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Adding the reset

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This commit is contained in:
AnonymusRaccoon
2020-02-12 16:40:06 +01:00
parent 8addb29610
commit 17c0cb8660
3 changed files with 53 additions and 4 deletions
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sources/CPU/CPU.cpp
+23 -3
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@@ -15,7 +15,7 @@ namespace ComSquare::CPU
CPU::CPU(std::shared_ptr<Memory::MemoryBus> bus, Cartridge::Header &cartridgeHeader)
: _bus(std::move(bus)), _cartridgeHeader(cartridgeHeader)
{
this->_registers.pc = this->_cartridgeHeader.emulationInterrupts.reset;
this->RESB();
}
//! @bref The CPU's internal registers starts at $4200 and finish at $421F.
@@ -220,11 +220,31 @@ namespace ComSquare::CPU
case Instructions::ADC_SRYi: return 7 + this->ADC(this->_getStackRelativeIndirectIndexedYAddr());
default:
return 0;
//throw InvalidOpcode("CPU", opcode);
throw InvalidOpcode("CPU", opcode);
}
}
void CPU::push(uint8_t data)
{
this->_bus->write(this->_registers.s--, data);
}
void CPU::push(uint16_t data)
{
this->_bus->write(this->_registers.s--, data);
this->_bus->write(this->_registers.s--, data << 8u);
}
uint8_t CPU::pop()
{
return this->_bus->read(this->_registers.s++);
}
uint16_t CPU::pop16()
{
return this->_bus->read(this->_registers.s++) + (this->_bus->read(this->_registers.s++) << 8u);
}
////////////////////////////////////////////////////////////////////
/// Addressing modes
////////////////////////////////////////////////////////////////////
sources/CPU/CPU.hpp
+13 -1
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@@ -202,7 +202,7 @@ namespace ComSquare::CPU
ADC_DPYil = 0x77,
ADC_ABSY = 0x79,
ADC_ABSX = 0x7D,
ADC_ABSXl = 0x7F
ADC_ABSXl = 0x7F,
};
//! @brief The main CPU
@@ -264,10 +264,22 @@ namespace ComSquare::CPU
uint24_t _getStackRelativeIndirectIndexedYAddr();
//! @brief Push 8 bits of data to the stack.
void push(uint8_t data);
//! @brief Push 16 bits of data to the stack.
void push(uint16_t data);
//! @brief Pop 8 bits of data from the stack.
uint8_t pop();
//! @brief Pop 16 bits of data from the stack.
uint16_t pop16();
//! @brief Execute a single instruction.
//! @return The number of CPU cycles that the instruction took.
unsigned executeInstruction();
//! @brief Reset interrupt - Called on boot and when the reset button is pressed.
unsigned RESB();
//! @brief Break instruction - Causes a software break. The PC is loaded from a vector table.
unsigned BRK();
//! @brief Add with carry - Adds operand to the Accumulator; adds an additional 1 if carry is set.
sources/CPU/Instructions/Interrupts.cpp
+17
View File
@@ -6,8 +6,25 @@
namespace ComSquare::CPU
{
unsigned CPU::RESB()
{
this->_registers.p.i = true;
this->_registers.p.d = false;
this->_isEmulationMode = true;
this->_registers.p.m = true;
this->_registers.p.x_b = true;
this->_registers.dbr = 0x00;
this->_registers.pbr = 0x00;
this->_registers.d = 0x0000;
this->_registers.sh = 0x01; // the low bit of the stack pointer is undefined on reset.
this->_registers.pc = this->_cartridgeHeader.emulationInterrupts.reset;
return 0;
}
unsigned CPU::BRK()
{
// TODO rework this. The PC should be pushed to the stack.
// Info here: http://softpixel.com/~cwright/sianse/docs/65816NFO.HTM at BRK Software Break
this->_registers.pc += 2;
this->_registers.p.i = true;