// // Created by anonymus-raccoon on 2/13/20. // #include "../CPU.hpp" namespace ComSquare::CPU { int CPU::STA(uint24_t addr, AddressingMode mode) { if (this->_registers.p.m) this->_bus->write(addr, this->_registers.al); else { this->_bus->write(addr, this->_registers.al); this->_bus->write(addr + 1, this->_registers.ah); } int cycles = !this->_registers.p.m; switch (mode) { case DirectPage: case DirectPageIndirect: case DirectPageIndirectLong: case DirectPageIndexedByX: case DirectPageIndirectIndexedByX: case DirectPageIndirectIndexedByY: case DirectPageIndirectIndexedByYLong: cycles += this->_registers.dl != 0; default: break; } return cycles; } int CPU::STX(uint24_t addr, AddressingMode mode) { if (this->_registers.p.x_b) this->_bus->write(addr, this->_registers.xl); else { this->_bus->write(addr, this->_registers.xl); this->_bus->write(addr + 1, this->_registers.xh); } return !this->_registers.p.x_b + (mode != Absolute && this->_registers.dl != 0); } int CPU::STY(uint24_t addr, AddressingMode mode) { if (this->_registers.p.x_b) this->_bus->write(addr, this->_registers.yl); else { this->_bus->write(addr, this->_registers.yl); this->_bus->write(addr + 1, this->_registers.yh); } return !this->_registers.p.x_b + (mode != Absolute && this->_registers.dl != 0); } int CPU::STZ(uint24_t addr, AddressingMode mode) { this->_bus->write(addr, 0x00); if (!this->_registers.p.m) this->_bus->write(addr + 1, 0x00); if (mode == Absolute || mode == AbsoluteIndexedByX) return !this->_registers.p.m; return !this->_registers.p.m + this->_registers.dl != 0; } int CPU::LDA(uint24_t addr, AddressingMode mode) { if (this->_registers.p.m) { this->_registers.a = this->_bus->read(addr); this->_registers.p.n = this->_registers.al & 0xF0u; } else { this->_registers.al = this->_bus->read(addr); this->_registers.ah = this->_bus->read(addr + 1); this->_registers.p.n = this->_registers.a & 0xF000u; } this->_registers.p.z = this->_registers.a == 0x0; 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; } int CPU::LDX(uint24_t addr, AddressingMode mode) { if (this->_registers.p.x_b) { this->_registers.x = this->_bus->read(addr); this->_registers.p.n = this->_registers.xl & 0xF0u; } else { this->_registers.xl = this->_bus->read(addr); this->_registers.xh = this->_bus->read(addr + 1); this->_registers.p.n = this->_registers.x & 0xF000u; } this->_registers.p.z = this->_registers.x == 0x0; int cycles = !this->_registers.p.x_b; switch (mode) { case DirectPage: case DirectPageIndexedByY: cycles += this->_registers.dl != 0; break; case AbsoluteIndexedByY: cycles += this->_hasIndexCrossedPageBoundary; break; default: break; } return cycles; } int CPU::LDY(uint24_t addr, AddressingMode mode) { if (this->_registers.p.x_b) { this->_registers.y = this->_bus->read(addr); this->_registers.p.n = this->_registers.yl & 0xF0u; } else { this->_registers.yl = this->_bus->read(addr); this->_registers.yh = this->_bus->read(addr + 1); this->_registers.p.n = this->_registers.y & 0xF000u; } this->_registers.p.z = this->_registers.y == 0x0; int cycles = !this->_registers.p.x_b; switch (mode) { case DirectPage: case DirectPageIndexedByY: cycles += this->_registers.dl != 0; break; case AbsoluteIndexedByY: cycles += this->_hasIndexCrossedPageBoundary; break; default: break; } return cycles; } }