Holtek HT66F0175 - Page 122

Rev. 1.50 122 August 28, 2017 Rev. 1.50 123 August 28, 2017
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
• SADC2 Register
Bit 7 6 5 4 3 2 1 0
Name ADPGAEN VBGEN VREFIPS VREFPS SAVRS3 SAVRS2 SAVRS1 SAVRS0
R/W R/W R/W R/W R/W R/W R/W R/W R/W
POR 0 0 0 0 0 0 0 0
Bit7 ADPGAEN:A/DconverterPGAfunctionenablecontrol
0:Disable
1:Enable
ThisbitcontrolstheinternalPGAfunctiontoprovidevariousreferencevoltagefor
theA/Dconverter.Whenthebitissethigh,theinternalreferencevoltage,V
R
,canbe
usedastheinternalconvertedsignalorreferencevoltagebytheA/Dconverter.Ifthe
internalreferencevoltageisnotusedbytheA/Dconverter,thenthePGAfunction
shouldbeproperlyconguredtoconservepower.
Bit6 VBGEN:InternalBandgapreferencevoltageenablecontrol
0:Disable
1:Enable
ThisbitcontrolstheinternalBandgapcircuiton/offfunctiontotheA/Dconverter.
Whenthebitissethigh,theBandgapreferencevoltagecanbeusedbytheA/D
converter.IftheBandgapreferencevoltageisnotusedbytheA/Dconverterand
theLVDorLVRfunctionisdisabled,thenthebandgapreferencecircuitwillbe
automaticallyswitchedofftoconservepower.WhentheBandgapreferencevoltage
isswitchedonforusebytheA/Dconverter,atime,t
BGS
,shouldbeallowedforthe
BandgapcircuittostabilisebeforeimplementinganA/Dconversion.
Bit5 VREFIPS:VREFIpinselectionbit
0:Disable–VREFIpinisnotselected
1:Enable–VREFIpinisselected
Bit4 VREFPS:VREFpinselectionbit
0:Disable–VREFpinisnotselected
1:Enable–VREFpinisselected
Bit3~0 SAVRS3~SAVRS0:A/DConverterreferencevoltageselect
0000:V
DD
0001:V
REFI
0010:V
REFI
×2
0011:V
REFI
×3
0100:V
REFI
×4
1001:Reserved,cannotbeused.
1010:V
BG
×2
1011:V
BG
×3
1100:V
BG
×4
Others:V
DD

WhentheA/Dconverterreferencevoltagesourceisselectedtoderivefromthe
internalV
BG
voltage,thereferencevoltagewhichcomesfromtheexternalVDDor
VREFIpinwillbeautomaticallyswitchedoff.