IFUPLAMainPipeControlImpl.mesa
Copyright c 1984 by Xerox Corporation. All rights reserved.
Last edited by McCreight, June 6, 1986 5:43:46 pm PDT
Last edited by Curry, September 14, 1986 4:15:52 pm PDT
Don Curry March 9, 1987 5:06:25 pm PST
DIRECTORY
Commander, IFUPLAMainPipeControl, IO, PLAOps, Rope;
IFUPLAMainPipeControlImpl: CEDAR PROGRAM
IMPORTS Commander, IO, PLAOps, Rope =
BEGIN OPEN PO: PLAOps;
MainPipeControlIn:  TYPE = IFUPLAMainPipeControl.MainPipeControlIn;
MainPipeControlOut: TYPE = IFUPLAMainPipeControl.MainPipeControlOut;
CondEffect:    TYPE = IFUPLAMainPipeControl.CondEffect;
MainPipeControlPLA: PO.PLA;
MainPipeControlProc: PROC[argRec: MainPipeControlIn] RETURNS [resRec: MainPipeControlOut] = {
arg: REF MainPipeControlIn  ← NARROW[MainPipeControlPLA.data];
res: REF MainPipeControlOut ← NARROW[MainPipeControlPLA.out];
arg^ ← argRec; PO.GetOutForData[MainPipeControlPLA]; resRec ← res^};
condEffectIsSig: CondEffect ← LAST [CondEffect];
forceBubble:  MainPipeControlOut =
[microExcptJmp: bubble, except: [specialCode, bubble]];
GenPhBOutputs: PROC = {
maskableTrap: PO.BoolExpr ←
PO.And[
BETrue[[trapsEnabled2:  TRUE]],
PO.Or[
BETrue[[eStkOverflow2:  TRUE]],
PO.And[
BETrue[[instStarting2:  TRUE]],
BETrue[[rschWaitingIn: TRUE]] ],
PO.And[
BETrue[[push2:    TRUE]],
BETrue[[iStkNearlyFull: TRUE]] ] ] ];
stage2Failed: PO.BoolExpr ← PO.Or[
BETrue[[reset:     TRUE]],
BETrue[[stage2BAbort:  TRUE]],
PO.And[
BETrue[[eUCondition2: TRUE]],
BE[m:[condEffect2: condEffectIsSig], d:[condEffect2: macroTrap]] ],
maskableTrap ];
stage2FailedOr1Hold: PO.BoolExpr ← PO.Or[
stage2Failed,
BETrue[[stage1BHold: TRUE]] ];
loadStage1: PO.BoolExpr ← PO.Or[
BEFalse[[microExcptJmpBubble: TRUE]], BETrue[[reset: TRUE]] ];
loadStages23: PO.BoolExpr ←
PO.Or[ BEFalse[[dPReject:   TRUE]], BETrue[[reset: TRUE]] ];
Set[ s: stage2Failed,    out: [stage3A: abort  ] ];
Set[ s: stage2FailedOr1Hold, out: [stage2A: bubble ] ];
Set[ s: loadStage1,    out: [loadStage1: TRUE  ] ];
Set[ s: loadStages23,    out: [loadStage2: TRUE  ] ];
Set[ s: loadStages23,    out: [loadStage3: TRUE  ] ]};
Set[ s: BETrue[[x2ASrcLit1: TRUE]], out: [x2ASrcLit2: TRUE  ] ]};
GenPhAOutputs: PROC = {
cur, temp: PO.BoolExpr;
rschClear is generated below and fed back in the same phase A (since it would be expensive to invert its generating condition). It is just used to compute the newRschWaiting.
rschWaitingIn: PO.BoolExpr ← BETrue[[rschWaitingIn: TRUE]];
newRschWaiting: PO.BoolExpr ← PO.And[
BEFalse[[reset: TRUE]],
BEFalse[[rschClearIn: TRUE]],
PO.Or[ rschWaitingIn, BETrue[[reschedule: TRUE]] ] ];
notCondEffect1Bubble : PO.BoolExpr ←
PO.Or[
BETrue[[reset: TRUE]],
PO.Not[BE[m: [condEffect1: condEffectIsSig], d: [condEffect1: bubble]]] ];
stage1BHolding: PO.BoolExpr ← PO.Or[
BETrue[[reset:    TRUE]],
PO.And[
notCondEffect1Bubble,
PO.Or[ BETrue[[stage1BHold:  TRUE]], BETrue[[dPReject: TRUE]] ] ] ];
stage1BHolding: PO.BoolExpr ← PO.And[
BEFalse[[reset: TRUE]],
notCondEffect1Bubble,
PO.Or[ BETrue[[stage1BHold:  TRUE]], BETrue[[dPReject: TRUE]] ] ];
eUStkOverflow:  PO.BoolExpr ← PO.And[
BETrue[[trapsEnabled2:  TRUE]],
BETrue[[eStkOverflow2: TRUE]] ];
ifuStkOverflow:  PO.BoolExpr ← PO.And[
BETrue[[trapsEnabled2: TRUE]],
BETrue[[iStkNearlyFull: TRUE]],
PO.Or[
BETrue[[dPFaulting: TRUE]],
PO.And[
BEFalse[[dPReject: TRUE]],
PO.Or[
BETrue[[push2: TRUE]],
BETrue[[eStkOverflow2: TRUE]],
BETrue[[instFault2: TRUE]],
PO.And[BETrue[[instStarting2: TRUE]], rschWaitingIn],
PO.And[
BETrue[[eUCondition2: TRUE]],
BE[ m: [condEffect2: condEffectIsSig], d: [condEffect2: macroTrap] ] ] ] ] ] ];
interlock: PO.BoolExpr ← PO.And[
PO.Or[
BETrue[[stage1BHold: TRUE]],
PO.And[
BETrue[[stage1HoldIfReject: TRUE]],
BETrue[[dPReject: TRUE]] ] ],
notCondEffect1Bubble ];
interlock: PO.BoolExpr ← PO.And[
PO.Or[
BETrue[[stage1BHold: TRUE]],
BETrue[[dPReject: TRUE]] ],
notCondEffect1Bubble ];
Set[ s: newRschWaiting, out:[ rschWaiting: TRUE ] ];
Set[ s: BETrue[[dPFaulting: TRUE]], out:[ stage3BCPipe: abort ] ];
Set[ s: stage1BHolding, out:[
stage1BHolding:  TRUE,
notBcLoadStage1: TRUE ] ];
Reset
Set[s: BETrue[[reset: TRUE]], out:[
stage2B:   abort,
microExcptJmp: resetting,
except:   [specialCode, reset] ] ];
cur ← BEFalse[[reset: TRUE]];
Intermediate cycle of protected microinstruction sequence
Set[s: PO.And[cur, BETrue[[protMicroCycle: TRUE]]], out:[
microExcptJmp: none,
except:   [specialCode, none] ] ];
cur ← PO.And[cur, BEFalse[[protMicroCycle: TRUE]]];
IFU stack overflow
Set[s: PO.And[cur, ifuStkOverflow], out:[
stage2B:   abort,
microExcptJmp: trap,
except:   [specialCode, iStkOFlow] ] ];
cur ← PO.And[cur, PO.Not[ifuStkOverflow]];
Data PBus Fault, pipe stage 3
Set[s: PO.And[cur, BETrue[[dPFaulting: TRUE]]], out:[
stage2B:   abort,
microExcptJmp: trap,
except:   [dpFault] ] ];
cur ← PO.And[cur, BEFalse[[dPFaulting: TRUE]]];
Reject
Set[s: PO.And[cur, BETrue[[dPReject: TRUE]], notCondEffect1Bubble], out: forceBubble ];
cur ← PO.And[cur, BEFalse[[dPReject: TRUE]]];
ALU Condition, pipe stage 2
temp ← PO.And[cur, BETrue[[eUCondition2: TRUE]]];
Set[s:temp, m:[condEffect2: condEffectIsSig], d:[condEffect2: macroTrap], out:[
stage2B:   abort,
microExcptJmp: trap,
except:   [condCode] ] ];
Set[s:temp, m:[condEffect2: condEffectIsSig], d:[condEffect2: macroJump], out:[
stage2B:   abort,
microExcptJmp: cJump,
except:   [specialCode, cJump] ] ];
Set[s:temp, m:[condEffect2: condEffectIsSig], d:[condEffect2: microJump], out:[
microExcptJmp: microJump ] ];
cur ← PO.And[cur, BEFalse[[eUCondition2: TRUE]]];
EU stack overflow, pipe stage 2
Set[s: PO.And[cur, eUStkOverflow], out:[
stage2B:   abort,
microExcptJmp: trap,
except:   [specialCode, eStkOFlow] ] ];
cur ← PO.And[cur, PO.Not[eUStkOverflow]];
Pipe Interlock
Set[s: PO.And[cur, interlock], out: forceBubble ];
cur ← PO.And[cur, PO.Not[interlock]];
cur ← PO.And[cur, BETrue[[instStarting2: TRUE]] ];
Reschedule Waiting, pipe stage 2
Set[s: PO.And[cur, BETrue[[trapsEnabled2: TRUE]], rschWaitingIn], out:[
rschClear:  TRUE,
stage2B:   abort,
microExcptJmp: trap,
except:   [specialCode, rschlWait] ]];
cur ← PO.And[cur, PO.Or[PO.Not[rschWaitingIn], BEFalse[[trapsEnabled2: TRUE]]]];
Instruction Fetch Fault, pipe stage 2
Set[s:cur, m:[instFault2: TRUE], d:[instFault2: TRUE], out:[
stage2B:   abort,
microExcptJmp: trap,
except:   [specialCode, ipFault] ]];
cur ← PO.And[cur, BEFalse[[instFault2: TRUE]]];
ELSE new unexceptional microinstruction [ ]
};
BE: PROC [m, d: MainPipeControlIn ] RETURNS[ PO.BoolExpr ] = {
mRef:  REF MainPipeControlIn ← NARROW[MainPipeControlPLA.mask];
dRef:  REF MainPipeControlIn ← NARROW[MainPipeControlPLA.data];
mRef^ ← m; dRef^ ← d; RETURN[PO.GetBEForDataMask[MainPipeControlPLA]]};
BETrue: PROC [ d: MainPipeControlIn ] RETURNS[ PO.BoolExpr ] = { RETURN[ BE[d,d] ] };
BEFalse: PROC [ d: MainPipeControlIn ] RETURNS[ PO.BoolExpr ] = { RETURN[ BE[d,[]] ] };
Set: PROC [s: PO.BoolExpr ← NIL, m, d: MainPipeControlIn ← [ ], out: MainPipeControlOut] = {
res: REF MainPipeControlOut ← NARROW[MainPipeControlPLA.out];
s ← IF s=NIL THEN BE[m,d] ELSE PO.And[s, BE[m,d] ];
res^ ← out; PO.SetOutForBE[MainPipeControlPLA, s]};
GenMainPipeControl: Commander.CommandProc = {
MainPipeControlPLA ← PO.NewPLA[
name.Cat[".MainPipeControlIn"],
name.Cat[".MainPipeControlOut"],
name ];
GenPhBOutputs[];
GenPhAOutputs[];
[ ] ← PO.ConvertTermListToCompleteSum[MainPipeControlPLA.termList, FALSE, FALSE, cmd.out];
[ ] ← PO.FindAMinimalCover[MainPipeControlPLA.termList, 120, cmd.out];
PO.WritePLAFile[MainPipeControlPLA, NIL, cmd.out] };
ReadMainPipeControl: Commander.CommandProc =
{MainPipeControlPLA ← PO.ReadPLAFile[name, cmd.out]};
name:  IO.ROPE = "IFUPLAMainPipeControl";
Commander.Register[key:"GenMainPipeControl",  proc: GenMainPipeControl];
Commander.Register[key:"ReadMainPipeControl", proc: ReadMainPipeControl];
END.