MC68HC12 Datasheet, PDF (192/478 Pages) Motorola, Inc – The MC68HC912DT128A microcontroller unit (MCU) is a 16-bit device composed of standard on-chip peripherals including a 16-bit central processing unit

Clock Functions
Bit 7
6
5
4
3
2
1
Bit 0
Bit 7
6
5
4
3
2
1
Bit 0
RESET:
0
0
0
0
0
0
0
0
COPRST — Arm/Reset COP Timer Register
$0017
Always reads $00.
Writing $55 to this address is the first step of the COP watchdog
sequence.
Writing $AA to this address is the second step of the COP watchdog
sequence. Other instructions may be executed between these writes
but both must be completed in the correct order prior to time-out to
avoid a watchdog reset. Writing anything other than $55 or $AA
causes a COP reset to occur.
Technical Data
192
Clock Functions
MC68HC912DT128A — Rev 4.0
MOTOROLA