltage and analog input voltage can be read by software. The comparison
result can also be output externally. The reference input voltage can be selected from either an input to the CVREFBn pin
(n = 2, 3)
or the internal reference voltage generated internally in the MCU.
The comparator B response speed can be set before starting an operation. Setting high-speed mode decreases the
response delay time, but increases current consumption. Setting low-speed mode increases the response delay time, but
decreases current consumption.
lists the specifications of comparator B,
shows a block diagram of comparators B2 and B3
when the window function is disabled, and
shows a block diagram of comparators B2 and B3 when the
window function is enabled.
lists the I/O pins of comparator B.
Note 1. VRFL: low-side reference voltage, VRFH: high-side reference voltage
Table 47.1
Comparator B Specifications (n = 2, 3)
Item
Specification
Analog input voltage
Input voltage to the CMPBn pin
Reference input voltage
Input voltage to the CVREFBn pin or internal reference voltage
Comparison result
Read from the CPBFLG.CPBnOUT flag
The comparison result can be output to the CMPOBn pin.
Interrupt request generation timing
When comparator B2 comparison result changes
When comparator B3 comparison result changes
Selectable function
Digital filter function
Whether the digital filter is applied or not, and the sampling frequency can be selected.
Window function
Whether the window function is enabled or disabled (VRFL < CMPBn < VRFH)*
selected.
Reference input voltage
CVREFBn pin input or internal reference voltage (generated internally) can be selected.
Comparator B response speed
High-speed mode/low-speed mode can be selected.
Low power consumption function
Module stop state can be set.