HT45F12
8-Bit Flash MCU with Op Amps & Comparators
EEPROM Data Memory
OneꢀofꢀtheꢀspecialꢀfeaturesꢀinꢀtheꢀdeviceꢀisꢀitsꢀinternalꢀEEPROMꢀDataꢀMemory.ꢀEEPROM,ꢀwhichꢀ
standsꢀforꢀElectricallyꢀErasableꢀProgrammableꢀReadꢀOnlyꢀMemory,ꢀisꢀbyꢀitsꢀnatureꢀaꢀnon-volatileꢀ
formꢀofꢀmemory,ꢀwithꢀdataꢀretentionꢀevenꢀwhenꢀitsꢀpowerꢀsupplyꢀisꢀremoved.ꢀByꢀincorporatingꢀ
thisꢀkindꢀofꢀdataꢀmemory,ꢀaꢀwholeꢀnewꢀhostꢀofꢀapplicationꢀpossibilitiesꢀareꢀmadeꢀavailableꢀtoꢀtheꢀ
designer.ꢀTheꢀavailabilityꢀofꢀEEPROMꢀstorageꢀallowsꢀinformationꢀsuchꢀasꢀproductꢀidentificationꢀ
numbers,ꢀcalibrationꢀvalues,ꢀspecificꢀuserꢀdata,ꢀsystemꢀsetupꢀdataꢀorꢀotherꢀproductꢀinformationꢀtoꢀ
beꢀstoredꢀdirectlyꢀwithinꢀtheꢀproductꢀmicrocontroller.ꢀTheꢀprocessꢀofꢀreadingꢀandꢀwritingꢀdataꢀtoꢀtheꢀ
EEPROMꢀmemoryꢀhasꢀbeenꢀreducedꢀtoꢀaꢀveryꢀtrivialꢀaffair.
EEPROM Data Memory Structure
TheꢀEEPROMꢀDataꢀMemoryꢀcapacityꢀisꢀ32×8ꢀbits.ꢀUnlikeꢀtheꢀProgramꢀMemoryꢀandꢀRAMꢀDataꢀ
Memory,ꢀtheꢀEEPROMꢀDataꢀMemoryꢀisꢀnotꢀdirectlyꢀmappedꢀandꢀisꢀthereforeꢀnotꢀdirectlyꢀaccessibleꢀ
inꢀsameꢀwayꢀasꢀtheꢀotherꢀtypesꢀofꢀmemory.ꢀReadꢀandꢀWriteꢀoperationsꢀtoꢀtheꢀEEPROMꢀareꢀcarriedꢀ
outꢀinꢀsingleꢀbyteꢀoperationsꢀusingꢀanꢀaddressꢀandꢀdataꢀregisterꢀinꢀBankꢀ0ꢀandꢀaꢀsingleꢀcontrolꢀ
registerꢀinꢀBankꢀ1.
EEPROM Registers
ThreeꢀregistersꢀcontrolꢀtheꢀoverallꢀoperationꢀofꢀtheꢀinternalꢀEEPROMꢀDataꢀMemory.ꢀTheseꢀareꢀtheꢀ
addressꢀregister,ꢀEEADDR,ꢀtheꢀdataꢀregister,ꢀEEDATAꢀandꢀaꢀsingleꢀcontrolꢀregister,ꢀEECTRL.ꢀAsꢀ
bothꢀtheꢀEEADDRꢀandꢀEEDATAꢀregistersꢀareꢀlocatedꢀinꢀBankꢀ0,ꢀtheyꢀcanꢀbeꢀdirectlyꢀaccessedꢀinꢀtheꢀ
sameꢀwayꢀasꢀanyꢀotherꢀSpecialꢀFunctionꢀRegister.ꢀTheꢀEECTRLꢀregisterꢀhowever,ꢀbeingꢀlocatedꢀinꢀ
Bank1,ꢀcannotꢀbeꢀdirectlyꢀaddressedꢀdirectlyꢀandꢀcanꢀonlyꢀbeꢀreadꢀfromꢀorꢀwrittenꢀtoꢀindirectlyꢀusingꢀ
theꢀMP1ꢀMemoryꢀPointerꢀandꢀIndirectꢀAddressingꢀRegister,ꢀIAR1.ꢀBecauseꢀtheꢀEECTRLꢀcontrolꢀ
registerꢀisꢀlocatedꢀatꢀaddressꢀ40HꢀinꢀBankꢀ1,ꢀtheꢀMP1ꢀMemoryꢀPointerꢀmustꢀfirstꢀbeꢀsetꢀtoꢀtheꢀvalueꢀ
40HꢀandꢀtheꢀBankꢀPointerꢀregister,ꢀBP,ꢀsetꢀtoꢀtheꢀvalue,ꢀ01H,ꢀbeforeꢀanyꢀoperationsꢀonꢀtheꢀEECTRLꢀ
registerꢀareꢀexecuted.
EEPROM Control Registers List
Bit
Name
7
6
5
4
3
D3
2
1
D1
0
EEADDR
EEDATA
EECTRL
—
D7
—
—
Dꢅ
—
—
D5
—
D4
D4
—
Dꢄ
Dꢄ
WT
D0
D0
RD
D3
D1
WTEN
RDEN
EEADDR Register
Bit
Naꢁe
R/W
7
6
5
4
D4
R/W
0
3
D3
R/W
0
2
Dꢄ
R/W
0
1
D1
R/W
0
0
D0
R/W
0
—
—
—
—
—
—
—
—
—
POR
Bitꢀ7~5ꢀ
Bitꢀ4~0ꢀ
ꢀ
Unimplemented,ꢀreadꢀasꢀ"0"
DataꢀEEPROMꢀaddress
DataꢀEEPROMꢀaddressꢀbitꢀ4ꢀ~ꢀbitꢀ0
Rev. 0.00
ꢄ9
�eꢀteꢁꢂeꢃ ꢄꢅꢆ ꢄ01ꢄ
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
