
R8C/14 Group, R8C/15 Group 6. Voltage Detection Circuit
Rev.2.10 Jan 19, 2006 Page 32 of 253
REJ09B0164-0210
6.2 Voltage Monitor 1 Reset
Table 6.2 lists the Setting Procedure of Voltage Monitor 1 Reset Associated Bit and Figure 6.7 shows
the Operating Example of Voltage Monitor 1 Reset. When using the voltage monitor 1 reset to exit stop
mode, set the VW1C1 bit in the VW1C register to “1” (digital filter disabled).
NOTES:
1. When the VW1C0 bit is set to “0” (disabled), procedures 3, 4 and 5 can be executed simultaneously
(with 1 instruction).
Figure 6.7 Operating Example of Voltage Monitor 1 Reset
Table 6.2 Setting Procedure of Voltage Monitor 1 Reset Associated Bit
Procedure When Using Digital Filter When Not Using Digital Filter
1 Set the VCA26 bit in the VCA2 register to “1” (voltage detection 1 circuit enabled)
2 Wait for td(E-A)
3
(1)
Select the sampling clock of the digital filter
by the VW1F0 to VW1F1 bits in the VW1C
register
Set the VW1C7 bit in the VW1C register to
“1”
4
(1)
Set the VW1C1 bit in the VW1C register to
“0” (digital f ilter enabled).
Set the VW1C1 bit in the VW1C register to
“1” (digital filter disabled)
5
(1)
Set the VW1C6 bit in the VW1C register to “1” (voltage monitor 1 reset mode)
6 Set the VW1C2 bit in the VW1C register to “0”
7 Set the CM14 bit in the CM1 register to “0”
(low-speed on-chip oscillator on)
−
8 Wait for the sampling clock of the digital
filter x 4 cycles
− (no wait time)
9 Set the VW1C0 bit in the VW1C register to “1” (enables voltage monitor 1 reset)
Vdet1
(Typ. 2.85V)
Internal Reset Signal
VCC
The above applies to the following conditions.
• VCA26 bit in VCA2 register = 1 (voltage detection 1 circuit enabled)
• VW1C0 bit in VW1C register = 1 (enables voltage monitor 1 reset )
• VW1C6 bit in VW1C register = 1 (voltage monitor 1 reset mode)
When the internal reset signal is held “L”, the pins, CPU and SFR are reset.
The internal reset signal is changed from “L” to “H”, the program is executed beginning with the address indicated by the
reset vector.
Refer to
4. Special Function Register (SFR) for the SFR status after reset.
1
fRING-S
x 32
Sampling Clock of
Digital Filter x 4 Cycles
When the VW1C1 bit is set
to “0” (digital filter enabled)
Internal Reset Signal
When the VW1C1 bit is set
to “1” (digital filter disabled)
and the VW1C7 bit is set
to “1”
1
fRING-S
x 32
VW1C1 and VW1C7 : Bits in VW1C Register
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