Computer Operating Properly (COP)
COP Control Register
MC68HC908GP32
•
MC68HC08GP32
—
Rev. 6
Technical Data
MOTOROLA
Computer Operating Properly (COP)
145
9.5 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.
9.6 Interrupts
The COP does not generate CPU interrupt requests.
9.7 Monitor Mode
When monitor mode is entered with V
TST
on the IRQ pin, the COP is
disabled as long as V
TST
remains on the IRQ pin or the RST pin. When
monitor mode is entered by having blank reset vectors and not having
V
TST
on the IRQ pin, the COP is automatically disabled until a POR
occurs.
9.8 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-
consumption standby modes.
Address:
$FFFF
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Low byte of reset vector
Write:
Clear COP counter
Reset:
Unaffected by reset
Figure 9-2. COP Control Register (COPCTL)
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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