ST2202A
contrast.ꢀReferꢀtoꢀsectionꢀ16.4.10ꢀforꢀmoreꢀinformation.ꢀ ꢀ
externalꢀDCꢁDCꢀconverter,ꢀwhichꢀgeneratesꢀaꢀhighꢀvoltageꢀ
forꢀdrivingꢀliquidꢀcrystal. outputsꢀ“1”ꢀwhenꢀclearingꢀ
ꢀ
POFF
LPWRꢀ(LCTR),ꢀandꢀoutputsꢀ“0”ꢀbyꢀsettingꢀthisꢀbit,ꢀwhichꢀisꢀ
Besidesꢀcontrastꢀcontrol,ꢀ
ꢀ signalꢀplaysꢀanotherꢀroleꢀ
BLANK
alsoꢀtheꢀdefaultꢀvalue.ꢀ
ꢀ
ofꢀturningꢀdisplayꢀoff.ꢀThisꢀisꢀcontrolledꢀbyꢀregisterꢀbitꢀBLNK
ꢀ
(
LCTR).ꢀSettingꢀBLNKꢀbitꢀwillꢀmakeꢀ ꢀ signalꢀtoꢀ
BLANK
outputꢀ“0”ꢀtoꢀblankꢀtheꢀdisplayꢀregardlessꢀofꢀcontrastꢀcontrol.ꢀ
SettingꢀBLNKꢀbitꢀwillꢀenableꢀtheꢀPWMꢀcontrastꢀcontrolꢀandꢀ
ꢀ
(Contrast control)
BLANK
TheꢀLCDꢀblankꢀsignalꢀisꢀusedꢀtoꢀcontrolꢀtheꢀcontrastꢀofꢀ
displayꢀbyꢀsettingꢀcontrastꢀlevelꢀinꢀLPWM[5:0]ꢀwithꢀ“00000”ꢀ
(default)ꢀrepresentsꢀaꢀmaximumꢀlevelꢀandꢀ“11111”ꢀisꢀforꢀ
ofꢀcourseꢀtheꢀ
ꢀ signal.ꢀIfꢀLPWMTR[5:0]ꢀareꢀallꢀzeros,ꢀ
BLANK
ꢀ signalꢀwillꢀstayꢀatꢀhighꢀlevelꢀwithꢀnoꢀPWMꢀ
BLANK
minimum.ꢀTheꢀ
outputtingꢀaꢀPWMꢀsignalꢀaccordingꢀtoꢀtheꢀsettingsꢀofꢀ
ꢀ signalꢀachievesꢀthisꢀfunctionꢀbyꢀ
BLANK
modulation.
ꢀ
ꢀ
16.2 Mapping the Display Data
TheꢀscreenꢀwidthꢀandꢀheightꢀofꢀtheꢀLCDꢀpanelꢀareꢀ
programmableꢀthroughꢀsoftware.ꢀFIGUREꢀ16ꢁ1ꢀillustratesꢀ
theꢀrelationshipꢀbetweenꢀtheꢀportionꢀofꢀaꢀlargeꢀgraphicsꢀfileꢀ
displayedꢀonꢀtheꢀscreenꢀandꢀtheꢀactualꢀpage.ꢀAlthoughꢀtheꢀ
maximumꢀscreenꢀsizeꢀcanꢀbeꢀupꢀtoꢀ1024x512,ꢀtheꢀactualꢀ
supportedꢀresolutionꢀisꢀlimitedꢀbyꢀtheꢀdisplayꢀbufferꢀsize,ꢀ
ꢀ
whichꢀisꢀalsoꢀtheꢀinternalꢀRAMꢀsize,ꢀ4Kꢀbytes.ꢀEachꢀbitꢀinꢀ
theꢀdisplayꢀmemoryꢀcorrespondsꢀtoꢀaꢀpixelꢀinꢀtheꢀLCDꢀpanel.ꢀ
FIGUREꢀ16ꢁ1ꢀalsoꢀshowsꢀtheꢀmappingꢀofꢀtheꢀdisplayꢀdataꢀ
toꢀtheꢀLCD.ꢀ
ꢀ
FIGURE 16-1 LCD Screen Format
ꢀ
ꢀ
16.3 LCD Interface Timing
TheꢀLCDꢀcontrollerꢀcontinuouslyꢀpumpsꢀtheꢀpixelꢀdataꢀintoꢀ
theꢀLCDꢀpanelꢀviaꢀtheꢀLCDꢀdataꢀbus.ꢀTheꢀbusꢀisꢀtimedꢀbyꢀ
theꢀCP,ꢀLOAD,ꢀandꢀFLMꢀsignals.ꢀTwoꢀkindsꢀofꢀdataꢀwidth,ꢀ1ꢁꢀ
andꢀ4ꢁbit,ꢀareꢀsupportedꢀforꢀmostꢀmonochromeꢀLCDꢀpanels.ꢀ
ReferꢀtoꢀFIGUREꢀ16ꢁ2ꢀforꢀbothꢀ1ꢁꢀandꢀ4ꢁbitꢀinterfaceꢀtiming.ꢀ
ꢀ
Verꢀ2.5ꢀ
42
/75
ꢀ
9/16/2008ꢀ
SITRONIX [ SITRONIX TECHNOLOGY CO., LTD. ]
