r5f21346mnfp Renesas Electronics Corporation., r5f21346mnfp Datasheet - Page 70

• Manufacturer Part Number: r5f21346mnfp
• Description: Single-chip Mcus Incorporates The R8c Cpu Core
• Manufacturer: Renesas Electronics Corporation.

R8C/34M Group
R01UH0131EJ0100 Rev.1.00
Jun 21, 2011
6.
The voltage detection circuit monitors the voltage input to the VCC pin. This circuit can be used to monitor the VCC
input voltage by a program.
6.1
Table 6.1
VCC
monitor
Process at
voltage
detection
Digital filter
The detection voltage of voltage detection 0 can be selected among four levels using the OFS register.
The detection voltage of voltage detection 1 can be selected among 16 levels using the VD1LS register.
As a detection target, the voltage input to VCC and the LVCMP2 pin can be switched for voltage detection 2 only.
The voltage monitor 0 reset, and voltage monitor 1 interrupt and voltage monitor 2 interrupt can also be used.
Note that voltage monitor 1 and voltage monitor 2 share the voltage detection circuit with comparator A1 and
comparator A2. Either voltage monitor 1 and voltage monitor 2 or comparator A1 and comparator A2 can be
selected.
Voltage Detection Circuit
Overview
Item
Voltage to
monitor
Detection
target
Detection
voltage
Monitor
Reset
Interrupts
Switching
enable/disable
Sampling
time
Voltage Detection Circuit Specifications
Vdet0
Whether passing through
Vdet0 by rising or falling
Selectable among
4 levels using the OFS
register.
None
Voltage monitor 0 reset
Reset at Vdet0 > VCC;
CPU operation restarts
at VCC > Vdet0
None
No digital filter function
—
Voltage Monitor 0
Supported
Vdet1
Whether passing through
Vdet1 by rising or falling
Selectable among 16 levels
using the VD1LS register.
The VW1C3 bit in
the VW1C register
Whether VCC is higher or
lower than Vdet1
None
Voltage monitor 1 interrupt
Non-maskable or maskable
selectable
Interrupt request at:
Vdet1 > VCC
and/or
VCC > Vdet1
(fOCO-S divided by n) × 2
n: 1, 2, 4, and 8
Voltage Monitor 1
Vdet2
Whether passing through
Vdet2 by rising or falling
The input voltage to VCC
and the LVCMP2 pin can be
switched by the VCA24 bit in
the VCA2 register.
The detection voltage level
varies depending on when
VCC is selected or when
LVCMP2 is selected.
Each value is set as the
fixed level.
The VCA13 bit in
the VCA1 register
Whether VCC is higher or
lower than Vdet2
None
Voltage monitor 2 interrupt
selectable
Interrupt request at:
Vdet2 > VCC (LVCMP2)
and/or
VCC (LVCMP2) > Vdet2
Supported
(fOCO-S divided by n) × 2
n: 1, 2, 4, and 8
Non-maskable or maskable
6. Voltage Detection Circuit
Voltage Monitor 2
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