R01UH0092EJ0110 Rev.1.10
Page 229 of 807
Jul 31, 2012
M16C/64C Group
15. Watchdog Timer
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)
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).
Optional Function Select Address 1
b7
1
1
b6 b5 b4
b1
b2
b3
Symbol
OFS1
Address
FFFFFh
Bit Symbol
Bit Name
b0
Function
WDTON
Watchdog timer start select bit
0 : Watchdog timer starts automatically
after reset
1 : Watchdog timer is stopped after reset
—
(b1)
Reserved bit
Set to 1.
CSPROINI
After-reset count source
protection mode select bit
0 : Count source protection mode
enabled after reset
1 : Count source protection mode
disabled after reset
ROMCR
ROM code protect cancel bit
0 : ROM code protection cancelled
1 : ROMCP1 bit enabled
ROMCP1
ROM code protect bit
0 : ROM code protection enabled
1 : ROM code protection disabled
—
(b4)
Reserved bit
Set to 1.
VDSEL1
Vdet0 select bit 1
0 : Vdet0_2
1 : Vdet0_0
LVDAS
Voltage detector 0 start bit
0 : Voltage monitor 0 reset enabled
after hardware reset
1 : Voltage monitor 0 reset disabled
after hardware reset
Содержание M16C Series
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