Resets; Introduction - Renesas M16C/64A Series User Manual

M16C/64A Group
6.

Resets

6.1

Introduction

The following resets can be used to reset the MCU: hardware reset, power-on reset, voltage monitor 0
reset, voltage monitor 1 reset, voltage monitor 2 reset, oscillator stop detect reset, watchdog timer reset,
and software reset.
Table 6.1 lists the Types of Resets and Figure 6.1 shows the Reset Circuit Block Diagram. Symbols (A) to
(D) in the table and figure is explained in Table 6.2. Table 6.3 lists the I/O Pins.
Table 6.1 Types of Resets
Reset Name
Hardware reset
Power-on reset
Voltage monitor 0 reset
Voltage monitor 1 reset
Voltage monitor 2 reset
Oscillator stop detect reset
Watchdog timer reset
Software reset
RESET
Power-on reset
VCC1
Voltage detector
Watchdog timer
Oscillator stop/
XIN
restart detector
Figure 6.1 Reset Circuit Block Diagram
R01UH0136EJ0210 Rev.2.10
Jul 31, 2012
A low-level signal is applied to the RESET pin.
A rise in voltage on VCC1
A drop in voltage on VCC1 (reference voltage: Vdet0)
A drop in voltage on VCC1 (reference voltage: Vdet1)
A drop in voltage on VCC1 (reference voltage: Vdet2)
A stop in the main clock oscillator is detected.
The watchdog timer underflows.
Setting the PM03 bit in the PM0 register to 1.
Hardware reset
Power-on reset
circuit
Voltage monitor 0 reset
Voltage monitor 1 reset
Voltage monitor 2 reset
Watchdog timer reset
Software reset
CPU
Oscillator stop detect reset
For the reset value and status, refer to 4. "Special Function Registers
(SFRs)" and 6.4.1 "Status after Reset".
Trigger
6. Resets
Registers and Bits Not to Reset
(A)
N/A
N/A
(B)
(B)
(B) (C) (D)
(B) (C)
(B) (C)
SFR (A)
SFR (B)
SFR (C)
SFR (D)
Pins, CPU, or SFRs
not listed above
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