Holtek HT66F0175 - Page 98

Rev. 1.50 98 August 28, 2017 Rev. 1.50 99 August 28, 2017
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
Single Pulse Output Mode
Toselectthismode,bitsTnM1andTnM0intheTMnC1registershouldbesetto10respectively
andalsotheTnIO1andTnIO0bitsshouldbesetto11respectively.TheSinglePulseOutputMode,
asthenamesuggests,willgenerateasingleshotpulseontheTMnoutputpin.
ThetriggerforthepulseoutputleadingedgeisalowtohightransitionoftheTnONbit,whichcan
beimplementedusingtheapplicationprogram.HoweverintheSinglePulseMode,theTnONbit
canalsobemadetoautomaticallychangefromlowtohighusingtheexternalTCKnpin,whichwill
inturninitiatetheSinglePulseoutput.WhentheTnONbittransitionstoahighlevel,thecounter
willstartrunningandthepulseleadingedgewillbegenerated.TheTnONbitshouldremainhigh
whenthepulseisinitsactivestate.Thegeneratedpulsetrailingedgewillbegeneratedwhenthe
TnONbitisclearedtozero,whichcanbeimplementedusingtheapplicationprogramorwhena
comparematchoccursfromComparatorA.
HoweveracomparematchfromComparatorAwillalsoautomaticallycleartheTnONbitandthus
generatetheSinglePulseoutputtrailingedge.InthiswaytheCCRAvaluecanbeusedtocontrolthe
pulsewidth.AcomparematchfromComparatorAwillalsogenerateaTMninterrupt.Thecounter
canonlyberesetbacktozerowhentheTnONbitchangesfromlowtohighwhenthecounter
restarts.IntheSinglePulseModeCCRPisnotused.TheTnCCLRandTnDPXbitsarenotusedin
thisMode.
TnON bit
0 à 1
S/W Command
SET“TnON”
or
TCKn Pin
Transition
TnON bit
1 à 0
CCRA
Trailing Edge
S/W Command
CLR“TnON”
or
CCRA Compare
Match
TPn Output Pin
Pulse Width = CCRA Value
CCRA
Leading Edge
Single Pulse Generation