M16C65 Datasheet, PDF (122/829 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.
7. Voltage Detector
7.3 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 is set to
FFh when the block including the optional function select area is erased.
7.3.1 Optional Function Select Address (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.
VDSEL1 (Vdet0 Select Bit 1) (b5)
The Vdet0 level used in the voltage detection 0 circuit is selectable. The voltage detection 0 circuit
operates based on Vdet0.
Set the VDSEL1 bit to 0 (Vdet0 is 2.85 V) when using power-on reset or voltage monitor 0 reset. Refer
to 6.4.10 “Cold Start-Up/Warm Start-Up Discrimination”.
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
Page 87 of 791