Renesas MCU M16C Family (R32C/M32C/M16C/R8C) - Glyn

Concepts
Excellent Reliability
The M16C Family incorporates many design features to ensure reliable operation under a variety of
conditions.
On-Chip Oscillator with Fail Safe Feature
Enhanced Reliability with On-Chip Oscillator and Oscillation Stop Detection Circuit
Detects abnormal interruption of XIN oscillator input and switches to the on-chip oscillator in order to continue microcomputer operation.
Normal XIN Oscillator Input
On-Chip
Oscillator
Protecting Critical Registers
The register protect feature can
be used to safeguard access to
important registers and ports.
This can prevent unauthorized
access to key registers should
program runaway occur. It is
necessary to set the protect
register before accessing
important registers.
Grouping Together of Important Pins
The pin layout is designed to
simplify arrangement of power
supply and ground lines and
facilitate the connection of
decoupling capacitors. This also
minimizes the chances of short
circuit.
1
BYTE
Abnormal Interruption of
XIN Oscillator Input
On-Chip
Oscillator
XIN XIN XIN
CNVSS
2STOP
XCIN
XCOUT
RESET
XOUT
VSS
XIN
VCC
GND RESET
IC GND VCC
Operation Switches to
On-Chip Oscillator
CPU CPU CPU
CPU
On-Chip
Oscillator
Other Features
• It is possible to use software to halt XIN oscillator input and MCU can operate using the high-speed on-chip oscillator instead. (This also reduces power consumption.)
• The watchdog timer can operate independently using the separate low-speed (125kHz) on-chip ascillator.
Normal Operation Abnormal Operation
Protect
Register
CPU
Important Register Important Register
Grouped in one location. Minimizes chances of short circuit
NMI
*Wiring example.
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