Renesas RL78/G1P Hardware User Manual page 660

RL78/G1P
19.5 Cautions for Voltage Detector
(1) Voltage fluctuation when power is supplied
In a system where the supply voltage (V
the system may be repeatedly reset and released from the reset status. In this case, the time from release of reset to
the start of the operation of the microcontroller can be arbitrarily set by taking the following action.
<Action>
After releasing the reset signal, wait for the supply voltage fluctuation period of each system by means of a software
counter that uses a timer, and then initialize the ports.
Figure 19-9. Example of Software Processing If Supply Voltage Fluctuation is 50
Initialization processing <1>
Note
No
Initialization processing <2>
Note If reset is generated again during this period, initialization processing <2> is not started.
Remark m = 0
n = 0 to 3
R01UH0895EJ0100 Rev.1.00
Nov 29, 2019
) fluctuates for a certain period in the vicinity of the LVD detection voltage,
DD
Detection Voltage
Reset
Setting timer array unit
(to measure 50 ms)
Clearing WDT
50 ms have passed?
(TMIFmn = 1?)
Yes
CHAPTER 19 VOLTAGE DETECTOR
Refer to Figure 17-5 Procedure for Checking Reset Source.
; e.g. f = High-speed on-chip oscillator clock (4.04 MHz (MAX.))
CLK
Source: f = (4.04 MHz (MAX.))/2
MCK
where comparison value = 789: ≈ 50 ms
Timer starts (TSmn = 1).
;
Initial setting for port.
Setting of division ratio of system clock,
such as setting of timer or A/D converter.

s or Less in Vicinity of LVD
8
,
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