Optional Function Select Area; Optional Function Select Address 1 (Ofs1) - Renesas M16C/64C User Manual

M16C/64C Group
15.3

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 an
appropriate value when writing a program to flash memory. The entire optional function select area
becomes FFh when the block including the optional function select area is erased.
In blank products, the OFS1 address value is FFh when shipped. After a value is written by the user, this
register takes on the written value. In programmed products, the OFS1 address is the value set in the
user program prior to shipping.
Selection using the optional function select area can be used in single-chip mode or memory expansion
mode. The option function select area cannot be used in microprocessor mode. When using the MCU in
microprocessor mode, clear the internal ROM.
15.3.1

Optional Function Select Address 1 (OFS1)

Optional Function Select Address 1
b7 b6 b5 b4 b3
1
WDTON (Watchdog timer start select bit) (b0)
CSPROINI (After-reset count source protection mode select bit) (b7)
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).
R01UH0092EJ0110 Rev.1.10
Jul 31, 2012
Symbol
b2 b1 b0
1
OFS1
Bit Symbol
WDTON Watchdog timer start select bit
—
Reserved bit
(b1)
ROMCR ROM code protect cancel bit
ROMCP1 ROM code protect bit
—
Reserved bit
(b4)
VDSEL1 Vdet0 select bit 1
LVDAS Voltage detector 0 start bit
After-reset count source
CSPROINI
protection mode select bit
Address
FFFFFh
Bit Name
0 : Watchdog timer starts automatically
after reset
1 : Watchdog timer is stopped after reset
Set to 1.
0 : ROM code protection cancelled
1 : ROMCP1 bit enabled
0 : ROM code protection enabled
1 : ROM code protection disabled
Set to 1.
0 : Vdet0_2
1 : Vdet0_0
0 : Voltage monitor 0 reset enabled
after hardware reset
1 : Voltage monitor 0 reset disabled
after hardware reset
0 : Count source protection mode
enabled after reset
1 : Count source protection mode
disabled after reset
15. Watchdog Timer
Function
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