Voltage Detection Circuit - Renesas R8C Series User Manual

R8C/1A Group, R8C/1B Group
7.

Voltage Detection Circuit

The voltage detection circuit monitors the input voltage to the VCC pin. This circuit can be used to monitor the VCC
input voltage by a program. Alternately, voltage monitor 1 reset, voltage monitor 2 interrupt, and voltage monitor 2
reset can also be used.
Table 7.1 lists the Specifications of Voltage Detection Circuit and Figures 7.1 to 7.3 show the Block Diagrams. Figures
7.4 to 7.6 show the Associated Registers.
Table 7.1 Specifications of Voltage Detection Circuit
VCC monitor
Process when voltage is
detected
Digital filter
Rev.1.30 Dec 08, 2006
REJ09B0252-0130
Item
Voltage to monitor
Detection target
Monitor
Reset
Interrupt
Switch
enabled/disabled
Sampling time
Page 44 of 315
Voltage Detection 1
Vdet1
Passing through Vdet1
by rising or falling
None
Voltage monitor 1 reset
Reset at Vdet1 > VCC;
restart CPU operation at
VCC > Vdet1
None
Available
(Divide-by-n of fRING-S)
x 4
n: 1, 2, 4, and 8
7. Voltage Detection Circuit
Voltage Detection 2
Vdet2
Passing through Vdet2
by rising or falling
VCA13 bit in VCA1
register
Whether VCC is higher
or lower than Vdet2
Voltage monitor 2 reset
Reset at Vdet2 > VCC;
restart CPU operation
after a specified time
Voltage monitor 2
interrupt
Interrupt request at
Vdet2 > VCC and VCC >
Vdet2 when digital filter
is enabled;
interrupt request at
Vdet2 > VCC or VCC >
Vdet2 when digital filter
is disabled
Available
(Divide-by-n of fRING-S)
x 4
n: 1, 2, 4, and 8