MC68HC08XL36 Datasheet, PDF (294/362 Pages) Freescale Semiconductor, Inc – HCMOS Microcontroller Unit

COP
Freescale Semiconductor, Inc.
Functional Description
CGMXCLK
12-BIT COP PRESCALER
STOP INSTRUCTION
INTERNAL RESET SOURCES
RESET VECTOR FETCH
COPCTL WRITE
COP DISABLE
(MASK OPTION)
RESET
COPCTL WRITE
COP TIMEOUT PERIOD
(MASK OPTION)
6-BIT COP COUNTER
CLEAR COP
COUNTER
RESET
RESET STATUS
REGISTER
Figure 1. COP Block Diagram
The COP counter is a free-running 6-bit counter preceded by a 12-bit
prescaler. If not cleared by software, the COP counter overflows and
generates an asynchronous reset after 2¹³ – 2⁴ or 2¹⁸ – 2⁴ CGMXCLK
cycles, depending on the mask option selected for COP timeout period.
With the 2¹⁸ – 2⁴ CGMXCLK cycle overflow option, a 4.9152-MHz
crystal gives a COP timeout period of 53.3 ms. Writing any value to
location $FFFF before an overflow occurs prevents a COP reset by
clearing the COP counter and stages 5 through 12 of the prescaler.
MC68HC08XL36
294
Computer Operating Properly Module (COP)
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Go to: www.freescale.com
2-copopt2_b
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