SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 254

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SAF-C164SM

Manufacturer Part Number
SAF-C164SM
Description
16-Bit CMOS Microcontroller
Manufacturer
Infineon Technologies
Datasheet
13.2
Reset indication flags in register WDTCON provide information about the source of the
last reset. As the C164CM starts execution from location 00’0000
reset event, the initialization software may check these flags to determine if the recent
reset event was triggered by an external hardware signal (via RSTIN), by software, or by
an overflow of the watchdog timer. The initialization and further operation of the
microcontroller system can thus be adapted to the respective circumstances. For
instance, a special routine may verify software integrity after a watchdog timer reset.
The reset indication flags are not mutually exclusive; more than one flag may be set after
reset depending on its source.
Table 13-2
Event
Long Hardware Reset
Short Hardware Reset
Software Reset
Watchdog Timer Reset
EINIT instruction
SRVWDT instruction
1)
Long Hardware Reset is indicated when the RSTIN input is still sampled low (active) at
the end of a hardware triggered internal reset sequence.
Short Hardware Reset is indicated when the RSTIN input is sampled high (inactive) at
the end of a hardware triggered internal reset sequence.
Software Reset is indicated after a reset triggered by the execution of instruction SRST.
Watchdog Timer Reset is indicated after a reset triggered by an overflow of the
watchdog timer.
Note: When bidirectional reset is enabled, the RSTIN pin is pulled low for the duration of
User’s Manual
Description of table entries:
‘1’ = flag is set, ‘0’ = flag is cleared, ‘–’ = flag is not affected,
‘ ’ = flag is set in bidirectional reset mode, not affected otherwise.
the internal reset sequence upon any sort of reset.
Therefore a long hardware reset (LHWR) will always be recognized in any case.
Reset Source Indication
Reset Indication Flag Combinations
Table 13-2
LHWR
1
0
13-6
summarizes the possible combinations:
Reset Indication Flags
SHWR
1
1
0
SWR
1
1
1
1
0
Watchdog Timer (WDT)
C164CM/C164SM
H
after any possible
1)
Derivatives
WDTR
0
0
1
0
V1.0, 2002-02

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