R8C/1A Group, R8C/1B Group
7. Voltage Detection Circuit
Rev.1.30
Dec 08, 2006
Page 53 of 315
REJ09B0252-0130
7.3
Voltage Monitor 2 Interrupt and Voltage Monitor 2 Reset
Table 7.3 lists the Setting Procedure of Voltage Monitor 2 Interrupt and Voltage Monitor 2 Reset Associated Bits.
Figure 7.9 shows an Operating Example of Voltage Monitor 2 Interrupt and Voltage Monitor 2 Reset. To use
voltage monitor 2 interrupt or voltage monitor 2 reset to exit stop mode, set the VW2C1 bit in the VW2C register to
1 (digital filter disabled).
NOTES:
1. Set the VW2C7 bit to 1 (when VCC reaches Vdet2 or below) for the voltage monitor 2 reset.
2. When the VW2C0 bit is set to 0 (disabled), steps 3, 4 and 5 can be executed simultaneously (with 1
instruction).
Table 7.3
Setting Procedure of Voltage Monitor 2 Interrupt and Voltage Monitor 2 Reset
Associated Bits
Step
When Using Digital Filter
When Not Using Digital Filter
Voltage Monitor 2
Interrupt
Voltage Monitor 2
Reset
Voltage Monitor 2
Interrupt
Voltage Monitor 2
Reset
1
Set the VCA27 bit in the VCA2 register to 1 (voltage detection 2 circuit enabled).
2
Wait for td(E-A)
3
(2)
Select the sampling clock of the digital filter
by bits VW2F0 to VW2F1 in the VW2C
register.
Select the timing of the interrupt and reset
request by the VW2C7 bit in the VW2C
register
(1)
.
4
(2)
Set the VW2C1 bit in the VW2C register to 0
(digital filter enabled).
Set the VW2C1 bit in the VW2C register to 1
(digital filter disabled).
5
(2)
Set the VW2C6 bit in
the VW2C register to
0 (voltage monitor 2
interrupt mode).
Set the VW2C6 bit in
the VW2C register to
1 (voltage monitor 2
reset mode).
Set the VW2C6 bit in
the VW2C register to
0 (voltage monitor 2
interrupt mode).
Set the VW2C6 bit in
the VW2C register to
1 (voltage monitor 2
reset mode).
6
Set the VW2C2 bit in the VW2C register to 0 (passing of Vdet2 is not detected).
7
Set the CM14 bit in the CM1 register to 0
(low-speed on-chip oscillator on).
−
8
Wait for 4 cycles of the sampling clock of the
digital filter
−
(No wait time)
9
Set the VW2C0 bit in the VW2C register to 1 (voltage monitor 2 interrupt/reset enabled).
