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Start adding enough infrastructure to support memory mapped IO on LR35902.

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Signed-off-by: Adrian.Conlon <adrian.conlon@gmail.com>
This commit is contained in:
Adrian.Conlon 2017-07-18 00:13:41 +01:00
parent 627d30e896
commit 35def4184a
3 changed files with 89 additions and 37 deletions
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36
LR35902/inc/LR35902.h
View File

@ -56,9 +56,45 @@ namespace EightBit {
virtual void reset();
virtual void initialise();
protected:
virtual uint8_t fetchByte() {
auto returned = IntelProcessor::fetchByte();
m_memory.fireReadBusEvent();
return returned;
}
virtual void push(uint8_t value) {
IntelProcessor::push(value);
m_memory.fireWriteBusEvent();
}
virtual uint8_t pop() {
auto returned = IntelProcessor::pop();
m_memory.fireReadBusEvent();
return returned;
}
virtual void getWordViaMemptr(register16_t& value) {
value.low = memptrReference();
m_memory.fireReadBusEvent();
m_memory.ADDRESS().word++;
value.high = m_memory.reference();
m_memory.fireReadBusEvent();
}
virtual void setWordViaMemptr(register16_t value) {
memptrReference() = value.low;
m_memory.fireWriteBusEvent();
m_memory.ADDRESS().word++;
m_memory.reference() = value.high;
m_memory.fireWriteBusEvent();
}
private:
enum { BC_IDX, DE_IDX, HL_IDX };
Bus& m_bus;
std::array<register16_t, 3> m_registers;
register16_t m_accumulatorFlag;

80
LR35902/src/LR35902.cpp
View File

@ -6,6 +6,7 @@
EightBit::LR35902::LR35902(Bus& memory)
: IntelProcessor(memory),
m_bus(memory),
m_ime(false),
m_prefixCB(false) {
}
@ -464,26 +465,34 @@ void EightBit::LR35902::executeCB(int x, int y, int z, int p, int q) {
}
adjustZero<LR35902>(F(), R(z));
cycles += 2;
if (z == 6)
if (z == 6) {
m_bus.fireWriteBusEvent();
cycles += 2;
}
break;
case 1: // BIT y, r[z]
bit(y, R(z));
cycles += 2;
if (z == 6)
if (z == 6) {
m_bus.fireReadBusEvent();
cycles += 2;
}
break;
case 2: // RES y, r[z]
res(y, R(z));
cycles += 2;
if (z == 6)
if (z == 6) {
m_bus.fireWriteBusEvent();
cycles += 2;
}
break;
case 3: // SET y, r[z]
set(y, R(z));
cycles += 2;
if (z == 6)
if (z == 6) {
m_bus.fireWriteBusEvent();
cycles += 2;
}
break;
}
}
@ -538,23 +547,19 @@ void EightBit::LR35902::executeOther(int x, int y, int z, int p, int q) {
case 0:
switch (p) {
case 0: // LD (BC),A
m_memory.ADDRESS() = BC();
m_memory.reference() = A();
m_memory.write(BC().word, A());
cycles += 2;
break;
case 1: // LD (DE),A
m_memory.ADDRESS() = DE();
m_memory.reference() = A();
m_memory.write(DE().word, A());
cycles += 2;
break;
case 2: // GB: LDI (HL),A
m_memory.ADDRESS().word = HL().word++;
m_memory.reference() = A();
m_memory.write(HL().word++, A());
cycles += 2;
break;
case 3: // GB: LDD (HL),A
m_memory.ADDRESS().word = HL().word--;
m_memory.reference() = A();
m_memory.write(HL().word--, A());
cycles += 2;
break;
}
@ -562,23 +567,19 @@ void EightBit::LR35902::executeOther(int x, int y, int z, int p, int q) {
case 1:
switch (p) {
case 0: // LD A,(BC)
m_memory.ADDRESS() = BC();
A() = m_memory.reference();
A() = m_memory.read(BC().word);
cycles += 2;
break;
case 1: // LD A,(DE)
m_memory.ADDRESS() = DE();
A() = m_memory.reference();
A() = m_memory.read(DE().word);
cycles += 2;
break;
case 2: // GB: LDI A,(HL)
m_memory.ADDRESS().word = HL().word++;
A() = m_memory.reference();
A() = m_memory.read(HL().word++);
cycles += 2;
break;
case 3: // GB: LDD A,(HL)
m_memory.ADDRESS().word = HL().word--;
A() = m_memory.reference();
A() = m_memory.read(HL().word--);
cycles += 2;
break;
}
@ -599,17 +600,23 @@ void EightBit::LR35902::executeOther(int x, int y, int z, int p, int q) {
case 4: // 8-bit INC
postIncrement(F(), ++R(y)); // INC r
cycles++;
if (y == 6)
if (y == 6) {
m_bus.fireWriteBusEvent();
cycles += 2;
}
break;
case 5: // 8-bit DEC
postDecrement(F(), --R(y)); // DEC r
cycles++;
if (y == 6)
if (y == 6) {
m_bus.fireWriteBusEvent();
cycles += 2;
}
break;
case 6: // 8-bit load immediate
R(y) = fetchByte();
if (y == 6)
m_bus.fireWriteBusEvent();
cycles += 2;
break;
case 7: // Assorted operations on accumulator/flags
@ -652,9 +659,14 @@ void EightBit::LR35902::executeOther(int x, int y, int z, int p, int q) {
halt();
} else {
R(y) = R(z);
if ((y == 6) || (z == 6)) // M operations
if ((y == 6) || (z == 6)) { // M operations
if (y == 6)
m_bus.fireWriteBusEvent();
else
m_bus.fireReadBusEvent();
cycles++;
}
}
cycles++;
break;
case 2: // Operate on accumulator and register/memory location
@ -685,8 +697,10 @@ void EightBit::LR35902::executeOther(int x, int y, int z, int p, int q) {
break;
}
cycles++;
if (z == 6)
if (z == 6) {
m_bus.fireReadBusEvent();
cycles++;
}
break;
case 3:
switch (z) {
@ -698,8 +712,8 @@ void EightBit::LR35902::executeOther(int x, int y, int z, int p, int q) {
} else {
switch (y) {
case 4: // GB: LD (FF00 + n),A
m_memory.ADDRESS().word = 0xff00 + fetchByte();
m_memory.reference() = A();
m_bus.REG(fetchByte()) = A();
m_bus.fireWriteBusEvent();
cycles += 3;
break;
case 5: { // GB: ADD SP,dd
@ -715,8 +729,8 @@ void EightBit::LR35902::executeOther(int x, int y, int z, int p, int q) {
cycles += 4;
break;
case 6: // GB: LD A,(FF00 + n)
m_memory.ADDRESS().word = 0xff00 + fetchByte();
A() = m_memory.reference();
A() = m_bus.REG(fetchByte());
m_bus.fireReadBusEvent();
cycles += 3;
break;
case 7: { // GB: LD HL,SP + dd
@ -768,25 +782,27 @@ void EightBit::LR35902::executeOther(int x, int y, int z, int p, int q) {
} else {
switch (y) {
case 4: // GB: LD (FF00 + C),A
m_memory.ADDRESS().word = 0xff00 + C();
m_memory.reference() = A();
m_bus.REG(C()) = A();
m_bus.fireWriteBusEvent();
cycles += 2;
break;
case 5: // GB: LD (nn),A
fetchWord();
m_memory.ADDRESS() = MEMPTR();
m_memory.reference() = A();
m_bus.fireWriteBusEvent();
cycles += 4;
break;
case 6: // GB: LD A,(FF00 + C)
m_memory.ADDRESS().word = 0xff00 + C();
A() = m_memory.reference();
A() = m_bus.REG(C());
m_bus.fireReadBusEvent();
cycles += 2;
break;
case 7: // GB: LD A,(nn)
fetchWord();
m_memory.ADDRESS() = MEMPTR();
A() = m_memory.reference();
m_bus.fireReadBusEvent();
cycles += 4;
break;
}

10
inc/IntelProcessor.h
View File

@ -94,7 +94,7 @@ namespace EightBit {
return m_halfCarryTableSub[index & Mask3];
}
uint8_t fetchByte() {
virtual uint8_t fetchByte() {
m_memory.ADDRESS().word = PC().word++;
return m_memory.reference();
}
@ -104,7 +104,7 @@ namespace EightBit {
output.high = fetchByte();
}
void push(uint8_t value) {
virtual void push(uint8_t value) {
m_memory.ADDRESS().word = --SP().word;
m_memory.reference() = value;
}
@ -114,7 +114,7 @@ namespace EightBit {
push(value.low);
}
uint8_t pop() {
virtual uint8_t pop() {
m_memory.ADDRESS().word = SP().word++;
return m_memory.reference();
}
@ -136,13 +136,13 @@ namespace EightBit {
return m_memory.reference();
}
void getWordViaMemptr(register16_t& value) {
virtual void getWordViaMemptr(register16_t& value) {
value.low = memptrReference();
m_memory.ADDRESS().word++;
value.high = m_memory.reference();
}
void setWordViaMemptr(register16_t value) {
virtual void setWordViaMemptr(register16_t value) {
memptrReference() = value.low;
m_memory.ADDRESS().word++;
m_memory.reference() = value.high;