try to fix reti

cpu.go

@@ -14,7 +14,7 @@ func NewCPU(core MemIoRW) *CPU {
 	z := CPU{}
 	z.Reset()
 	z.core = core
-	z.cycleCount = 0
+	z.TStates = 0
 	z.codeCoverageEnabled = false
 	// z.memAccess =
 	z.codeCoverageEnabled = false
@@ -31,7 +31,7 @@ func (z *CPU) RunInstruction() (uint32, *map[uint16]byte) {
 	if z.codeCoverageEnabled {
 		z.codeCoverage[z.PC] = true
 	}
-	pre := z.cycleCount
+	pre := z.TStates
 	if z.Halted {
 		z.execOpcode(0x00)
 	} else {
@@ -39,7 +39,7 @@ func (z *CPU) RunInstruction() (uint32, *map[uint16]byte) {
 		z.execOpcode(opcode)
 	}
 	z.processInterrupts()
-	return z.cycleCount - pre, &z.memAccess
+	return z.TStates - pre, &z.memAccess
 }
 
 // SetState set current CPU state
@@ -71,14 +71,18 @@ func (z *CPU) SetState(state *CPU) {
 	z.Flags = state.Flags
 	z.FlagsAlt = state.FlagsAlt
 
+	z.TStates = state.TStates
+	z.TStatesPart = state.TStatesPart
 	z.MemPtr = state.MemPtr
 	z.IMode = state.IMode
 	z.Iff1 = state.Iff1
 	z.Iff2 = state.Iff2
 	z.Halted = state.Halted
-	z.IntOccurred = state.IntOccurred
-	z.NmiOccurred = false
+	z.intData = state.intData
+	z.intPending = state.intPending
+	z.nmiPending = state.nmiPending
 }
+
 func (z *CPU) GetState() *CPU {
 	return &CPU{
 		A:    z.A,
@@ -109,17 +113,16 @@ func (z *CPU) GetState() *CPU {
 		Iff1:        z.Iff1,
 		Iff2:        z.Iff2,
 		Halted:      z.Halted,
-		CycleCount:  z.cycleCount,
-		IntOccurred: z.IntOccurred,
-		NmiOccurred: z.NmiOccurred,
+		TStatesPart: z.TStatesPart,
+		TStates:     z.TStates,
 		MemPtr:      z.MemPtr,
+
+		intData:    z.intData,
+		intPending: z.intPending,
+		nmiPending: z.nmiPending,
 	}
 }
 
-//func (z *CPU) PC() uint16 {
-//	return z.PC
-//}
-
 // ClearCodeCoverage - clears code coverage journal
 func (z *CPU) ClearCodeCoverage() {
 	clear(z.codeCoverage)

helper.go

@@ -183,11 +183,11 @@ func (z *CPU) DebugOutput() {
 		z.IX, z.IY, z.I, z.R)
 
 	log.Debugf("\t(%02X %02X %02X %02X), cycleCount: %d\n", z.rb(z.PC), z.rb(z.PC+1),
-		z.rb(z.PC+2), z.rb(z.PC+3), z.cycleCount)
+		z.rb(z.PC+2), z.rb(z.PC+3), z.TStates)
 }
 
 func (z *CPU) Reset() {
-	z.cycleCount = 0
+	z.TStates = 0
 	z.PC = 0
 	z.SP = 0xFFFF
 	z.IX = 0
@@ -221,7 +221,5 @@ func (z *CPU) Reset() {
 	z.Iff1 = false
 	z.Iff2 = false
 	z.Halted = false
-	z.IntOccurred = false
-	z.NmiOccurred = false
 	z.intData = 0
 }

opcodes.go

@@ -30,7 +30,7 @@ func (z *CPU) condCall(condition bool) {
 	addr := z.nextW()
 	if condition {
 		z.call(addr)
-		z.cycleCount += 7
+		z.TStates += 7
 	}
 	z.MemPtr = addr
 }
@@ -45,7 +45,7 @@ func (z *CPU) ret() {
 func (z *CPU) condRet(condition bool) {
 	if condition {
 		z.ret()
-		z.cycleCount += 6
+		z.TStates += 6
 	}
 }
 
@@ -62,7 +62,7 @@ func (z *CPU) condJr(condition bool) {
 	b := z.nextB()
 	if condition {
 		z.jr(b)
-		z.cycleCount += 5
+		z.TStates += 5
 	}
 }
 
@@ -99,16 +99,17 @@ func (z *CPU) subB(a byte, b byte, cy bool) byte {
 func (z *CPU) addW(a uint16, b uint16, cy bool) uint16 {
 	lsb := z.addB(byte(a), byte(b), cy)
 	msb := z.addB(byte(a>>8), byte(b>>8), z.Flags.C)
-	result := (uint16(msb) << 8) | uint16(lsb)
-	z.Flags.Z = result == 0
-	z.MemPtr = a + 1
-	return result
+	return z.addSubRes(a, msb, lsb)
 }
 
 // subW Subtracts two words (with optional carry)
 func (z *CPU) subW(a uint16, b uint16, cy bool) uint16 {
 	lsb := z.subB(byte(a), byte(b), cy)
 	msb := z.subB(byte(a>>8), byte(b>>8), z.Flags.C)
+	return z.addSubRes(a, msb, lsb)
+}
+
+func (z *CPU) addSubRes(a uint16, msb uint8, lsb uint8) uint16 {
 	result := (uint16(msb) << 8) | uint16(lsb)
 	z.Flags.Z = result == 0
 	z.MemPtr = a + 1
@@ -174,39 +175,25 @@ func (z *CPU) dec(a byte) byte {
 // executes A logic "and" between register A and A byte, then stores the
 // result in register A
 func (z *CPU) lAnd(val byte) {
-	result := z.A & val
-	z.Flags.S = result&0x80 != 0
-	z.Flags.Z = result == 0
-	z.Flags.H = true
-	z.Flags.P = parity(result)
-	z.Flags.N = false
-	z.Flags.C = false
-	z.updateXY(result)
-	z.A = result
+	z.lCmn(z.A&val, true)
 }
 
 // executes A logic "xor" between register A and A byte, then stores the
 // result in register A
 func (z *CPU) lXor(val byte) {
-	result := z.A ^ val
-	z.Flags.S = result&0x80 != 0
-	z.Flags.Z = result == 0
-	z.Flags.H = false
-	z.Flags.P = parity(result)
-	z.Flags.N = false
-	z.Flags.C = false
-	z.updateXY(result)
-	z.A = result
+	z.lCmn(z.A^val, false)
 }
 
 // executes A logic "or" between register A and A byte, then stores the
 // result in register A
 func (z *CPU) lOr(val byte) {
-	result := z.A | val
+	z.lCmn(z.A|val, false)
+}
 
+func (z *CPU) lCmn(result byte, hf bool) {
 	z.Flags.S = result&0x80 != 0
 	z.Flags.Z = result == 0
-	z.Flags.H = false
+	z.Flags.H = hf
 	z.Flags.P = parity(result)
 	z.Flags.N = false
 	z.Flags.C = false
@@ -217,11 +204,6 @@ func (z *CPU) lOr(val byte) {
 // compares A value with register A
 func (z *CPU) cp(val byte) {
 	z.subB(z.A, val, false)
-
-	// the only difference between cp and sub is that
-	// the xf/yf are taken from the value to be subtracted,
-	// not the result
-
 	z.updateXY(val)
 }
 
@@ -538,31 +520,37 @@ func (z *CPU) processInterrupts() {
 
 	if z.nmiPending {
 		z.nmiPending = false
+		if z.Halted {
+			z.PC++
 			z.Halted = false
+		}
 		z.Iff1 = false
 		z.incR()
 
-		z.cycleCount += 11
+		z.TStates += 11
 		z.call(0x0066)
 		return
 	}
 
 	if z.intPending && z.Iff1 {
 		z.intPending = false
+		if z.Halted {
+			z.PC++
 			z.Halted = false
+		}
 		z.Iff1 = false
 		z.Iff2 = false
 		z.incR()
 
 		switch z.IMode {
 		case 0:
-			z.cycleCount += 11
+			z.TStates += 11
 			z.execOpcode(z.intData)
 		case 1:
-			z.cycleCount += 13
+			z.TStates += 13
 			z.call(0x38)
 		case 2:
-			z.cycleCount += 19
+			z.TStates += 19
 			z.call(z.rw((uint16(z.I) << 8) | uint16(z.intData)))
 		default:
 			log.Errorf("Unsupported interrupt mode %d\n", z.IMode)
@@ -584,7 +572,7 @@ func (z *CPU) GenINT(data byte) {
 
 // executes A non-prefixed opcode
 func (z *CPU) execOpcode(opcode byte) {
-	z.cycleCount += uint32(cycles00[opcode])
+	z.TStates += uint32(cycles00[opcode])
 	z.incR()
 
 	switch opcode {

opcodesCB.go

@@ -4,7 +4,7 @@ import log "github.com/sirupsen/logrus"
 
 // executes A CB opcode
 func (z *CPU) execOpcodeCB(opcode byte) {
-	z.cycleCount += 8
+	z.TStates += 8
 	z.incR()
 
 	// decoding instructions from http://z80.info/decoding.htm#cb
@@ -64,7 +64,7 @@ func (z *CPU) execOpcodeCB(opcode byte) {
 		// in bit (hl), x/y flags are handled differently:
 		if z_ == 6 {
 			z.updateXY(byte(z.MemPtr >> 8))
-			z.cycleCount += 4
+			z.TStates += 4
 		}
 
 	case 2:
@@ -74,7 +74,7 @@ func (z *CPU) execOpcodeCB(opcode byte) {
 	}
 
 	if (x_ == 0 || x_ == 2 || x_ == 3) && z_ == 6 {
-		z.cycleCount += 7
+		z.TStates += 7
 	}
 
 	if reg == &hl {
@@ -154,9 +154,9 @@ func (z *CPU) execOpcodeDcb(opcode byte, addr uint16) {
 
 	if x_ == 1 {
 		// bit instructions take 20 cycles, others take 23
-		z.cycleCount += 20
+		z.TStates += 20
 	} else {
 		z.wb(addr, result)
-		z.cycleCount += 23
+		z.TStates += 23
 	}
 }

opcodesDDFD.go

@@ -2,7 +2,7 @@ package z80go
 
 // executes A DD/FD opcode (IZ = IX or IY)
 func (z *CPU) execOpcodeDDFD(opcode byte, iz *uint16) {
-	z.cycleCount += uint32(cyclesDDFD[opcode])
+	z.TStates += uint32(cyclesDDFD[opcode])
 	z.incR()
 
 	switch opcode {

opcodesED.go

@@ -4,7 +4,7 @@ import log "github.com/sirupsen/logrus"
 
 // executes A ED opcode
 func (z *CPU) execOpcodeED(opcode byte) {
-	z.cycleCount += uint32(cyclesED[opcode])
+	z.TStates += uint32(cyclesED[opcode])
 	z.incR()
 	switch opcode {
 	case 0x47:
@@ -43,7 +43,7 @@ func (z *CPU) execOpcodeED(opcode byte) {
 
 			if z.GetBC() != 0 {
 				z.PC -= 2
-				z.cycleCount += 5
+				z.TStates += 5
 				z.MemPtr = z.PC + 1
 			}
 		} // ldir
@@ -56,7 +56,7 @@ func (z *CPU) execOpcodeED(opcode byte) {
 
 			if z.GetBC() != 0 {
 				z.PC -= 2
-				z.cycleCount += 5
+				z.TStates += 5
 				z.MemPtr = z.PC + 1
 			}
 		} // lddr
@@ -70,7 +70,7 @@ func (z *CPU) execOpcodeED(opcode byte) {
 		z.cpi()
 		if z.GetBC() != 0 && !z.Flags.Z {
 			z.PC -= 2
-			z.cycleCount += 5
+			z.TStates += 5
 			z.MemPtr = z.PC + 1
 		} else {
 			//z.mem_ptr++
@@ -81,7 +81,7 @@ func (z *CPU) execOpcodeED(opcode byte) {
 		z.cpd()
 		if z.GetBC() != 0 && !z.Flags.Z {
 			z.PC -= 2
-			z.cycleCount += 5
+			z.TStates += 5
 			z.MemPtr = z.PC + 1
 		} else {
 			//z.mem_ptr++
@@ -128,7 +128,7 @@ func (z *CPU) execOpcodeED(opcode byte) {
 		z.ini()
 		if z.B > 0 {
 			z.PC -= 2
-			z.cycleCount += 5
+			z.TStates += 5
 		}
 	case 0xAA:
 		// ind
@@ -138,7 +138,7 @@ func (z *CPU) execOpcodeED(opcode byte) {
 		z.ind()
 		if z.B > 0 {
 			z.PC -= 2
-			z.cycleCount += 5
+			z.TStates += 5
 		}
 	case 0x41:
 		z.core.IOWrite(z.GetBC(), z.B) // out (c), b
@@ -172,7 +172,7 @@ func (z *CPU) execOpcodeED(opcode byte) {
 		z.outi()
 		if z.B > 0 {
 			z.PC -= 2
-			z.cycleCount += 5
+			z.TStates += 5
 		}
 	case 0xAB:
 		z.outd() // outd
@@ -180,7 +180,7 @@ func (z *CPU) execOpcodeED(opcode byte) {
 		// otdr
 		z.outd()
 		if z.B > 0 {
-			z.cycleCount += 5
+			z.TStates += 5
 			z.PC -= 2
 		}
 

z80go.go

@@ -106,17 +106,19 @@ type CPU struct {
 	Iff1        bool   `json:"iff1,omitempty"`
 	Iff2        bool   `json:"iff2,omitempty"`
 	Halted      bool   `json:"halted,omitempty"`
-	CycleCount  uint32 `json:"cycleCount,omitempty"`
-	IntOccurred bool   `json:"intOccurred,omitempty"`
-	NmiOccurred bool   `json:"interruptOccurred,omitempty"`
+	TStatesPart uint32 `json:"TStatesPart,omitempty"`
+
 	// mw hidden register
 	MemPtr uint16
 
 	// methods to access CPU to memory and IO ports of computer
 	core MemIoRW
+
+	// Data-Bus state for IM2 INT
 	intData byte
 	// Total CPU cycle count (t-states)
-	cycleCount uint32
+	TStates uint32
+
 	// map of memory access
 	memAccess map[uint16]byte
 	// enable or disable code coverage marking
@@ -129,7 +131,10 @@ type CPU struct {
 	extendedStack map[uint16]PushValueType
 
 	iffDelay byte
+	// intPending is true if Interrupt is pending
 	intPending bool
+
+	// nmiPending is true if Interrupt is pending
 	nmiPending bool
 }
 

z80go_test.go

@@ -438,9 +438,7 @@ func setComputerState(test Z80TestIn) {
 		Iff1:        test.state.IFF1,
 		Iff2:        test.state.IFF2,
 		Halted:      test.state.isHalted,
-		CycleCount:  0,
-		IntOccurred: false,
-		NmiOccurred: false,
+		TStatesPart: 0,
 		MemPtr:      test.registers.MemPtr,
 	}