Rev. 1.50 60 August 28, 2017 Rev. 1.50 61 August 28, 2017
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
Watchdog Time-out Reset during Normal Operation
TheWatchdogtime-outResetduringnormaloperationisthesameasthehardwareLowVoltage
ResetexceptthattheWatchdogtime-outagTOwillbesetto“1”.
WDT Time-out
Internal Reset
t
RSTD
+ t
SST
Note:t
RSTD
ispower-ondelaywithtypicaltime=16.7ms
WDT Time-out Reset during NORMAL Operation Timing Chart
Watchdog Time-out Reset during SLEEP or IDLE Mode
TheWatchdogtime-outResetduringSLEEPorIDLEModeisalittledifferentfromotherkinds
ofreset.MostoftheconditionsremainunchangedexceptthattheProgramCounterandtheStack
Pointerwillbeclearedto“0”andtheTOagwillbesetto“1”.RefertotheA.C.Characteristicsfor
t
SST
details.
WDT Time-out
Internal Reset
t
SST
WDT Time-out Reset during SLEEP or IDLE Mode Timing Chart
Reset Initial Conditions
Thedifferenttypesofresetdescribedaffecttheresetagsindifferentways.Theseags,known
asPDFandTOarelocatedinthestatusregisterandarecontrolledbyvariousmicrocontroller
operations,suchastheSLEEPorIDLEModefunctionorWatchdogTimer.Theresetflagsare
showninthetable:
TO PDF Reset Function
0 0 Power-on reset
u u LVR reset during NORMAL or SLOW Mode operation
1 u WDT time-out reset during NORMAL or SLOW Mode operation
1 1 WDT time-out reset during IDLE or SLEEP Mode operation
“u” stands for unchanged
Thefollowingtableindicatesthewayinwhichthevariouscomponentsofthemicrocontrollerare
affectedafterapower-onresetoccurs.
Item Reset Function
Program Counter Reset to zero
Interrupts All interrupts will be disabled
WDT, Time Base Clear after reset, WDT begins counting
Timer Modules Timer Modules will be turned off
Input/Output Ports I/O ports will be setup as inputs
Stack pointer Stack pointer will point to the top of the stack
Thedifferentkindsofresetsallaffecttheinternalregistersofthemicrocontrollerindifferentways.
Toensurereliablecontinuationofnormalprogramexecutionafteraresetoccurs,itisimportantto
knowwhatconditionthemicrocontrollerisinafteraparticularresetoccurs.Thefollowingtable
describeshoweachtypeofresetaffectsthemicrocontrollerinternalregisters.Notethatwheremore
thanonepackagetypeexiststhetablewillreectthesituationforthelargerpackagetype.