HT45F39 datasheet(24/102 Pages) HOLTEK

24 / 102 page

Rev. 1.10

July 01, 2016

Rev. 1.10

July 01, 2016

HT45F39/HT45F391

Ultrasonic Distance Measurement 8-bit Flash MCU

HT45F39/HT45F391

Ultrasonic Distance Measurement 8-bit Flash MCU

• FC1 Register

Bit

Name

R/W

POR

Bit7~0

SoftwareResetMCUcontrolregister

Ifthisregisterissetto"55H",itwillgeneratearesetsignaltoresetMCU.

Flash Memory Write Function Enable Procedure

InordertoallowuserstochangetheFlashmemorydatathroughtheIAPcontrolregisters,users

mustfirstenabletheFlashmemorywriteoperationbythefollowingprocedures:

• Write"110"intotheFMOD2~FMOD0bitstoselecttheFWENmode.

• SettheFWPENbitto"1".Thestep1andstep2canbeexecutedsimultaneously.

• Thepatterndatawithasequenceof00H,04H,0DH,09H,C3Hand40Hmustbewrittenintothe

FD1L,FD1H,FD2L,FD2H,FD3LandFD3Hregistersrespectively.

• Acounterwithatime-outperiodof300μswillbeactivatedtoallowuserswritingthecorrect

patterndataintotheFD1L/FD1H~FD3L/FD3Hregisterpairs.Thecounterclockisderivedfrom

LIRCoscillator.

• Ifthecounteroverflowsorthepatterndataisincorrect,theFlashmemorywriteoperationwill

notbeenabledandusersmustagainrepeattheaboveprocedure.ThentheFWPENbitwill

automaticallybeclearedto0byhardware.

• Ifthepatterndataiscorrectbeforethecounteroverflows,theFlashmemorywriteoperationwill

beenabledandtheFPWENbitwillautomaticallybeclearedto0byhardware.TheCFWENbit

willalsobesetto1byhardwaretoindicatethattheFlashmemorywriteoperationissuccessfully

enabled.

• OncetheFlashmemorywriteoperationisenabled,theusercanchangetheFlashROMdata

throughtheFlashcontrolregister.

• TodisabletheFlashmemorywriteoperation,theusercancleartheCFWENbitto0.

HT45F39 Datasheet(PDF) 24 Page - Holtek Semiconductor Inc