HT67F488 datasheet(36/171 Pages) HOLTEK

36 / 171 page

Rev. 1.60

�ove��e� �� 016

HT67F488/HT67F489

TinyPowerTM A/D Flash MCU with LCD & EEPROM

Programming Considerations

CaremustbetakenthatdataisnotinadvertentlywrittentotheEEPROM.Protectioncanbe

enhancedbyensuringthattheWriteEnablebitisnormallyclearedtozerowhennotwriting.

AlsotheMemoryPointerhighbyte,MP1HorMP2H,couldbenormallyclearedtozeroasthis

wouldinhibitaccesstoSector1wheretheEEPROMcontrolregisterexist.Althoughcertainlynot

necessary,considerationmightbegivenintheapplicationprogramtothecheckingofthevalidity

ofnewwritedatabyasimplereadbackprocess.WhenwritingdatatheWRbitmustbesethigh

immediatelyaftertheWRENbithasbeensethigh,toensurethewritecycleexecutescorrectly.The

globalinterruptbitEMIshouldalsobeclearedbeforeawritecycleisexecutedandthenre-enabled

afterthewritecyclestarts.NotethatthedeviceshouldnotentertheIDLEorSLEEPmodeuntil

theEEPROMreadorwriteoperationistotallycomplete.Otherwise,theEEPROMreadorwrite

operationwillfail.

Programming Examples

Reading data from the EEPROM - polling method

MOV A,EEPROM_ADRES;userdefinedaddress

MOV EEA,A

MOV A,040H;setupmemorypointerMP1L

MOV MP1L,A;MP1pointstoEECregister

MOV A,01H;setupmemorypointerMP1H

MOV MP1H,A

SET IAR1.1;setRDENbit,enablereadoperations

SET IAR1.0;startReadCycle-setRDbit

BACK:

SZ IAR1.0;checkforreadcycleend

JMP BACK

CLR IAR1 ;disableEEPROMread/write

CLR MP1H

MOV A,EED;movereaddatatoregister

MOV READ_DATA,A

Writing Data to the EEPROM - polling method

MOV A,EEPROM_ADRES;userdefinedaddress

MOV EEA,A

MOV A,EEPROM_DATA;userdefineddata

MOV EED,A

MOV A,040H;setupmemorypointerMP1L

MOV MP1L,A;MP1pointstoEECregister

MOV A,01H;setupmemorypointerMP1H

MOV MP1H,A

CLR EMI

SET IAR1.3;setWRENbit,enablewriteoperations

SET IAR1.2;startWriteCycle-setWRbit–executedimmediatelyafter

set WRENbit

SET EMI

BACK:

SZ IAR1.2;checkforwritecycleend

JMP BACK

CLR IAR1 ;disableEEPROMread/write

CLR MP1H

HT67F488 датащи(PDF) 36 Page - Holtek Semiconductor Inc

HT67F488 датащи(HTML) 36 Page - Holtek Semiconductor Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL