mc68hc705e5 Freescale Semiconductor, Inc, mc68hc705e5 Datasheet - Page 46

• Manufacturer Part Number: mc68hc705e5
• Description: M68hc05 Family Of Microcontrollers Mcus
• Manufacturer: Freescale Semiconductor, Inc

Resets
5.6.4 COP Watchdog Timer Considerations
5.7 Illegal Address Reset
General Release Specification
If enabled by a mask option, the COP watchdog timer is active in all
modes of operation (disabled in test and self-check modes). If the COP
watchdog timer is selected by a mask option, any execution of the STOP
instruction (either intentional or inadvertent due to the CPU being
disturbed) will cause the oscillator to halt and prevent the COP watchdog
timer from timing out. Therefore, it is recommended that the STOP
instruction should be disabled if the COP watchdog timer is enabled.
If the COP watchdog timer is selected by a mask option, the COP will
reset the MCU when it times out. Therefore, it is recommended that the
COP watchdog should be disabled for a system that must have
intentional uses of the wait mode for periods longer than the COP
timeout period.
The recommended interactions and considerations for the COP
watchdog timer, STOP instruction, and WAIT instruction are
summarized in
When an opcode fetch occurs from an address which is not implemented
in the RAM ($0080–$01FF) or ROM ($0F00–$1FFF), the part is reset
automatically.
Converted to Reset
Converted to Reset
STOP Instruction
Freescale Semiconductor, Inc.
Acts as STOP
IF the Following Conditions Exist:
For More Information On This Product,
Table 5-1. COP Watchdog Timer Recommendations
Go to: www.freescale.com
Figure
Resets
5-1.
COP Time-Out
COP Time-Out
Any Length
WAIT Time
WAIT Time
WAIT Time
More Than
Wait Time
Less Than
Disable COP by Mask Option
Disable COP by Mask Option
THEN the COP Watchdog
Enable or Disable COP
Timer Should Be:
MC68HC705E5
by Mask Option
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Rev. 1.0