MC68HC908GT16_07 FREESCALE [Freescale Semiconductor, Inc], MC68HC908GT16_07 Datasheet - Page 63

• Manufacturer Part Number: MC68HC908GT16_07
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

5.3.6 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.
5.3.7 COPD (COP Disable)
The COPD signal reflects the state of the COP disable bit (COPD) in the configuration register. See
Chapter 4 Configuration Register (CONFIG).
5.3.8 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 (CONFIG).
5.4 COP Control Register
The COP control register is located at address $FFFF and overlaps the reset vector. Writing any value to
$FFFF clears the COP counter and starts a new timeout period. Reading location $FFFF returns the low
byte of the reset vector.
5.5 Interrupts
The COP does not generate central processor unit (CPU) interrupt requests.
5.6 Monitor Mode
When monitor mode is entered with V
on the IRQ pin or the RST pin. When monitor mode is entered by having blank reset vectors and not
having V
5.7 Low-Power Modes
The WAIT and STOP instructions put the microcontroller unit (MCU) in low power-consumption standby
modes.
5.7.1 Wait Mode
The COP remains active during wait mode. To prevent a COP reset during wait mode, periodically clear
the COP counter in a CPU interrupt routine.
Freescale Semiconductor
TST
on the IRQ pin, the COP is automatically disabled until a POR occurs.
Address: $FFFF
Reset:
Read:
Write:
MC68HC908GT16 • MC68HC908GT8 • MC68HC08GT16 Data Sheet, Rev. 5.0
Bit 7
Figure 5-2. COP Control Register (COPCTL)
6
TST
on the IRQ pin, the COP is disabled as long as V
5
Low byte of reset vector
Unaffected by reset
Clear COP counter
4
3
2
1
COP Control Register
Bit 0
TST
remains
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