mc68hc908kx8 Freescale Semiconductor, Inc, mc68hc908kx8 Datasheet - Page 53

• Manufacturer Part Number: mc68hc908kx8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

5.4.6 Reset Vector Fetch
A reset vector fetch occurs when the vector address appears on the data bus. A reset vector fetch clears
the COP prescaler.
5.4.7 COPD (COP Disable)
The COPD signal reflects the state of the COP disable bit (COPD) in the configuration register. See
Chapter 4 Configuration Register
5.4.8 COPRS (COP Rate Select)
The COPRS signal reflects the state of the COP rate select bit (COPRS) in the configuration register. See
Chapter 4 Configuration Register
5.5 COP Control Register
The COP control register (COPCTL) is located at address $FFFF and overlaps the reset vector. Writing
any value to $FFFF clears the COP counter and stages 12–5 of the COP prescaler and starts a new
timeout period. Reading location $FFFF returns the low byte of the reset vector.
5.6 Interrupts
The COP does not generate CPU interrupt requests.
5.7 Monitor Mode
The COP is disabled in monitor mode when V
5.8 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-consumption standby modes.
5.8.1 Wait Mode
The COP remains active in wait mode. To prevent a COP reset during wait mode, periodically clear the
COP counter in a CPU interrupt routine.
Freescale Semiconductor
Address: $FFFF
Reset:
Read:
Write:
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
Bit 7
Figure 5-2. COP Control Register (COPCTL)
(CONFIG).
(CONFIG).
6
5
TST
Low byte of reset vector
Unaffected by reset
is present on the IRQ1 pin.
Clear COP counter
4
3
2
1
COP Control Register
Bit 0
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