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Implementing the INC

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This commit is contained in:
Anonymus Raccoon
2020-04-06 17:59:25 +02:00
parent 724a2ca616
commit 5ded0b44e8
3 changed files with 114 additions and 6 deletions
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sources/CPU/CPU.hpp
+7 -5
View File
@@ -391,6 +391,8 @@ namespace ComSquare::CPU
int RTL(uint24_t, AddressingMode);
//! @brief Compare Accumulator with Memory.
int CMP(uint24_t, AddressingMode);
//! @brief Increment
int INC(uint24_t, AddressingMode);
//! @brief All the instructions of the CPU.
//! @info Instructions are indexed by their opcode
@@ -421,7 +423,7 @@ namespace ComSquare::CPU
{&CPU::ORA, 6, "ora", AddressingMode::DirectPageIndirectIndexedByYLong, 2}, // 17
{&CPU::CLC, 2, "clc", AddressingMode::Implied, 1}, // 18
{&CPU::ORA, 4, "ora", AddressingMode::AbsoluteIndexedByY, 3}, // 19
{&CPU::BRK, 7, "inc #-#", AddressingMode::Implied, 2}, // 1A
{&CPU::INC, 2, "inc", AddressingMode::Implied, 1}, // 1A
{&CPU::BRK, 7, "tcs #-#", AddressingMode::Implied, 2}, // 1B
{&CPU::BRK, 7, "trb #-#", AddressingMode::Implied, 2}, // 1C
{&CPU::ORA, 4, "ora", AddressingMode::AbsoluteIndexedByX, 3}, // 1D
@@ -625,7 +627,7 @@ namespace ComSquare::CPU
{&CPU::SBC, 4, "sbc", AddressingMode::StackRelative, 2}, // E3
{&CPU::CPX, 3, "cpx", AddressingMode::DirectPage, 2}, // E4
{&CPU::SBC, 3, "sbc", AddressingMode::DirectPage, 2}, // E5
{&CPU::BRK, 7, "inc #-#", AddressingMode::Implied, 2}, // E6
{&CPU::INC, 5, "inc", AddressingMode::DirectPage, 2}, // E6
{&CPU::SBC, 6, "sbc", AddressingMode::DirectPageIndirectLong, 2}, // E7
{&CPU::INX, 2, "inx", AddressingMode::Implied, 1}, // E8
{&CPU::SBC, 2, "sbc", AddressingMode::ImmediateForA, 2}, // E9
@@ -633,7 +635,7 @@ namespace ComSquare::CPU
{&CPU::BRK, 7, "xba #-#", AddressingMode::Implied, 2}, // EB
{&CPU::CPX, 4, "cpx", AddressingMode::Absolute, 3}, // EC
{&CPU::SBC, 4, "sbc", AddressingMode::Absolute, 3}, // ED
{&CPU::BRK, 7, "inc #-#", AddressingMode::Implied, 2}, // EE
{&CPU::INC, 6, "inc", AddressingMode::Absolute, 3}, // EE
{&CPU::SBC, 5, "sbc", AddressingMode::AbsoluteLong, 4}, // EF
{&CPU::BEQ, 2, "beq", AddressingMode::Implied, 2}, // F0
{&CPU::SBC, 5, "sbc", AddressingMode::DirectPageIndirectIndexedByY, 2}, // F1
@@ -641,7 +643,7 @@ namespace ComSquare::CPU
{&CPU::SBC, 7, "sbc", AddressingMode::StackRelativeIndirectIndexedByY, 2}, // F3
{&CPU::BRK, 7, "pea #-#", AddressingMode::Implied, 2}, // F4
{&CPU::SBC, 4, "sbc", AddressingMode::DirectPageIndexedByX, 2}, // F5
{&CPU::BRK, 7, "inc #-#", AddressingMode::Implied, 2}, // F6
{&CPU::INC, 6, "inc", AddressingMode::DirectPageIndexedByX, 2}, // F6
{&CPU::SBC, 6, "sbc", AddressingMode::DirectPageIndirectIndexedByYLong, 2}, // F7
{&CPU::SED, 2, "sed", AddressingMode::Implied, 1}, // F8
{&CPU::SBC, 4, "sbc", AddressingMode::AbsoluteIndexedByY, 3}, // F9
@@ -649,7 +651,7 @@ namespace ComSquare::CPU
{&CPU::XCE, 2, "xce", AddressingMode::Implied, 1}, // FB
{&CPU::JSR, 8, "jsr", AddressingMode::AbsoluteIndirectIndexedByX, 3}, // FC
{&CPU::SBC, 4, "sbc", AddressingMode::AbsoluteIndexedByX, 3}, // FD
{&CPU::BRK, 7, "inc #-#", AddressingMode::Implied, 2}, // FE
{&CPU::INC, 7, "inc", AddressingMode::AbsoluteIndexedByX, 3}, // FE
{&CPU::SBC, 5, "sbc", AddressingMode::AbsoluteIndexedByXLong, 4}, // FF
};
public:
sources/CPU/Instructions/MathematicalOperations.cpp
+41 -1
View File
@@ -254,7 +254,7 @@ namespace ComSquare::CPU
int CPU::AND(uint24_t valueAddr, AddressingMode mode)
{
unsigned negativeMask = this->_isEmulationMode ? 0x80u : 0x8000u;
unsigned negativeMask = this->_registers.p.m ? 0x80u : 0x8000u;
unsigned value = this->_bus->read(valueAddr);
if (!this->_registers.p.m)
value += this->_bus->read(valueAddr + 1) << 8u;
@@ -285,4 +285,44 @@ namespace ComSquare::CPU
}
return cycles;
}
int CPU::INC(uint24_t valueAddr, AddressingMode mode)
{
unsigned negativeMask = this->_registers.p.m ? 0x80u : 0x8000u;
unsigned result;
if (mode == Implied) {
this->_registers.a++;
if (this->_registers.p.m)
this->_registers.ah = 0;
result = this->_registers.a;
} else if (!this->_registers.p.m) {
result = this->_bus->read(valueAddr);
result += this->_bus->read(valueAddr + 1) << 8u;
result = (uint16_t)(result + 1);
this->_bus->write(valueAddr, result);
this->_bus->write(valueAddr + 1, result << 8u);
} else {
result = this->_bus->read(valueAddr);
result = (uint8_t)(result + 1);
this->_bus->write(valueAddr, result);
}
this->_registers.p.z = result == 0;
this->_registers.p.n = result & negativeMask;
switch (mode) {
case Implied:
return 0;
case Absolute:
return this->_registers.p.m == 0 ? 2 : 0;
case DirectPage:
case DirectPageIndexedByX:
return (this->_registers.p.m == 0 ? 2 : 0) + this->_registers.dl != 0 ;
case AbsoluteIndexedByX:
return (this->_registers.p.m == 0 ? 2 : 0) + this->_hasIndexCrossedPageBoundary;
default:
return 0;
}
}
}