Filter
Top Products
www.ti.com
3.2EMACControlModuleInterruptTimerCountRegister(EWINTTCNT)
EMACControlModuleRegisters
TheEMACcontrolmoduleinterrupttimercountregister(EWINTTCNT)isusedtocontrolthegeneration
ofback-to-backinterruptsfromtheEMACandMDIOmodules.Thevalueofthistimercountisloaded
intoaninternalcountereverytimeinterruptsareenabledusingtheINTENbitintheEMACcontrol
moduleinterruptcontrolregister(EWCTL).Asecondinterruptcannotbegenerateduntilthiscount
reaches0.ThecounterisdecrementedatafrequencyofPLL1clock/6;thedefaultresetcountis0
(inactive)andthemaximumvalueis1FFFFh(131071).
TheEWINTTCNTisshowninFigure12anddescribedinTable9.
Figure12.EMACControlModuleInterruptTimerCountRegister(EWINTTCNT)
311716
ReservedEWINTTCNT
R-0R/W-0
150
EWINTTCNT
R/W-0
LEGEND:R=Readonly;R/W=Read/Write;-n=valueafterreset
Table9.EMACControlModuleInterruptTimerCountRegister(EWINTTCNT)FieldDescriptions
BitFieldValueDescription
31-18Reserved0Reserved
17-0EWINTTCNT0-1FFFFhInterrupttimercount.EWINTTCNTisa17-bitinterrupttimercountthatisusedtocontrolthe
generationofback-to-backinterruptsfromtheEMACandMDIOmodules.Thevalueof
EWINTTCNTisloadedinaninternaltimecountereverytimeinterruptsareenabledby
writinga1totheINTENbitinEWCTL(notetheINTENbitmusttransitionfrom0to1to
initializetheinternaltimecounter).Onceinitialized,thetimecounterwillcountdownwith
eachperipheralclockuntilitreaches0.Asecondinterruptcannotbegenerateduntilthis
counterreaches0.Anytimethetimecounterhasanon-zerovalue,theinterruptlogicwill
blocktheEMAC_MDIO_INTinterrupttotheCPU.Thus,ifanyoftheinterruptscomingtothe
EMACcontrolmoduleisasserted,theinterruptlogicwillasserttheEMAC_MDIO_INTsignal
totheCPU,providedtheINTENbitinEWCTLisset,andthetimecountervalueis0.
54EthernetMediaAccessController(EMAC)/SPRU941A–April2007
ManagementDataInput/Output(MDIO)
SubmitDocumentationFeedback