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3.7.2hpinonmultiplexedmode
hpid[15:0]
有
HDS1, hds2, hcs
DMA
内部的
记忆
ppd[15:0]
data[15:0]
address[15:0]
r/w
数据 strobes
准备好
HPI16
HRDY
54xx
CPU
V
CC
HCNTL0
HCNTL1
hr/w
HINT
HBIL
HOST
TMS320VC5409A
fixed-pointdigitalsignalprocessor
SPRS140F–NOVEMBER2000–REVISEDJANUARY2005
thehpi16isanenhanced16-bitversionofthetms320c54x™dsp8-bithost-portinterface(hpi8).这
hpi16isdesignedtoallowa16-bithosttoaccessthedspon-chipmemory,withthehostactingasthe
masteroftheinterface.someofthefeaturesofthehpi16include:
•
16-bitbidirectionaldatabus
•
Multipledatastrobesandcontrolsignalstoallowgluelessinterfacingtoavarietyofhosts
•
onlynonmultiplexedaddress/datamodesaresupported
•
16-bitaddressbususedinnonmultiplexedmodetoallowaccesstoallinternalmemory(包含
internalextendedaddresspages)
•
HRDYsignaltoholdoffhostaccessesduetoDMAlatency
•
thehpi16actsasaslavetoa16-bithostprocessorandallowsaccesstotheon-chipmemoryofthe
dsp.
便条
Onlythenonmultiplexedmodeissupportedwhenthe5409AHPIisconfiguredasa
hpi16(seefigure3-8).
the5409ahpifunctionsasaslaveandenablesthehostprocessortoaccesstheon-chipmemory.一个
majorenhancementtothe5409AHPIoverpreviousversionsisthatitallowshostaccesstotheentire
在-chipmemoryrangeofthedsp.thehostandthedspbothhaveaccesstotheon-chipramatall
timesandhostaccessesarealwayssynchronizedtothedspclock.ifthehostandthedspcontendfor
accesstothesamelocation,thehosthaspriority,andthedspwaitsforonecycle.notethatsincehost
accessesarealwayssynchronizedtothe5409aclock,anactiveinputclock(clkin)isrequiredforhpi
accessesduringidlestates,andhostaccessesarenotallowedwhilethe5409aresetpinisasserted.
在
nonmultiplexed
模式,ahostwithseparateaddress/databusescanaccessthehpi16dataregister
(hpid)viathehd16-bitbidirectionaldatabus,andtheaddressregister(hpia)viathe16-bithaaddress
总线.thehostinitiatestheaccesswiththestrobesignals(hds1,hds2,hcs)andcontrolsthedirectionof
theaccesswiththehr/wsignal.thehpi16canstallhostaccessesviathehrdysignal.notethatthe
HPICregisterisnotavailablein
nonmultiplexed
modesincetherearenohcntlsignalsavailable.所有
hostaccessesinitiateadmareadorwriteaccess.figure3-8showsablockdiagramofthehpi16in
nonmultiplexed
模式.
figure3-8.host-portinterface—nonmultiplexedmode
26
FunctionalOverview
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