Holtek HT66F0175 - Page 159

Rev. 1.50 158 August 28, 2017 Rev. 1.50 159 August 28, 2017
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
UCR1 Register
TheUCR1registertogetherwiththeUCR2registeraretheUARTcontrolregistersthatareused
tosetthevariousoptionsfortheUARTfunctionsuchasoverallon/offcontrol,paritycontrol,data
transferbitlength,etc.Furtherexplanationoneachofthebitsisgivenbelow.
Bit 7 6 5 4 3 2 1 0
Name UARTEN BNO PREN PRT STOPS TXBRK RX8 TX8
R/W R/W R/W R/W R/W R/W R/W R W
POR 0 0 0 0 0 0 x 0
“x”: unknown
Bit7 UARTEN:UARTfunctionenablecontrol
0:DisableUART;TXandRXpinsareusedasotherpin-sharedfunctionalpins.
1:EnableUART;TXandRXpinscanfunctionasUARTpinsdenedbyTXENand
RXENbits
TheUARTENbitistheUARTenablebit.Whenthisbitisequalto“0”,theUARTwill
bedisabledandtheRXpinaswellastheTXpinwillbeotherpin-sharedfunctional
pins.Whenthebitisequalto“1”,theUARTwillbeenabledandtheTXandRXpins
willfunctionasdenedbytheTXENandRXENenablecontrolbits.WhentheUART
isdisabled,itwillemptythebuffersoanycharacterremaininginthebufferwillbe
discarded.Inaddition,thevalueofthebaudratecounterwillbereset.IftheUART
isdisabled,allerrorandstatusagswillbereset.AlsotheTXEN,RXEN,TXBRK,
RXIF,OERR,FERR,PERRandNFbitswillbecleared,whiletheTIDLE,TXIFand
RIDLEbitswillbeset.OthercontrolbitsinUCR1,UCR2andBRGregisterswill
remainunaffected.IftheUARTisactiveandtheUARTENbitiscleared,allpending
transmissionsandreceptionswillbeterminatedandthemodulewillberesetasdened
above.WhentheUARTisre-enabled,itwillrestartinthesameconguration.
Bit6 BNO:Numberofdatatransferbitsselection
0:8-bitdatatransfer
1:9-bitdatatransfer
Thisbitisusedtoselectthedatalengthformat,whichcanhaveachoiceofeither
8-bitor9-bitformat.Whenthisbitisequalto“1”,a9-bitdatalengthformatwillbe
selected.Ifthebitisequalto“0”,thenan8-bitdatalengthformatwillbeselected.If
9-bitdatalengthformatisselected,thenbitsRX8andTX8willbeusedtostorethe9
th

bitofthereceivedandtransmitteddatarespectively.
Bit5 PREN:Parityfunctionenablecontrol
0:Parityfunctionisdisabled
1:Parityfunctionisenabled
Thisbitistheparityfunctionenablebit.Whenthisbitisequalto1,theparityfunction
willbeenabled.Ifthebitisequalto0,thentheparityfunctionwillbedisabled.
Bit4 PRT:Paritytypeselectionbit
0:Evenparityforparitygenerator
1:Oddparityforparitygenerator
Thisbitistheparitytypeselectionbit.Whenthisbitisequalto1,oddparitytypewill
beselected.Ifthebitisequalto0,thenevenparitytypewillbeselected.
Bit3 STOPS:Numberofstopbitsselection
0:Onestopbitformatisused
1:Twostopbitsformatisused
Thisbitdeterminesifoneortwostopbitsaretobeused.Whenthisbitisequalto“1”,
twostopbitsformatareused.Ifthebitisequalto“0”,thenonlyonestopbitformatis
used.