SCCtlSignals.tioga
Pradeep Sindhu April 8, 1987 3:57:08 pm PDT
Signal naming conventions
There are a number of prefixes that have well-defined meanings:
PCtl control signal generated by PmCode
BCtl control signal generated by BmCode
x control signal obtained by resolving a conflict between a PSide signal and a BSide signal
n low true signal
BCyclePipe0
Signal Name Meaning
BCycle0 Indicates that header cycle is sitting at output of BCyclePipe0
BCmd0 DynaBus command at output of BCyclePipe0
BFault0 DynaBus fault bit at output of BCyclePipe0
BDataInFCBits0 DynaBus FaultCode bits at output of BCyclePipe0
BDataIn3LSB0 3 LSB of BCyclePipe0
BCyclePipe2
Signal Name Meaning
RplyShared2 RplyShared bit at output of BCyclePipe2
BCmd2 DynaBus command at output of BCyclePipe2
BFault0 DynaBus fault bit at output of BCyclePipe0
BInterfaceInCtl
Signal Name Meaning
FBTIP FlushBlock Transaction In Progress
NonFBTIP Non FlushBlock Transaction In Progress
BCycle1 BCycle0 delayed one clock
BCycle2 BCycle1 delayed one clock
BCycle3 BCycle2 delayed one clock
BCycle4 BCycle3 delayed one clock
BCycle5 BCycle4 delayed one clock
BCycle6 BCycle5 delayed one clock
MyBFault Reply packet for cache has fault bit set
MyBFaultCode Fault code from reply packet
BLdPRdLatch Loads PRdLatch
SelMSW Select MostSignificant/LeastSignificant word of incoming cycle
EnBWdWtPipe Enables first stage of BWdWtPipe; rest are derived from this
DeMapRply1 It is Cycle 1 of a DeMapRply
ClrVPV Clears VPValid bit
B
mCode
Signal Name Meaning
BCtlSelWSData Selects WSData/WdWtData to write to Ram
BCtlRamForBCWS Reserves Ram for write part of CWS (asserted only
if the CWSRply matches)
BCtlSelBCWS Selects WSData as input to CWS comparator
BCtlWtRam Drive Block Assembly register/word contents onto bit lines
BCtlRdRam Load Ram Read latches
BCtlEnRamSel Enable Ram select line
BCtlSelWdData Select Word/Block data to be written to the Ram
BCtlLdFIFO Load FIFO with contents of RamRdLatch
BCtlSelRRdLatch Used to compute select for WdWtDataMux
Global Signals
Signal Name Meaning
Reset Reset chip
Clock DynaBus clock
nClock inverse of DynaBus clock
IdMatcher
Signal Name Meaning
IdMatch0 Indicates whether incoming packet's Id=MyId
IOSection
Signal Name Meaning
SetReschedule Generates reschedule signal for processor
PInterface
Signal Name Meaning
CWSEq Indicates that the two inputs to the CWS comparator are equal
PCmd Processor command
PByteSel Processor Byte Select
PAdrs->PAdrs3LSB Low 3 bits of processor address
PInterfaceCtl
Signal Name Meaning
PCycle0 Indicates cycle0 of processor access
PCycle1 Indicates cycle1 of processor access
PCycle2 Indicates cycle2 of processor access
DrPBus Drives cache data onto PBus
LdPRdLatch Loads PRdLatch latch
DrPAdrs Drives PAdrs onto ABus
LdPAdrs Loads PAdrs latch
LdPWtLatch Loads PWtLatch latch
*PReject PBus Reject signal
*PFault PBus Fault signal
*PReschedule PBus Reschedule signal
xSelRRdLatch Selects RRdLatch/PWtLatch as source for WdWtDataMux
P
mCode (Outputs)
Signal Name Meaning
PCtlFault Cache detected fault
PCtlSelBFC Selects BFaultCode/CacheFaultCode for processor
PCtlSelRRdLatch Selects RRdLatch/PWtLatch for BufData
PCtlSelRplyData Selects RplyData/WdRdData for PRdLatch
PCtlLdSnooper Loads address register in Snooper
PCtlWtMchVCam Loads VCamWtReg and drives it onto bitlines
PCtlPartVMch Make the match (if any) be a partial one
PCtlRdVCam Loads VCamRdLatch with value on bitlines
PCtlABusCmd Selects source to drive onto ABus
PCtlFrzVictim Prevent victim pointer from moving
PCtlShftVictim Move victim to next line (only if not frozen)
PCtlLdUse Enable loading of use bit from VMatch
PCtlSetFBTIP Sets FBTIP state bit
PCtlSetNonFBTIP Sets NonFBTIP state bit
PCtlReleaseP Signals that it is ok for processor to proceed
PCtlWtRam Write Ram
PCtlRdRam Read Ram
PCtlEnRamSel Enable Ram select line
PCtlRSCmd Selects 0|LRM|LVM|Victim as output of RSMux
PCtlSetSnooperValid Sets valid bit in Snooper
PCtlRdRCam Loads RCam read latch
PCtlWtMchRCam Loads RCamWtReg and drives it onto bitlines
PCtlEnCamSel Enables Cam select line
PCtlEnCamSelExt Connects CamSelectLineExt to CamSelectLine
PCtlCSCmd Selects 0|LRM|LVM|Victim as output of CSMux
PCtlBusy Indicates PCtl is busy
PCtlLdRBufDataMSW Loads most significant word of request buffer data
PCtlLdRBufDataLSW Loads least significant word of request buffer data
PCtlLdRBufHd Loads header part of request buffer data
PCtlLdFIFO Loads FIFO from output of Ram
P
mCode (Inputs)
Signal Name Meaning
PCmd Processor Command (3 bits only)
AVM ArrayVirtualMatch
FBTIP FlushBlock in progress
FBTIP Non FlushBlock in progress
RamForP PSide can use Ram
RamInterlockCtl
Signal Name Meaning
RamForP Indicates its ok for processor to use Ram
EarlyRamForP Indicates its ok for processor to use Ram (one cycle before RamForP)
PWtInProg Indicates processor write is in progress
xWtRam Drives selected bits of data onto bitlines
xRdRam Loads RamRdLatch
xEnRamSel Enables Ram Select Line
xByteSel Selects one or more bytes (in a word) to be written
xWdAdrs Low 3 bits of address (thus address of word in block)
xSelWdData Selects word data path for reading/writing Ram
xRSCmd Selects 0|LRM|LVM|Victim as output of RSMux
RamInterface
Signal Name Meaning
LdRRdLatch Load Ram RdLatch
RCam
Signal Name Meaning
ARM Indicates at least one line in the real cam matched
RCamInterlockCtl
Signal Name Meaning
RdRCam Loads RCamRdLatch with value on bitlines
WtMchRCam Loads RCamWtReg and drives it onto bitlines
EnCamSel Enables Cam Select Line
*EnCamSelExt Connects CamSelectLineExt to CamSelectLine
*PartRMch Make the match (if any) be a partial one
CSCmd Selects 0|LRM|LVM|Victim as output of CSMux
Snooper
Signal Name Meaning
SnooperMatch2 Match signal from Snooper
SnooperCtl
Signal Name Meaning
BOwner Pulls DynaBus owner line
BShared Pulls DynaBus shared line
SetSh Sets shared bit for selected line
ClrSh Clears shared bit for selected line
RplyStale Indicates that RBRply packet is stale
SharedOwner
Signal Name Meaning
AOw Array Owner bit
ASh Array Shared bit
VCam
Signal Name Meaning
AVM Indicates at least one line in the virtual cam matched
Victim
Signal Name Meaning
nCIn ~CarryIn signal for victim
nCOut ~CarryOut signal for victim