M16C65 Datasheet, PDF (106/829 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M16C/60

Under development
M16C/65 Group
Preliminary Specification
This is a preliminary specification and is subject to change.
6. Resets
6.4.6 Voltage Monitor 2 Reset
This reset is triggered by the MCU's on-chip voltage detection 2 circuit. The voltage detection 2 circuit
monitors the voltage applied to the VCC1 pin (Vdet2).
When the VW2C6 bit in the VW2C register is 1 (voltage monitor 2 reset when Vdet2 passage is
detected), the MCU resets the pins, CPU, and SFRs when the voltage applied to the VCC1 pin drops to
Vdet2 or below. Then, after the set amount of time, the MCU executes the program at the address
indicated by the reset vector. The fOCO-S divided by 8 is automatically selected as the CPU clock after
reset.
The LVD2R bit in the RSTFR register becomes 1 (voltage monitor 2 reset detected) after voltage
monitor 2 reset. Some SFRs are not reset at voltage monitor 2 reset. Refer to 4. “Special Function
Registers (SFRs)” for details. The processor mode remains unchanged since bits PM01 to PM00 in the
PM0 register are not reset.
The internal RAM is not reset.
Refer to 7. “Voltage Detector” for details of the voltage monitor 2 reset.
6.4.7 Oscillation Stop Detection Reset
The MCU resets and stops the pins, CPU, and SFRs when the CM27 bit in the CM2 register is 0 (reset
when oscillation stop detected), if it detects that the main clock oscillator has stopped.
The OSDR bit in the RSTFR register becomes 1 (oscillation stop detection reset detected).
Some SFRs are not reset at oscillation stop detection reset. Refer to 4. “Special Function Registers
(SFRs)” for details. The processor mode remains unchanged since bits PM01 to PM00 in the PM0
register are not reset.
The internal RAM is not reset. When the main clock oscillation stop is detected while writing data to the
internal RAM, the internal RAM is in an undefined state.
Oscillation stop detection reset is canceled by hardware reset or voltage monitor 0 reset.
Refer to 8.7 “Oscillation Stop/Re-Oscillation Detect Function” for details.
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
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