单片机原理及应用（双语版·新形态版） 课件 第7章存储器与输入输出（IO）端口的扩展

IntroductoryMicrocontrollerChapter7ExpansionofMemoryandInput/OutputPortsWhydoweneedexpansion?Limitationsofthe8051chipSmallamountofinternalRAM(256bytes)2.LimitedROMprogrammemory3.OnlyfourI/Oports(32lines)DataBus

ControlBus

AddressBusTypesofbusforexpansion8051MemoryorInterface1684P2－high8-bitsP0－low8-bits

P0/RD、/WR、ALE、/PSEN

AddressBus：(16lines)DataBus：(8lines)ControlBus：(4lines)Typesofbusforexpansion40239133843753663573483393210311130122913281427152616251724182319222021P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7P2.7P2.6P2.5P2.4P2.3P2.2P2.1P2.0Vcc+5vP0.0P0.1P0.2P0.3P0.4P0.5P0.6VssGNDXTAL2P3.0/RXDRSTP3.1/TXDP3.2/INT0P3.3/INT1P3.4/T0P3.5/T1P3.6/WRP3.7/RDXTAL1P0.7Vpp/EAPROG/ALEPSENP0P2P3P1Address&databusesDEVICECODEMEMORY8751EPROMSinglechip8951Flash

闪存Singlechip8051ROMSingleChip8031NoMemoryExternalEPROMTheMCS-51Family8751XTAL2XTAL1GND30pF+5V+5VP0P1P3P2/EA8751usingon-chipEPROMEPROMExternalAccessEA=0ExternalprogramEA=1InternalprogramExpansionofProgramMemory7.2.2(Page141)AddingexternalCodeMemorychips64kbyteEPROMChipEnableOutputEnable8031LatchEPROM

27512GND+5VGNDP0P1P3P2/EA/PSENALE8031withexternalROMA15A0D0A7ProgramStoreENable

Codememory

/CE/OEGND8031LatchEPROM

27512GND+5VGNDP0P1P3P2/EA/PSENALE8031withexternalROMA15A0D0A7/CELatch

锁存AddressLatchEnable

地址锁存允许

/OEGNDTheoryoftheLatch(74373)MMMMMMMME11111010TheoryoftheLatch(74373)MMMMMMMM1111101011110101E1TheoryoftheLatch(74373)MMMMMMMM1111101011110101E0TheoryoftheLatch(74373)MMMMMMMM0111000011110101E08031LatchGND+5VGNDP0P1P3P2/EA/PSENALE8031withexternalROMA15A0D0A7EPROM

2751210/CE10/OEGND1567891011121432ADDRESSANDDATAMULTIPLEXINGP0P2AddressA0-A7DataD0-D7AddressA8-A15ALE/PSEN8031LatchGND+5VGNDP0P1P3P2/EA/PSENALE8031withexternalROMA15A0D0A7EPROM

27512/CEAddressesA0–A7AddressesA8–A15DataD0–D7/OEGND8031LatchEPROM

27512GND+5VGNDP0P1P3P2/EA/PSENALE8031withexternalROMA15A0D0A7/CEMOV DPTR,#1000hCLRAMOVC A,@A+DPTR/OEGNDExample7.3.5.1

8kbyteEPROMto8031/PSEN/RD/WR/EAP2P0EPROMD0-D7A0-A7A8-A12/CE8031ALE/OEGND/PSEN/RD/WR/EAP2P0EPROMD0-D7A0-A7A8-A12/CE8031ALE488BusnotationExample7.3.5.1

8kbyteEPROMto8031/OEGND/PSEN/RD/WR/EAP2P0EPROMD0-D7A0-A7A8-A12LATCH/CEGND8031ALE588Example7.3.5.1

8kbyteEPROMto8031/OEGNDExpansionofRAM

7.3(Page144)AddingexternalRAMchips32kbytestaticRAM8751LatchRAM62256GND+5V+5VP0P1P3P2/EA/RD/WRALE8751withexternalRAMA14A0D0A7EPROM/WE/OEA14/WE/OE/CSGND1567891011121432ADDRESSANDDATAMULTIPLEXINGP0P2AddressA0-A7DataD0-D7AddressA8-A15ALE/WR8751LatchGND+5V+5VP0P1P3P2/EA/RD/WRALE8751withexternalRAMA0D0A7AddressesA0–A7EPROM1A14/WE/OERAM622561AddressesA8–A15/CSGND8751LatchGND+5V+5VP0P1P3P2/EA/RD/WRALE8751withexternalRAMA0D0A7EPROM1A14/WE/OERAM622561/CSGND1567891011121432ADDRESSANDDATAMULTIPLEXINGP0P2AddressA0-A7DataD0-D7AddressA8-A15ALE/WR8751GND+5V+5VP0P1P3P2/EA/RD/WRALE8751withexternalRAMA0D0A7EPROMA14/WE/OERAM6225601DataD0–D7/CSGND8751GND+5V+5VP0P1P3P2/EA/RD/WRALE8751withexternalRAMA0D0A7EPROMA14/WE/OERAM6225601DataD0–D7/CSGND8751GND+5V+5VP0P1P3P2/EA/RD/WRALE8751withexternalRAMA0D0A7EPROMA14/WE/OERAM6225600MOV DPTR,#1000hMOVX @DPTR,A/CSGNDExample7.3.5.2:16kbyteRAMto8951/PSEN/RD/WR/EAP2P0RAMD0-D7A0-A7A8-A13/OE/WE8951ALE/CSGND/PSEN/RD/WR/EAP2P0RAMD0-D7A0-A7A8-A13LATCH/OE/WE+5V8951ALE688Example7.3.5.2:16kbyteRAMto8951/CSGNDPleasetry….Question7.5.18 (Page160)Question7.5.182kbyteRAMto8951/PSEN/RD/WR/EAP2P0RAMD0-D7A0-A7A8-A10/OE/WE8951ALE/CSGND/PSEN/RD/WR/EAP2P0RAMD0-D7A0-A7A8-A10LATCH/OE/WE+5V8951ALE388Question7.5.182kbyteRAMto8951/CSGND8031LatchGND+5VGNDP0P1P3P2/EA/RD/WR/PSENALE8031withexternalRAMandROMA15A0D0A7A14A0D0A7RAM62256/WE/OE/CEA14/WE/OEEPROM

27512/OEGND/CSGND8031LatchGND+5VGNDP0P1P3P2/EA/RD/WR/PSENALE8031withexternalRAMandROMA15A0D0A7A0D0A7/OEA14/WE/OERAM62256EPROM

27512MOVC A,@A+DPTR/OEGND/CSGND8031LatchGND+5VGNDP0P1P3P2/EA/RD/WR/PSENALE8031withexternalRAMandROMA15A0D0A7A0D0A7/CEA14/WE/OERAM62256EPROM

27512MOVX @DPTR,A/OEGND/CSGND8031LatchGND+5VGNDP0P1P3P2/EA/RD/WR/PSENALE8031withexternalRAMandROMA15A0D0A7A0D0A7/CEA14/WE/OEEPROM

27512RAM62256MOVX A,@DPTR/OEGND/CSGNDExample7.3.5.3:8kBRAM,16kBEPROM/PSEN/RD/WR/EAP2P0EPROMRAMD0-D7A0-A7A8-A12D0-D7A0-A7A8-A13/OE/OE/WE8031ALE/CE/CS/PSEN/RD/WR/EAP2P0EPROMRAMD0-D7A0-A7A8-A12D0-D7A0-A7A8-A13LATCH/OE/OE/WEGND8031ALE6658888Example7.3.5.3:8kBRAM,16kBEPROM/CE/CSGNDPleasetry….Question7.5.20 (Page160)Question7.5.2016kBEPROM4kBRAM/PSEN/RD/WR/EAP2P0EPROMRAMD0-D7A0-A7A8-A11D0-D7A0-A7A8-A13/OE/OE/WE8031ALE/CE/CSGND/PSEN/RD/WR/EAP2P0EPROMRAMD0-D7A0-A7A8-A11D0-D7A0-A7A8-A13LATCH/OE/OE/WEGND8031ALE6648888Question7.5.2016kBEPROM4kBRAM/CE/CSGNDExpansionofParallelPorts7.4(Page150)IncreasingthenumberofI/Olinesonthe8051Limitationsofthe8051chip1.SmallamountofinternalRAM(256bytes)2.LimitedROMprogrammemory3.OnlyfourI/Oports4.WithexternalmemoryonlytwoI/OportsProgrammablePeripheralInterface(PPI)可编程外围接口ToincreasethenumberofI/Olines8255APPI8lines24linesPortCPortBPortAProgrammablePeripheralInterface(PPI)可编程外围接口8255APPI8051WriteOutputPortCPortBPortAProgrammablePeripheralInterface(PPI)可编程外围接口8255APPI8051ReadInput/RD/WRRESET/CSA0A1DatabusD0-D7PA0-PA7PC4-PC7PC0-PC3PB0-PB78255AGrpAcontrolGrpBcontrolGrpAPortAGrpAPortCGrpBPortCGrpBPortBLOGICBufferPortAPortBPortCControlDataAddressPortsPortsPortsPortsPortCPortBPortAA1A0Addressingpinson8255AControlPortCPortBPortAPortCPortBPortAA1A0ControlPortCPortBPortA100000011110010Addressingpinson8255A/RD/WRRESET/CSA0A1DatabusD0-D7PA0-PA7PC4-PC7PC0-PC3PB0-PB78255AGrpAcontrolGrpBcontrolGrpAPortAGrpAPortCGrpBPortCGrpBPortBLOGICBufferPortAPortBPortCControl01Write/RD/WRRESET/CSA0A1DatabusD0-D7PA0-PA7PC4-PC7PC0-PC3PB0-PB78255AGrpAcontrolGrpBcontrolGrpAPortAGrpAPortCGrpBPortCGrpBPortBLOGICBufferPortAPortBPortCControl00Read/RD/WRRESET/CSA0A1DatabusD0-D7PA0-PA7PC4-PC7PC0-PC3PB0-PB78255AGrpAcontrolGrpBcontrolGrpAPortAGrpAPortCGrpBPortCGrpBPortBLOGICBufferPortAPortBPortCControl10Write000011/RD000100/WR111000/CS01

0

0WritetoControlRegister

1WritethroughPortA

0Operation

A010

01

0

0

A1111100XXXXReadthroughPortAReadthroughPortBReadthroughPortCWritethroughPortBWritethroughPortCDatabusinhigh-ZmodeControlLinesonthe8255ATable7.6000011/RD000100/WR111000/CS01

0

0WritetoControlRegister

1WritethroughPortA

0Operation

A010

01

0

0

A1111100XXXXReadthroughPortAReadthroughPortBReadthroughPortCWritethroughPortBWritethroughPortCDatabusinhigh-ZmodeControlLinesonthe8255ATable7.1/RD/WRRESET/CSA0A1DatabusD0-D7PA0-PA7PC4-PC7PC0-PC3PB0-PB78255AGrpAcontrolGrpBcontrolGrpAPortAGrpAPortCGrpBPortCGrpBPortBLOGICBufferPortAPortBPortCControlI/OGroupAGroupAPortAPortChiGroupBPortBPortClowPortClownibbledirectionThe8255AControlRegisterPortBdirectionGroupBmodePortChighnibbledirectionPortAdirectionGroupAmodeGroupAmodePortcontrol10000=Output1=Input/RD/WRLatch8255PortAPortBPortCConnectionof8051to8255A8051ALEAddressbusDatabusThe8255AisMemoryMapped存储器交换/CS/RD/WRLatch8255P2.0PortAPortBPortCConnectionof8051to8255AP0.7P0.0A0A1PortA= XXXXXXX0XXXXXX00PortB= XXXXXXX0XXXXXX01PortC= XXXXXXX0XXXXXX10Control= XXXXXXX0XXXXXX11MOV DPTR,#0001hMOV A,#55hMOVX @DPTR,A558051ALEPortA= XXXXX000XXXXXXXXPortB= XXXXX001XXXXXXXXPortC= XXXXX010XXXXXXXXControl= XXXXX011XXXXXXXXConnectionof8051to8255A/CS/RD/WR8255P2.0PortAPortBPortCP0.7P0.0A0A1P2.1P2.2MOV DPTR,#0200hMOV A,#77hMOVX @DPTR,A778051Pleasetry….Question7.5.31 (Page161)Question7.5.31Registers:0800h-0803h A&Binputs;CoutputPortA =0800hPortB =0801hPortC =0802hControl=0803hUseSection7.4.3ControlRegisterBit4:PortAdirectionBit1:PortBdirectionBit0:PortC(hi)directionBit3:PortC(lo)direction0=Output1=Input1001MOV DPTR,#0803hMOV A,#10010010bMOVX @DPTR,A/CS/RD/WRLatch82558051P2.0PortAPortBPortCConnectionof8051to8255AP0.7P0.0A0A1PortA= XXXXXXX0XXXXXX00PortB= XXXXXXX0XXXXXX01PortC= XXXXXXX0XXXXXX10Control= XXXXXXX0XXXXXX11MOV DPTR,#0001hMOV A,#55hMOVX @DPT