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softwarecontrol(pcm1780/82)
RegisterWriteOperation
MSB
0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 D7 D6 D5 D4 D3 D2 D1 D000
LSB
寄存器 index (或者地址) 寄存器 数据
r0001-01
IDX0
D7 D6 D4D5 D3 D2 D1 D00
MS
MC
MD X 0
IDX6
X
IDX1IDX2IDX3IDX4IDX5IDX6
X
t0048-01
ControlInterfaceTimingRequirements
pcm1780,pcm1781,pcm1782
SLES132A–MARCH2005–REVISEDAPRIL2005
thepcm1780/82hasmanyprogrammablefunctionsthatcanbecontrolledinthesoftwarecontrolmode;这
functionsarecontrolledbyprogrammingtheinternalregistersusingms,mc,andmd.
theserialcontrolinterfaceisa3-wireserialportwhichoperatesasynchronouslytotheaudioserialinterface.
theserialcontrolinterfaceisusedtoprogramtheon-chipmoderegisters.thecontrolinterfaceincludesmd
(pin4),mc(pin3),andms(pin2).mdistheserialdatainput,usedtoprogramthemoderegisters.mcisthe
serialbitclock,usedtoshiftdataintothecontrolport.msistheselectinput,usedtoenablethemodecontrol
端口.
allwriteoperationsfortheserialcontrolportuse16-bitdatawords.figure24showsthecontroldataword
format.themostsignificantbitmustbea0.sevenbits,labeledidx[6:0],settheregisterindex(oraddress)为
thewriteoperation.theleastsignificanteightbits,d[7:0],containthedatatobewrittentotheregisterspecified
byidx[6:0].
figure25showsthefunctionaltimingdiagramforwritingtotheserialcontrolport.msisheldatalogic-1state
untilaregisterneedstobewritten.tostarttheregisterwritecycle,msissettologic0.sixteenclocksarethen
providedonmc,correspondingtothe16bitsofthecontroldatawordonmd.afterthesixteenthclockcyclehas
完成,msissettologic1tolatchthedataintotheindexedmodecontrolregister.
figure24.controldatawordformatformd
figure25.registerwriteoperation
figure26showsadetailedtimingdiagramfortheserialcontrolinterface.thesetimingparametersarecriticalfor
propercontrolportoperation.
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