Implementing the EOR

sources/CPU/CPU.hpp

@@ -395,6 +395,8 @@ namespace ComSquare::CPU
 		int INC(uint24_t, AddressingMode);
 		//! @brief Decrement
 		int DEC(uint24_t, AddressingMode);
+		//! @brief XOR, Exclusive OR accumulator with memory.
+		int EOR(uint24_t, AddressingMode);
 
 		//! @brief All the instructions of the CPU.
 		//! @info Instructions are indexed by their opcode
@@ -464,37 +466,37 @@ namespace ComSquare::CPU
 			{&CPU::BRK, 7, "rol #-#", AddressingMode::Implied, 2}, // 3E
 			{&CPU::AND, 5, "and", AddressingMode::AbsoluteIndexedByXLong, 4}, // 3F
 			{&CPU::RTI, 6, "rti", AddressingMode::Implied, 1}, // 40
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 41
+			{&CPU::EOR, 6, "eor", AddressingMode::DirectPageIndirectIndexedByX, 2}, // 41
 			{&CPU::BRK, 7, "wdm #-#", AddressingMode::Implied, 2}, // 42
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 43
+			{&CPU::EOR, 4, "eor", AddressingMode::StackRelative, 2}, // 43
 			{&CPU::BRK, 7, "mvp #-#", AddressingMode::Implied, 2}, // 44
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 45
+			{&CPU::EOR, 3, "eor", AddressingMode::DirectPage, 2}, // 45
 			{&CPU::BRK, 7, "lsr #-#", AddressingMode::Implied, 2}, // 46
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 47
+			{&CPU::EOR, 6, "eor", AddressingMode::DirectPageIndirectLong, 2}, // 47
 			{&CPU::PHA, 3, "pha", AddressingMode::Implied, 1}, // 48
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 49
+			{&CPU::EOR, 2, "eor", AddressingMode::ImmediateForA, 2}, // 49
 			{&CPU::BRK, 7, "lsr #-#", AddressingMode::Implied, 2}, // 4A
 			{&CPU::PHK, 3, "phk", AddressingMode::Implied, 1}, // 4B
 			{&CPU::JMP, 3, "jmp", AddressingMode::Absolute, 3}, // 4C
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 4D
+			{&CPU::EOR, 4, "eor", AddressingMode::Absolute, 3}, // 4D
 			{&CPU::BRK, 7, "lsr #-#", AddressingMode::Implied, 2}, // 4E
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 4F
+			{&CPU::EOR, 5, "eor", AddressingMode::AbsoluteLong, 4}, // 4F
 			{&CPU::BVC, 2, "bvc", AddressingMode::Implied, 2}, // 50
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 51
+			{&CPU::EOR, 5, "eor", AddressingMode::DirectPageIndirectIndexedByY, 2}, // 51
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 52
+			{&CPU::EOR, 5, "eor", AddressingMode::DirectPageIndirect, 2}, // 52
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 53
+			{&CPU::EOR, 4, "eor", AddressingMode::StackRelativeIndirectIndexedByY, 2}, // 53
 			{&CPU::BRK, 7, "mvn #-#", AddressingMode::Implied, 2}, // 54
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 55
+			{&CPU::EOR, 4, "eor", AddressingMode::DirectPageIndexedByX, 2}, // 55
 			{&CPU::BRK, 7, "lsr #-#", AddressingMode::Implied, 2}, // 56
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 57
+			{&CPU::EOR, 6, "eor", AddressingMode::DirectPageIndirectIndexedByYLong, 2}, // 57
 			{&CPU::CLI, 2, "cli", AddressingMode::Implied, 1}, // 58
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 59
+			{&CPU::EOR, 4, "eor", AddressingMode::AbsoluteIndexedByY, 3}, // 59
 			{&CPU::PHY, 3, "phy", AddressingMode::Implied, 1}, // 5A
 			{&CPU::BRK, 7, "tcd #-#", AddressingMode::Implied, 2}, // 5B
 			{&CPU::JML, 4, "jml", AddressingMode::Implied, 4}, // 5C
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 5D
+			{&CPU::EOR, 4, "eor", AddressingMode::AbsoluteIndexedByX, 3}, // 5D
 			{&CPU::BRK, 7, "lsr #-#", AddressingMode::Implied, 2}, // 5E
-			{&CPU::BRK, 7, "eor #-#", AddressingMode::Implied, 2}, // 5F
+			{&CPU::EOR, 5, "eor", AddressingMode::AbsoluteIndexedByXLong, 4}, // 5F
 			{&CPU::RTL, 6, "rtl", AddressingMode::Implied, 1}, // 60
 			{&CPU::ADC, 6, "adc", AddressingMode::DirectPageIndirectIndexedByX, 2}, // 61
 			{&CPU::BRK, 7, "per #-#", AddressingMode::Implied, 2}, // 62

sources/CPU/Instructions/MathematicalOperations.cpp

@@ -365,4 +365,37 @@ namespace ComSquare::CPU
 			return 0;
 		}
 	}
+
+	int CPU::EOR(uint24_t valueAddr, AddressingMode mode)
+	{
+		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;
+		this->_registers.a ^= value;
+		this->_registers.p.z = this->_registers.a == 0;
+		this->_registers.p.n = this->_registers.a & negativeMask;
+
+		int cycles = !this->_registers.p.m;
+		switch (mode) {
+		case DirectPage:
+		case DirectPageIndirect:
+		case DirectPageIndirectLong:
+		case DirectPageIndexedByX:
+		case DirectPageIndirectIndexedByX:
+		case DirectPageIndirectIndexedByYLong:
+			cycles += this->_registers.dl != 0;
+			break;
+		case AbsoluteIndexedByX:
+		case AbsoluteIndexedByY:
+			cycles += this->_hasIndexCrossedPageBoundary;
+			break;
+		case DirectPageIndirectIndexedByY:
+			cycles += this->_registers.dl != 0 + this->_hasIndexCrossedPageBoundary;
+			break;
+		default:
+			break;
+		}
+		return cycles;
+	}
 }

tests/CPU/Math/testOthersMath.cpp

@@ -284,4 +284,40 @@ Test(DEC, negativeNativeAccumulator)
 	cr_assert_eq(snes.cpu->_registers.a, 0x9000, "The incremented value should be 0x9000 but it was 0x%x.", snes.cpu->_registers.a);
 	cr_assert_eq(snes.cpu->_registers.p.n, true, "The negative flags should be set.");
 	cr_assert_eq(snes.cpu->_registers.p.z, false, "The zero flags should not be set.");
-}
+}
+
+Test(EOR, simple)
+{
+	Init()
+	snes.cpu->_registers.p.m = true;
+	snes.cpu->_registers.a = 0x80;
+	snes.wram->_data[0] = 0x0F;
+	snes.cpu->EOR(0x0, ComSquare::CPU::AddressingMode::Implied);
+	cr_assert_eq(snes.cpu->_registers.a, 0x8F, "The accumulator's value should be 0x8F but it was 0x%x.", snes.cpu->_registers.a);
+	cr_assert_eq(snes.cpu->_registers.p.n, true, "The negative flags should be set.");
+	cr_assert_eq(snes.cpu->_registers.p.z, false, "The zero flags should not be set.");
+}
+
+Test(EOR, simple2)
+{
+	Init()
+	snes.cpu->_registers.p.m = true;
+	snes.cpu->_registers.a = 0x80;
+	snes.wram->_data[0] = 0xF0;
+	snes.cpu->EOR(0x00, ComSquare::CPU::AddressingMode::Implied);
+	cr_assert_eq(snes.cpu->_registers.a, 0x70, "The accumulator's value should be 0x70 but it was 0x%x.", snes.cpu->_registers.a);
+	cr_assert_eq(snes.cpu->_registers.p.n, false, "The negative flags should not be set.");
+	cr_assert_eq(snes.cpu->_registers.p.z, false, "The zero flags should not be set.");
+}
+
+Test(EOR, zero)
+{
+	Init()
+	snes.cpu->_registers.p.m = true;
+	snes.cpu->_registers.a = 0x00;
+	snes.wram->_data[0] = 0x00;
+	snes.cpu->EOR(0x0, ComSquare::CPU::AddressingMode::Implied);
+	cr_assert_eq(snes.cpu->_registers.a, 0x00, "The accumulator's value should be 0x00 but it was 0x%x.", snes.cpu->_registers.a);
+	cr_assert_eq(snes.cpu->_registers.p.n, false, "The negative flags should not be set.");
+	cr_assert_eq(snes.cpu->_registers.p.z, true, "The zero flags should be set.");
+}