Holtek HT66F002 - Flash Program Memory; Structure; Look-up Table

Rev. 1.71 22 April 11, 2017 Rev. 1.71 23 April 11, 2017
HT66F002/HT66F0025/HT66F003/HT66F004
Cost-Effective A/D Flash MCU with EEPROM
HT66F002/HT66F0025/HT66F003/HT66F004
Cost-Effective A/D Flash MCU with EEPROM
Flash Program Memory
TheProgramMemoryisthelocationwheretheusercodeorprogramisstored.Forthesedevicesthe
ProgramMemoryareFlashtype,whichmeansitcanbeprogrammedandre-programmedalarge
numberoftimes,allowingtheusertheconvenienceofcodemodificationonthesamedevice.By
usingtheappropriateprogrammingtools,theseFlashdevicesofferuserstheexibilitytoconveniently
debuganddeveloptheirapplicationswhilealsoofferingameansofeldprogrammingandupdating.
Device Capacity
HT66F002/HT66F003 1K
×
14
HT66F0025 2K
×
14
HT66F004 2K
×
15
Structure
TheProgramMemoryhasacapacityof1K×14,2K×14or2K×15bits.TheProgramMemoryis
addressedbytheProgramCounterandalsocontainsdata,tableinformationandinterruptentries.Table
data,whichcanbesetupinanylocationwithintheProgramMemory,isaddressedbyaseparatetable
pointerregister.
000H
Initialisation Vector
004H
3FFH
14 bits
Interrupt Vectors
Look-up Table
n00H
nFFH
HT66F002
Initialisation Vector
14 bits
Interrupt Vectors
Look-up Table
Initialisation Vector
15 bits
Interrupt Vectors
Look-up Table
7FFH
01CH
HT66F003 HT66F004
018H
Initialisation Vector
14 bits
Interrupt Vectors
Look-up Table
HT66F0025
7FFH
Program Memory Structure
Special Vectors
WithintheProgramMemory,certainlocationsarereservedfortheresetandinterrupts.Thelocation
000Hisreservedforusebythesedevicesresetforprograminitialisation.Afteradeviceresetis
initiated,theprogramwilljumptothislocationandbeginexecution.
Look-up Table
AnylocationwithintheProgramMemorycanbedenedasalook-uptablewhereprogrammerscan
storexeddata.Tousethelook-uptable,thetablepointermustrstbesetupbyplacingtheaddress
ofthelookupdatatoberetrievedinthetablepointerregister,TBLP.Thisregisterdenesthetotal
addressofthelook-uptable.
Aftersettingupthetablepointer,thetabledatacanberetrievedfromtheProgramMemoryusing
the“TABRD[m]”or“TABRDL[m]”instructions,respectively.Whentheinstructionisexecuted,
thelowerordertablebytefromtheProgramMemorywillbetransferredtotheuserdefined
DataMemoryregister[m]asspecifiedintheinstruction.Thehigherordertabledatabytefrom
theProgramMemorywillbetransferredtotheTBLHspecialregister.Anyunusedbitsinthis
transferredhigherorderbytewillbereadas“0”.