M16C65 Datasheet, PDF (98/829 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
6.3 Optional Function Select Area
In the optional function select area, the MCU state after reset and the function to prevent rewrite in parallel
I/O mode are selected.
The optional function select area is not an SFR, and therefore cannot be rewritten by a program. Set a
proper value when writing a program in flash memory. The entire optional function select area becomes
FFh when the block including the optional function select area is erased.
6.3.1 Optional Function Select Address 1 (OFS1)
Optional Function Select Address 1
b7 b6 b5 b4 b3 b2 b1 b0
1
1
Symbol
OFS1
Address
FFFFFh
Factory Setting
FFh
Bit Symbol
Bit Name
Function
RW
0 : Watchdog timer starts automatically
WDTON
Watchdog timer start select bit
after reset.
1 : Watchdog timer is in a stopped state
RW
after reset.
—
(b1)
Reserved bit
Set to 1.
RW
ROMCR ROM code protect cancel bit
0 : ROM code protection cancelled.
1 : ROMCP1 bit enabled.
RW
ROMCP1 ROM code protect bit
0 : ROM code protection enabled.
1 : ROM code protection disabled.
RW
—
(b4)
Reserved bit
Set to 1.
RW
VDSEL1 Vdet0 select bit 1
0 : 2.85 V (Vdet0_2)
1 : 1.90 V (Vdet0_0)
RW
0 : Voltage monitor 0 reset enabled
LVDAS
Voltage detection 0 circuit
start bit
after hardware reset.
1 : Voltage monitor 0 reset disabled
RW
after hardware reset.
0 : Count source protection mode
CSPROINI
After-reset count source
protection mode select bit
enabled after reset.
1 : Count source protection mode
RW
disabled after reset.
WDTON (Watchdog Timer Start Select Bit) (b0)
CSPROINI (After-Reset Count Source Protection Mode Select Bit) (b7)
These bits select the state of watchdog timer after reset.
Set the WDTON bit to 0 (watchdog timer starts automatically after reset) when setting the CSPROINI bit
to 0 (count source protection mode enabled after reset).
Refer to 15. “Watchdog Timer” for details of the watchdog timer and count source protection mode.
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
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