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3.6.3busholders
3.7paralleli/oports
3.7.1enhanced8-/16-bithost-portinterface(hpi8/16)
TMS320VC5409A
fixed-pointdigitalsignalprocessor
SPRS140F–NOVEMBER2000–REVISEDJANUARY2005
the5409ahastwobusholdercontrolbits,bh(bscr[1])andhbh(bscr[2]),tocontrolthebuskeepers
oftheaddressbus(a[15-0]),databus(d[15-0]),andthehpidatabus(hd[7-0]).buskeeper
enabling/disablingisdescribedintable3-5.
table3-6.busholdercontrolbits
hpi16pinbhhbhd[15-0]a[15-0]hd[7-0]
000OFFOFFOFF
001OFFOFFON
010ONOFFOFF
011ONOFFON
100OFFOFFON
101OFFONON
110ONOFFON
111ONONON
the5409ahasatotalof64ki/oports.theseportscanbeaddressedbytheportrinstructionorthe
portwinstruction.theissignalindicatesaread/writeoperationthroughani/oport.the5409acan
interfaceeasilywithexternaldevicesthroughthei/oportswhilerequiringminimaloff-chipad-
dress-decodingcircuits.
the5409ahost-portinterface,alsoreferredtoasthehpi8/16,isanenhancedversionofthestandard
8-bithpifoundonearliertms320c54x™dsps(542,545,548,and549).the5409ahpicanbeusedto
interfacetoan8-bitor16-bithost.whentheaddressanddatabusesforexternali/oisnotused(至
interfacetoexternaldevicesinprogram/数据/iospaces),the5409ahpicanbeconfiguredasanhpi16to
interfacetoa16-bithost.thisconfigurationcanbeaccomplishedbyconnectingthehpi16pintologic"1".
whenthehpi16pinisconnectedtoalogic"0",the5409ahpiisconfiguredasanhpi8.thehpi8isan
8-bitparallelportforinterprocessorcommunication.thefeaturesofthehpi8include:
standardfeatures:
•
sequentialtransfers(withautoincrement)orrandom-accesstransfers
•
HostinterruptandC54x™interruptcapability
•
Multipledatastrobesandcontrolpinsforinterfaceflexibility
thehpi8interfaceconsistsofan8-bitbidirectionaldatabusandvariouscontrolsignals.十六-位
transfersareaccomplishedintwopartswiththehbilinputdesignatinghighorlowbyte.thehost
communicateswiththehpi8throughthreededicatedregisters—thehpiaddressregister(hpia),这
hpidataregister(hpid),andthehpicontrolregister(hpic).thehpiaandhpidregistersareonly
accessiblebythehost,andthehpicregisterisaccessiblebyboththehostandthe5409a.
enhancedfeatures:
•
accesstoentireon-chipramthroughdmabus
•
Capabilitytocontinuetransferringduringemulationstop
FunctionalOverview
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