M30100 Datasheet, PDF (59/164 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

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Tentative Specifications REV.E1
Specifications in this manual are tentative
and
subject
to
change.
Watchdog Timer
Mitsubishi microcomputers
M30100/M30102 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Watchdog timer control register
b7 b6 b5 b4 b3 b2 b1 b0
00
Symbol
WDC
Address
000F16
Bit symbol
Bit name
High-order bit of watchdog timer
Reserved bit
Reserved bit
WDC7
Prescaler select bit
When reset
000XXXXX2
Function
Must always be set to “0”
Must always be set to “0”
0 : Divided by 16
1 : Divided by 128
RW
Watchdog timer start register
b7
b0
Symbol
WDTS
Address
000E16
When reset
Indeterminate
Function
RW
The watchdog timer is initialized and starts counting after a write instruction to
this register. The watchdog timer value is always initialized to “7FFF16”
regardless of whatever value is written.
Processor mode register 1 (Note 1)
b7 b6 b5 b4 b3 b2 b1 b0
00
0
Symbol
PM1
Address
000516
When reset
00XXX0X02
Bit symbol
Bit name
Function
RW
Reserved bit
Must always be set to “0”
Nothing is assigned.
In an attempt to write to this bits, write “0”. The value, if read, turns
out to be indeterminate.
PM12
WDT interrupt/reset
switching bit
0 : Watchdog timer interrupt
1 : Reset (Note 2)
Nothing is assigned.
In an attempt to write to these bits, write “0”. The value, if read, turns
out to be indeterminate.
Reserved bit
Must always be set to “0”
Note 1: Set bit 1 of the protect register (address 000A16) to “1” when writing new
values to this register.
Note 2: After setting this bit to "1", can not change to "0" by software.
Figure 1.13.2. Watchdog timer control and start registers
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