use crate::utils::{ BitIndex, get_bit, set_bit, join_bytes, add_half_carry, sub_half_carry }; use crate::bus::Bus; #[derive(Debug, Copy, Clone)] pub enum Register { A, // Accumulator F, // Flags B, C, D, E, H, L, // This registers are just the same as above but combined to get a 16 bits register AF, BC, DE, HL, SP, // Stack pointer PC, // Program counter } type Rg = Register; impl Register { pub fn is_8bit(&self) -> bool { match self { Rg::A | Rg::F | Rg::B | Rg::C | Rg::D | Rg::E | Rg::H | Rg::L => true, Rg::AF | Rg::BC | Rg::DE | Rg::HL | Rg::SP | Rg::PC => false, } } pub fn is_16bit(&self) -> bool { !self.is_8bit() } } #[derive(Debug, Copy, Clone)] pub enum FlagRegister { Zero, // Set when the result of a math operation is zero or if two values matches using the CP instruction Substract, // Set if a substraction was performed in the last math instruction HalfCarry, // Set if a carry ocurred from the lower nibble in the last math operation Carry, // Set if a carry was ocurrend from the last math operation or if register A is the smaller value when executing the CP instruction } pub enum InterruptFlag { VBlank, LCDSTAT, Timer, Serial, Joypad, } impl InterruptFlag { pub fn get_bit_index(interrupt: InterruptFlag) -> BitIndex { match interrupt { InterruptFlag::VBlank => BitIndex::I0, InterruptFlag::LCDSTAT => BitIndex::I1, InterruptFlag::Timer => BitIndex::I2, InterruptFlag::Serial => BitIndex::I3, InterruptFlag::Joypad => BitIndex::I4, } } } pub struct Registers { a: u8, f: u8, b: u8, c: u8, d: u8, e: u8, h: u8, l: u8, sp: u16, pc: u16, } impl Registers { pub fn new() -> Self { Self { a: 0x01, f: 0xB0, // The first 4 lower bits are always set to 0 b: 0x00, c: 0x13, d: 0x00, e: 0xD8, h: 0x01, l: 0x4D, sp: 0xFFFE, pc: 0x0100, // On power up, the Gameboy executes the instruction at hex 100 } } pub fn get(&self, register: Register) -> u16 { match register { Register::A => self.a as u16, Register::B => self.b as u16, Register::C => self.c as u16, Register::D => self.d as u16, Register::E => self.e as u16, Register::F => self.f as u16, Register::H => self.h as u16, Register::L => self.l as u16, Register::AF => join_bytes(self.a, self.f), Register::BC => join_bytes(self.b, self.c), Register::DE => join_bytes(self.d, self.e), Register::HL => join_bytes(self.h, self.l), Register::SP => self.sp, Register::PC => self.pc, } } pub fn set(&mut self, register: Register, val: u16) { let bytes = val.to_be_bytes(); match register { Register::A => self.a = bytes[1], Register::B => self.b = bytes[1], Register::C => self.c = bytes[1], Register::D => self.d = bytes[1], Register::E => self.e = bytes[1], Register::F => self.f = bytes[1], Register::H => self.h = bytes[1], Register::L => self.l = bytes[1], Register::AF => {self.a = bytes[0];self.f = bytes[1];}, Register::BC => {self.b = bytes[0];self.c = bytes[1];}, Register::DE => {self.d = bytes[0];self.e = bytes[1];}, Register::HL => {self.h = bytes[0];self.l = bytes[1];}, Register::SP => self.sp = val, Register::PC => self.pc = val, } } pub fn get_flag(&self, flag: FlagRegister) -> bool { match flag { FlagRegister::Zero => get_bit(self.f, BitIndex::I7), FlagRegister::Substract => get_bit(self.f, BitIndex::I6), FlagRegister::HalfCarry => get_bit(self.f, BitIndex::I5), FlagRegister::Carry => get_bit(self.f, BitIndex::I4), } } pub fn set_flag(&mut self, flag: FlagRegister, val: bool) { match flag { FlagRegister::Zero => self.f = set_bit(self.f, val, BitIndex::I7), FlagRegister::Substract => self.f = set_bit(self.f, val, BitIndex::I6), FlagRegister::HalfCarry => self.f = set_bit(self.f, val, BitIndex::I5), FlagRegister::Carry => self.f = set_bit(self.f, val, BitIndex::I4), } } pub fn increment(&mut self, register: Register, times: u8) { self.set(register, self.get(register) + (times as u16)); } pub fn decrement(&mut self, register: Register, times: u8) { self.set(register, self.get(register) - (times as u16)); } } #[derive(Debug)] pub enum OpcodeParameter { Register(Register), Register_U8(Register, u8), Register_U16(Register, u16), Register_I8(Register, u8), Register_I16(Register, u16), U8_Register(u8, Register), U16_Register(u16, Register), I8_Register(u8, Register), I16_Register(u16, Register), Register_16BitAddress(Register, u16), Register_Register(Register, Register), Register_RegisterDecrement(Register, Register), RegisterDecrement_Register(Register, Register), Register_RegisterIncrement(Register, Register), RegisterIncrement_Register(Register, Register), Register_FF00plusRegister(Register, Register), FF00plusRegister_Register(Register, Register), Register_FF00plusU8(Register, u8), FF00plusU8_Register(u8, Register), Register_RegisterPlusI8(Register, Register, u8), U8(u8), I8(i8), U16(u16), I16(i16), FlagRegisterReset(FlagRegister), FlagRegisterSet(FlagRegister), FlagRegisterReset_U16(FlagRegister, u16), FlagRegisterSet_U16(FlagRegister, u16), FlagRegisterReset_I16(FlagRegister, i16), FlagRegisterSet_I16(FlagRegister, i16), FlagRegisterReset_U8(FlagRegister, u8), FlagRegisterSet_U8(FlagRegister, u8), FlagRegisterReset_I8(FlagRegister, i8), FlagRegisterSet_I8(FlagRegister, i8), NoParam, } #[derive(Debug)] pub enum Opcode { LD(OpcodeParameter), LDD(OpcodeParameter), LDI(OpcodeParameter), LDHL(OpcodeParameter), PUSH(Register), POP(Register), ADD(OpcodeParameter), ADC(OpcodeParameter), SUB(OpcodeParameter), SBC(OpcodeParameter), AND(OpcodeParameter), OR(OpcodeParameter), XOR(OpcodeParameter), CP(OpcodeParameter), INC(bool, Register), DEC(bool, Register), SWAP, DAA, CPL, CCF, SCF, NOP, HALT, STOP, DI, EI, RLCA, RLA, RRCA, RRA, RLC, RL, RRC, RR, SLA, SRA, SRL, BIT, SET, RES, JP(OpcodeParameter), JR(OpcodeParameter), CALL(OpcodeParameter), RST(u8), RET(OpcodeParameter), RETI, PrefixCB, IllegalInstruction, } pub struct CPU { registers: Registers, exec_calls_count: usize, } impl CPU { pub fn new() -> Self { Self { registers: Registers::new(), exec_calls_count: 0, } } pub fn get_exec_calls_count(&self) -> usize { self.exec_calls_count } fn increment_exec_calls_count(&mut self) { self.exec_calls_count += 1; } pub fn run(&mut self, bus: &mut Bus) { let program_counter = self.registers.get(Register::PC); let parameter_bytes = CPU::read_parameter_bytes(program_counter, bus); let opcode = CPU::parse_opcode(parameter_bytes); // println!("Opcode: {:02X?} | PC: {:04X?} | Params: {:02X?}", opcode, self.registers.get(Register::PC), ¶meter_bytes); println!("A: {:02X} F: {:02X} B: {:02X} C: {:02X} D: {:02X} E: {:02X} H: {:02X} L: {:02X} SP: {:04X} PC: 00:{:04X} ({:02X} {:02X} {:02X} {:02X})", self.registers.get(Register::A), self.registers.get(Register::F), self.registers.get(Register::B), self.registers.get(Register::C), self.registers.get(Register::D), self.registers.get(Register::E), self.registers.get(Register::H), self.registers.get(Register::L), self.registers.get(Register::SP), self.registers.get(Register::PC), parameter_bytes.0, parameter_bytes.1, parameter_bytes.2, parameter_bytes.3, ); self.exec(opcode, bus); self.increment_exec_calls_count(); } pub fn exec(&mut self, opcode: Opcode, bus: &mut Bus) { match opcode { // Load Opcode::LD(params) => match params { OpcodeParameter::Register_Register(reg1, reg2) => { if reg1.is_16bit() && reg2.is_8bit() { let val = self.registers.get(reg2).to_be_bytes()[1]; let addr = self.registers.get(reg1); bus.write(addr, val); } else if reg1.is_8bit() && reg2.is_16bit() { let val = bus.read(self.registers.get(reg2)) as u16; self.registers.set(reg1, val); } else { self.registers.set(reg1, self.registers.get(reg2)); } self.registers.increment(Register::PC, 1); }, OpcodeParameter::Register_U16(register, val) => { self.registers.set(register, val); self.registers.increment(Register::PC, 3); }, OpcodeParameter::Register_U8(register, val) => { self.registers.set(register, val as u16); self.registers.increment(Register::PC, 2); }, OpcodeParameter::U16_Register(address, register) => { let value = self.registers.get(register); let bytes = value.to_be_bytes(); match register.is_8bit() { true => bus.write(address, bytes[1]), false => bus.write_16bit(address, value), } self.registers.increment(Register::PC, 3); }, OpcodeParameter::Register_FF00plusU8(register, val) => { self.registers.set(register, bus.read(0xFF00 + (val as u16)) as u16); self.registers.increment(Register::PC, 2); }, OpcodeParameter::FF00plusU8_Register(val, register) => { match register.is_8bit() { true => bus.write(0xFF00 + (val as u16), self.registers.get(register).to_be_bytes()[1]), false => bus.write_16bit(0xFF00 + (val as u16), self.registers.get(register)), } self.registers.increment(Register::PC, 2); }, _ => {}, }, // Increment or decrement program counter by signed N Opcode::JR(params) => { self.registers.increment(Register::PC, 2); let mut condition_met = false; let mut value = 0 as i16; match params { OpcodeParameter::I8(val) => { condition_met = true; value = val as i16; }, OpcodeParameter::FlagRegisterReset_I8(flag, val) => { condition_met = !self.registers.get_flag(flag); value = val as i16; }, OpcodeParameter::FlagRegisterSet_I8(flag, val) => { condition_met = self.registers.get_flag(flag); value = val as i16; }, _ => {}, }; if condition_met { let pc = (self.registers.get(Register::PC) as i16) + (value as i16); self.registers.set(Register::PC, pc as u16); } }, // Load and increment Opcode::LDI(params) => match params { OpcodeParameter::Register_RegisterIncrement(reg1, reg2) => { let val = bus.read(self.registers.get(reg2)); self.registers.set(reg1, val as u16); self.registers.increment(reg2, 1); self.registers.increment(Register::PC, 1); }, _ => {}, }, // Increment by 1 Opcode::INC(affect_flags, register) => { let prev_value = self.registers.get(register); self.registers.increment(register, 1); if affect_flags { self.registers.set_flag(FlagRegister::Substract, false); let mut byte_compare = 0; match register.is_8bit() { true => byte_compare = prev_value.to_be_bytes()[1], false => byte_compare = prev_value.to_be_bytes()[0], } self.registers.set_flag(FlagRegister::HalfCarry, add_half_carry(byte_compare, 1)); let result = self.registers.get(register); self.registers.set_flag(FlagRegister::Zero, result == 0); } self.registers.increment(Register::PC, 1); }, // Decrement by 1 Opcode::DEC(affect_flags, register) => { let prev_value = self.registers.get(register); self.registers.decrement(register, 1); if affect_flags { self.registers.set_flag(FlagRegister::Substract, true); let mut byte_compare = 0; match register.is_8bit() { true => byte_compare = prev_value.to_be_bytes()[1], false => byte_compare = prev_value.to_be_bytes()[0], } self.registers.set_flag(FlagRegister::HalfCarry, sub_half_carry(byte_compare, 1)); let result = self.registers.get(register); self.registers.set_flag(FlagRegister::Zero, result == 0); } self.registers.increment(Register::PC, 1); }, // Jump to address Opcode::JP(params) => match params { OpcodeParameter::U16(address) => self.registers.set(Register::PC, address), _ => {}, }, // CALL Opcode::CALL(params) => match params { OpcodeParameter::U16(address) => { let pc = self.registers.get(Register::PC); self.registers.decrement(Register::SP, 2); let sp = self.registers.get(Register::SP); bus.write_16bit(sp, pc); self.registers.set(Register::PC, address); }, _ => {}, }, // RST, same as Call Opcode::RST(address) => self.exec(Opcode::CALL(OpcodeParameter::U16(address as u16)), bus), // POP Opcode::POP(register) => { if register.is_16bit() { let sp = self.registers.get(Register::SP); let val = bus.read_16bit(sp); self.registers.set(register, val); self.registers.increment(Register::SP, 2); } }, // RET, same as POP PC when no parameter is specified Opcode::RET(params) => match params { OpcodeParameter::NoParam => self.exec(Opcode::POP(Register::PC), bus), _ => {}, } // Rotate A Left Opcode::RLCA => { let val = self.registers.get(Register::A).to_be_bytes()[1]; let result = val.rotate_left(7); if get_bit(result, BitIndex::I7) { self.registers.set_flag(FlagRegister::Carry, true); } self.registers.increment(Register::PC, 1); }, // Rotate A Right Opcode::RRCA => { let val = self.registers.get(Register::A).to_be_bytes()[1]; let result = val.rotate_right(7); if get_bit(result, BitIndex::I0) { self.registers.set_flag(FlagRegister::Carry, true); } self.registers.increment(Register::PC, 1); }, // Disable interrupts Opcode::DI => { bus.write(0xFFFF, 0x00); // Disable all interrupts self.registers.increment(Register::PC, 1); }, Opcode::NOP => self.registers.increment(Register::PC, 1), _ => println!("Illegal instruction"), }; } fn read_parameter_bytes(address: u16, bus: &Bus) -> (u8, u8, u8, u8) { ( bus.read(address), bus.read(address + 1), bus.read(address + 2), bus.read(address + 3), ) } pub fn parse_opcode(params: (u8, u8, u8, u8)) -> Opcode { let opcode = params.0; let two_byte_param = join_bytes(params.2, params.1); match opcode { 0x06 => Opcode::LD(OpcodeParameter::Register_U8(Register::B, params.1)), 0x0E => Opcode::LD(OpcodeParameter::Register_U8(Register::C, params.1)), 0x16 => Opcode::LD(OpcodeParameter::Register_U8(Register::D, params.1)), 0x1E => Opcode::LD(OpcodeParameter::Register_U8(Register::E, params.1)), 0x26 => Opcode::LD(OpcodeParameter::Register_U8(Register::H, params.1)), 0x2E => Opcode::LD(OpcodeParameter::Register_U8(Register::L, params.1)), 0x7F => Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::A)), 0x78 => Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::B)), 0x79 => Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::C)), 0x7A => Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::D)), 0x7B => Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::E)), 0x7C => Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::H)), 0x7D => Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::L)), 0x7E => Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::HL)), 0x40 => Opcode::LD(OpcodeParameter::Register_Register(Register::B, Register::B)), 0x41 => Opcode::LD(OpcodeParameter::Register_Register(Register::B, Register::C)), 0x42 => Opcode::LD(OpcodeParameter::Register_Register(Register::B, Register::D)), 0x43 => Opcode::LD(OpcodeParameter::Register_Register(Register::B, Register::E)), 0x44 => Opcode::LD(OpcodeParameter::Register_Register(Register::B, Register::H)), 0x45 => Opcode::LD(OpcodeParameter::Register_Register(Register::B, Register::L)), 0x46 => Opcode::LD(OpcodeParameter::Register_Register(Register::B, Register::HL)), 0x48 => Opcode::LD(OpcodeParameter::Register_Register(Register::C, Register::B)), 0x49 => Opcode::LD(OpcodeParameter::Register_Register(Register::C, Register::C)), 0x4A => Opcode::LD(OpcodeParameter::Register_Register(Register::C, Register::D)), 0x4B => Opcode::LD(OpcodeParameter::Register_Register(Register::C, Register::E)), 0x4C => Opcode::LD(OpcodeParameter::Register_Register(Register::C, Register::H)), 0x4D => Opcode::LD(OpcodeParameter::Register_Register(Register::C, Register::L)), 0x4E => Opcode::LD(OpcodeParameter::Register_Register(Register::C, Register::HL)), 0x50 => Opcode::LD(OpcodeParameter::Register_Register(Register::D, Register::B)), 0x51 => Opcode::LD(OpcodeParameter::Register_Register(Register::D, Register::C)), 0x52 => Opcode::LD(OpcodeParameter::Register_Register(Register::D, Register::D)), 0x53 => Opcode::LD(OpcodeParameter::Register_Register(Register::D, Register::E)), 0x54 => Opcode::LD(OpcodeParameter::Register_Register(Register::D, Register::H)), 0x55 => Opcode::LD(OpcodeParameter::Register_Register(Register::D, Register::L)), 0x56 => Opcode::LD(OpcodeParameter::Register_Register(Register::D, Register::HL)), 0x58 => Opcode::LD(OpcodeParameter::Register_Register(Register::E, Register::B)), 0x59 => Opcode::LD(OpcodeParameter::Register_Register(Register::E, Register::C)), 0x5A => Opcode::LD(OpcodeParameter::Register_Register(Register::E, Register::D)), 0x5B => Opcode::LD(OpcodeParameter::Register_Register(Register::E, Register::E)), 0x5C => Opcode::LD(OpcodeParameter::Register_Register(Register::E, Register::H)), 0x5D => Opcode::LD(OpcodeParameter::Register_Register(Register::E, Register::L)), 0x5E => Opcode::LD(OpcodeParameter::Register_Register(Register::E, Register::HL)), 0x60 => Opcode::LD(OpcodeParameter::Register_Register(Register::H, Register::B)), 0x61 => Opcode::LD(OpcodeParameter::Register_Register(Register::H, Register::C)), 0x62 => Opcode::LD(OpcodeParameter::Register_Register(Register::H, Register::D)), 0x63 => Opcode::LD(OpcodeParameter::Register_Register(Register::H, Register::E)), 0x64 => Opcode::LD(OpcodeParameter::Register_Register(Register::H, Register::H)), 0x65 => Opcode::LD(OpcodeParameter::Register_Register(Register::H, Register::L)), 0x66 => Opcode::LD(OpcodeParameter::Register_Register(Register::H, Register::HL)), 0x68 => Opcode::LD(OpcodeParameter::Register_Register(Register::L, Register::B)), 0x69 => Opcode::LD(OpcodeParameter::Register_Register(Register::L, Register::C)), 0x6A => Opcode::LD(OpcodeParameter::Register_Register(Register::L, Register::D)), 0x6B => Opcode::LD(OpcodeParameter::Register_Register(Register::L, Register::E)), 0x6C => Opcode::LD(OpcodeParameter::Register_Register(Register::L, Register::H)), 0x6D => Opcode::LD(OpcodeParameter::Register_Register(Register::L, Register::L)), 0x6E => Opcode::LD(OpcodeParameter::Register_Register(Register::L, Register::HL)), 0x70 => Opcode::LD(OpcodeParameter::Register_Register(Register::HL, Register::B)), 0x71 => Opcode::LD(OpcodeParameter::Register_Register(Register::HL, Register::C)), 0x72 => Opcode::LD(OpcodeParameter::Register_Register(Register::HL, Register::D)), 0x73 => Opcode::LD(OpcodeParameter::Register_Register(Register::HL, Register::E)), 0x74 => Opcode::LD(OpcodeParameter::Register_Register(Register::HL, Register::H)), 0x75 => Opcode::LD(OpcodeParameter::Register_Register(Register::HL, Register::L)), 0x47 => Opcode::LD(OpcodeParameter::Register_Register(Register::B, Register::A)), 0x4F => Opcode::LD(OpcodeParameter::Register_Register(Register::C, Register::A)), 0x57 => Opcode::LD(OpcodeParameter::Register_Register(Register::D, Register::A)), 0x5F => Opcode::LD(OpcodeParameter::Register_Register(Register::E, Register::A)), 0x67 => Opcode::LD(OpcodeParameter::Register_Register(Register::H, Register::A)), 0x6F => Opcode::LD(OpcodeParameter::Register_Register(Register::L, Register::A)), 0x02 => Opcode::LD(OpcodeParameter::Register_Register(Register::BC, Register::A)), 0x12 => Opcode::LD(OpcodeParameter::Register_Register(Register::DE, Register::A)), 0x77 => Opcode::LD(OpcodeParameter::Register_Register(Register::HL, Register::A)), 0x36 => Opcode::LD(OpcodeParameter::Register_U8(Register::HL, params.1)), 0x0A => Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::BC)), 0x1A => Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::DE)), 0xFA => Opcode::LD(OpcodeParameter::Register_U16(Register::A, two_byte_param)), // Receives 16 bit value, but lower bit is ignored 0x3E => Opcode::LD(OpcodeParameter::Register_U8(Register::A, params.1)), 0xEA => Opcode::LD(OpcodeParameter::U16_Register(two_byte_param, Register::A)), 0xF2 => Opcode::LD(OpcodeParameter::Register_FF00plusRegister(Register::A, Register::C)), 0xE2 => Opcode::LD(OpcodeParameter::FF00plusRegister_Register(Register::A, Register::C)), 0x3A => Opcode::LDD(OpcodeParameter::Register_RegisterDecrement(Register::A, Register::HL)), 0x32 => Opcode::LDD(OpcodeParameter::RegisterDecrement_Register(Register::HL, Register::A)), 0x2A => Opcode::LDI(OpcodeParameter::Register_RegisterIncrement(Register::A, Register::HL)), 0x22 => Opcode::LDI(OpcodeParameter::RegisterIncrement_Register(Register::HL, Register::A)), 0xE0 => Opcode::LD(OpcodeParameter::FF00plusU8_Register(params.1, Register::A)), 0xF0 => Opcode::LD(OpcodeParameter::Register_FF00plusU8(Register::A, params.1)), 0x01 => Opcode::LD(OpcodeParameter::Register_U16(Register::BC, two_byte_param)), 0x11 => Opcode::LD(OpcodeParameter::Register_U16(Register::DE, two_byte_param)), 0x21 => Opcode::LD(OpcodeParameter::Register_U16(Register::HL, two_byte_param)), 0x31 => Opcode::LD(OpcodeParameter::Register_U16(Register::SP, two_byte_param)), 0xF9 => Opcode::LD(OpcodeParameter::Register_Register(Register::SP, Register::HL)), 0xF8 => Opcode::LD(OpcodeParameter::Register_RegisterPlusI8(Register::HL, Register::SP, params.1)), 0x08 => Opcode::LD(OpcodeParameter::U16_Register(two_byte_param, Register::SP)), 0xC5 => Opcode::PUSH(Register::BC), 0xD5 => Opcode::PUSH(Register::DE), 0xE5 => Opcode::PUSH(Register::HL), 0xF5 => Opcode::PUSH(Register::AF), 0xC1 => Opcode::POP(Register::BC), 0xD1 => Opcode::POP(Register::DE), 0xE1 => Opcode::POP(Register::HL), 0xF1 => Opcode::POP(Register::AF), 0x87 => Opcode::ADD(OpcodeParameter::Register_Register(Register::A, Register::A)), 0x80 => Opcode::ADD(OpcodeParameter::Register_Register(Register::A, Register::B)), 0x81 => Opcode::ADD(OpcodeParameter::Register_Register(Register::A, Register::C)), 0x82 => Opcode::ADD(OpcodeParameter::Register_Register(Register::A, Register::D)), 0x83 => Opcode::ADD(OpcodeParameter::Register_Register(Register::A, Register::E)), 0x84 => Opcode::ADD(OpcodeParameter::Register_Register(Register::A, Register::H)), 0x85 => Opcode::ADD(OpcodeParameter::Register_Register(Register::A, Register::L)), 0x86 => Opcode::ADD(OpcodeParameter::Register_Register(Register::A, Register::HL)), 0xC6 => Opcode::ADD(OpcodeParameter::Register_U8(Register::A, params.1)), 0x8F => Opcode::ADC(OpcodeParameter::Register_Register(Register::A, Register::A)), 0x88 => Opcode::ADC(OpcodeParameter::Register_Register(Register::A, Register::B)), 0x89 => Opcode::ADC(OpcodeParameter::Register_Register(Register::A, Register::C)), 0x8A => Opcode::ADC(OpcodeParameter::Register_Register(Register::A, Register::D)), 0x8B => Opcode::ADC(OpcodeParameter::Register_Register(Register::A, Register::E)), 0x8C => Opcode::ADC(OpcodeParameter::Register_Register(Register::A, Register::H)), 0x8D => Opcode::ADC(OpcodeParameter::Register_Register(Register::A, Register::L)), 0x8E => Opcode::ADC(OpcodeParameter::Register_Register(Register::A, Register::HL)), 0xCE => Opcode::ADC(OpcodeParameter::Register_U8(Register::A, params.1)), 0x97 => Opcode::SUB(OpcodeParameter::Register_Register(Register::A, Register::A)), 0x90 => Opcode::SUB(OpcodeParameter::Register_Register(Register::A, Register::B)), 0x91 => Opcode::SUB(OpcodeParameter::Register_Register(Register::A, Register::C)), 0x92 => Opcode::SUB(OpcodeParameter::Register_Register(Register::A, Register::D)), 0x93 => Opcode::SUB(OpcodeParameter::Register_Register(Register::A, Register::E)), 0x94 => Opcode::SUB(OpcodeParameter::Register_Register(Register::A, Register::H)), 0x95 => Opcode::SUB(OpcodeParameter::Register_Register(Register::A, Register::L)), 0x96 => Opcode::SUB(OpcodeParameter::Register_Register(Register::A, Register::HL)), 0xD6 => Opcode::SUB(OpcodeParameter::Register_U8(Register::A, params.1)), 0x9F => Opcode::SBC(OpcodeParameter::Register_Register(Register::A, Register::A)), 0x98 => Opcode::SBC(OpcodeParameter::Register_Register(Register::A, Register::B)), 0x99 => Opcode::SBC(OpcodeParameter::Register_Register(Register::A, Register::C)), 0x9A => Opcode::SBC(OpcodeParameter::Register_Register(Register::A, Register::D)), 0x9B => Opcode::SBC(OpcodeParameter::Register_Register(Register::A, Register::E)), 0x9C => Opcode::SBC(OpcodeParameter::Register_Register(Register::A, Register::H)), 0x9D => Opcode::SBC(OpcodeParameter::Register_Register(Register::A, Register::L)), 0x9E => Opcode::SBC(OpcodeParameter::Register_Register(Register::A, Register::HL)), 0xDE => Opcode::SBC(OpcodeParameter::Register_U8(Register::A, params.1)), 0xA7 => Opcode::AND(OpcodeParameter::Register_Register(Register::A, Register::A)), 0xA0 => Opcode::AND(OpcodeParameter::Register_Register(Register::A, Register::B)), 0xA1 => Opcode::AND(OpcodeParameter::Register_Register(Register::A, Register::C)), 0xA2 => Opcode::AND(OpcodeParameter::Register_Register(Register::A, Register::D)), 0xA3 => Opcode::AND(OpcodeParameter::Register_Register(Register::A, Register::E)), 0xA4 => Opcode::AND(OpcodeParameter::Register_Register(Register::A, Register::H)), 0xA5 => Opcode::AND(OpcodeParameter::Register_Register(Register::A, Register::L)), 0xA6 => Opcode::AND(OpcodeParameter::Register_Register(Register::A, Register::HL)), 0xE6 => Opcode::AND(OpcodeParameter::Register_U8(Register::A, params.1)), 0xB7 => Opcode::OR(OpcodeParameter::Register_Register(Register::A, Register::A)), 0xB0 => Opcode::OR(OpcodeParameter::Register_Register(Register::A, Register::B)), 0xB1 => Opcode::OR(OpcodeParameter::Register_Register(Register::A, Register::C)), 0xB2 => Opcode::OR(OpcodeParameter::Register_Register(Register::A, Register::D)), 0xB3 => Opcode::OR(OpcodeParameter::Register_Register(Register::A, Register::E)), 0xB4 => Opcode::OR(OpcodeParameter::Register_Register(Register::A, Register::H)), 0xB5 => Opcode::OR(OpcodeParameter::Register_Register(Register::A, Register::L)), 0xB6 => Opcode::OR(OpcodeParameter::Register_Register(Register::A, Register::HL)), 0xF6 => Opcode::OR(OpcodeParameter::Register_U8(Register::A, params.1)), 0xAF => Opcode::XOR(OpcodeParameter::Register_Register(Register::A, Register::A)), 0xA8 => Opcode::XOR(OpcodeParameter::Register_Register(Register::A, Register::B)), 0xA9 => Opcode::XOR(OpcodeParameter::Register_Register(Register::A, Register::C)), 0xAA => Opcode::XOR(OpcodeParameter::Register_Register(Register::A, Register::D)), 0xAB => Opcode::XOR(OpcodeParameter::Register_Register(Register::A, Register::E)), 0xAC => Opcode::XOR(OpcodeParameter::Register_Register(Register::A, Register::H)), 0xAD => Opcode::XOR(OpcodeParameter::Register_Register(Register::A, Register::L)), 0xAE => Opcode::XOR(OpcodeParameter::Register_Register(Register::A, Register::HL)), 0xEE => Opcode::XOR(OpcodeParameter::Register_U8(Register::A, params.1)), 0xBF => Opcode::CP(OpcodeParameter::Register_Register(Register::A, Register::A)), 0xB8 => Opcode::CP(OpcodeParameter::Register_Register(Register::A, Register::B)), 0xB9 => Opcode::CP(OpcodeParameter::Register_Register(Register::A, Register::C)), 0xBA => Opcode::CP(OpcodeParameter::Register_Register(Register::A, Register::D)), 0xBB => Opcode::CP(OpcodeParameter::Register_Register(Register::A, Register::E)), 0xBC => Opcode::CP(OpcodeParameter::Register_Register(Register::A, Register::H)), 0xBD => Opcode::CP(OpcodeParameter::Register_Register(Register::A, Register::L)), 0xBE => Opcode::CP(OpcodeParameter::Register_Register(Register::A, Register::HL)), 0xFE => Opcode::CP(OpcodeParameter::Register_U8(Register::A, params.1)), 0x3C => Opcode::INC(true, Register::A), 0x04 => Opcode::INC(true, Register::B), 0x0C => Opcode::INC(true, Register::C), 0x14 => Opcode::INC(true, Register::D), 0x1C => Opcode::INC(true, Register::E), 0x24 => Opcode::INC(true, Register::H), 0x2C => Opcode::INC(true, Register::L), 0x34 => Opcode::INC(true, Register::HL), 0x03 => Opcode::INC(false, Register::BC), 0x13 => Opcode::INC(false, Register::DE), 0x23 => Opcode::INC(false, Register::HL), 0x33 => Opcode::INC(false, Register::SP), 0x3D => Opcode::DEC(true, Register::A), 0x05 => Opcode::DEC(true, Register::B), 0x0D => Opcode::DEC(true, Register::C), 0x15 => Opcode::DEC(true, Register::D), 0x1D => Opcode::DEC(true, Register::E), 0x25 => Opcode::DEC(true, Register::H), 0x2D => Opcode::DEC(true, Register::L), 0x35 => Opcode::DEC(true, Register::HL), 0x0B => Opcode::DEC(false, Register::BC), 0x1B => Opcode::DEC(false, Register::DE), 0x2B => Opcode::DEC(false, Register::HL), 0x3B => Opcode::DEC(false, Register::SP), 0x09 => Opcode::ADD(OpcodeParameter::Register_Register(Register::HL, Register::BC)), 0x19 => Opcode::ADD(OpcodeParameter::Register_Register(Register::HL, Register::DE)), 0x29 => Opcode::ADD(OpcodeParameter::Register_Register(Register::HL, Register::HL)), 0x39 => Opcode::ADD(OpcodeParameter::Register_Register(Register::HL, Register::SP)), 0xE8 => Opcode::ADD(OpcodeParameter::Register_I8(Register::HL, params.1)), 0x27 => Opcode::DAA, 0x2F => Opcode::CPL, 0x3F => Opcode::CCF, 0x37 => Opcode::SCF, 0x17 => Opcode::RLA, 0x07 => Opcode::RLCA, 0x0F => Opcode::RRCA, 0x1F => Opcode::RRA, 0xCB => Opcode::PrefixCB, //0xCB => Opcode::SWAP, //0xCB => Opcode::RLC, //0xCB => Opcode::RL, //0xCB => Opcode::RRC, //0xCB => Opcode::RR, //0xCB => Opcode::SLA, //0xCB => Opcode::SRA, //0xCB => Opcode::SRL, //0xCB => Opcode::BIT, //0xCB => Opcode::SET, //0xCB => Opcode::RES, 0xC3 => Opcode::JP(OpcodeParameter::U16(two_byte_param)), 0xC2 => Opcode::JP(OpcodeParameter::FlagRegisterReset_U16(FlagRegister::Zero, two_byte_param)), 0xCA => Opcode::JP(OpcodeParameter::FlagRegisterSet_U16(FlagRegister::Zero, two_byte_param)), 0xD2 => Opcode::JP(OpcodeParameter::FlagRegisterReset_U16(FlagRegister::Carry, two_byte_param)), 0xDA => Opcode::JP(OpcodeParameter::FlagRegisterSet_U16(FlagRegister::Carry, two_byte_param)), 0xE9 => Opcode::JP(OpcodeParameter::Register(Register::HL)), 0x18 => Opcode::JR(OpcodeParameter::I8(params.1 as i8)), 0x20 => Opcode::JR(OpcodeParameter::FlagRegisterReset_I8(FlagRegister::Zero, params.1 as i8)), 0x28 => Opcode::JR(OpcodeParameter::FlagRegisterSet_I8(FlagRegister::Zero, params.1 as i8)), 0x30 => Opcode::JR(OpcodeParameter::FlagRegisterReset_I8(FlagRegister::Carry, params.1 as i8)), 0x38 => Opcode::JR(OpcodeParameter::FlagRegisterSet_I8(FlagRegister::Carry, params.1 as i8)), 0xCD => Opcode::CALL(OpcodeParameter::U16(two_byte_param)), 0xC4 => Opcode::CALL(OpcodeParameter::FlagRegisterReset_U16(FlagRegister::Zero, two_byte_param)), 0xCC => Opcode::CALL(OpcodeParameter::FlagRegisterSet_U16(FlagRegister::Zero, two_byte_param)), 0xD4 => Opcode::CALL(OpcodeParameter::FlagRegisterReset_U16(FlagRegister::Carry, two_byte_param)), 0xDC => Opcode::CALL(OpcodeParameter::FlagRegisterSet_U16(FlagRegister::Carry, two_byte_param)), 0xC7 => Opcode::RST(0x00), 0xCF => Opcode::RST(0x08), 0xD7 => Opcode::RST(0x10), 0xDF => Opcode::RST(0x18), 0xE7 => Opcode::RST(0x20), 0xEF => Opcode::RST(0x28), 0xF7 => Opcode::RST(0x30), 0xFF => Opcode::RST(0x38), 0xC9 => Opcode::RET(OpcodeParameter::NoParam), 0xC0 => Opcode::RET(OpcodeParameter::FlagRegisterReset(FlagRegister::Zero)), 0xC8 => Opcode::RET(OpcodeParameter::FlagRegisterSet(FlagRegister::Zero)), 0xD0 => Opcode::RET(OpcodeParameter::FlagRegisterReset(FlagRegister::Carry)), 0xD8 => Opcode::RET(OpcodeParameter::FlagRegisterSet(FlagRegister::Carry)), 0xD9 => Opcode::RETI, 0xF3 => Opcode::DI, 0xFB => Opcode::EI, 0x76 => Opcode::HALT, 0x10 => Opcode::STOP, 0x00 => Opcode::NOP, _ => Opcode::IllegalInstruction, } } } #[cfg(test)] mod tests { use super::*; #[test] fn test_registers_setters_getters() { // Test 8 bit setters and getters let mut registers = Registers::new(); registers.set(Register::A, 0b01010101); assert_eq!(registers.get(Register::A), 0b01010101); registers.set(Register::F, 0b01010101); assert_eq!(registers.get(Register::F), 0b01010101); registers.set(Register::B, 0b01010101); assert_eq!(registers.get(Register::B), 0b01010101); registers.set(Register::C, 0b01010101); assert_eq!(registers.get(Register::C), 0b01010101); registers.set(Register::D, 0b01010101); assert_eq!(registers.get(Register::D), 0b01010101); registers.set(Register::E, 0b01010101); assert_eq!(registers.get(Register::E), 0b01010101); registers.set(Register::H, 0b01010101); assert_eq!(registers.get(Register::H), 0b01010101); registers.set(Register::L, 0b01010101); assert_eq!(registers.get(Register::L), 0b01010101); // Test 16 bit setters and getters let mut registers = Registers::new(); registers.set(Register::A, 0b01010101); registers.set(Register::F, 0b11111111); assert_eq!(registers.get(Register::AF), 0b0101010111111111); registers.set(Register::AF, 0b1111111101010101); assert_eq!(registers.get(Register::AF), 0b1111111101010101); registers.set(Register::B, 0b01010101); registers.set(Register::C, 0b11111111); assert_eq!(registers.get(Register::BC), 0b0101010111111111); registers.set(Register::BC, 0b1111111101010101); assert_eq!(registers.get(Register::BC), 0b1111111101010101); registers.set(Register::D, 0b01010101); registers.set(Register::E, 0b11111111); assert_eq!(registers.get(Register::DE), 0b0101010111111111); registers.set(Register::DE, 0b1111111101010101); assert_eq!(registers.get(Register::DE), 0b1111111101010101); registers.set(Register::H, 0b01010101); registers.set(Register::L, 0b11111111); assert_eq!(registers.get(Register::HL), 0b0101010111111111); registers.set(Register::HL, 0b1111111101010101); assert_eq!(registers.get(Register::HL), 0b1111111101010101); registers.set(Register::SP, 0b0101010111111111); assert_eq!(registers.get(Register::SP), 0b0101010111111111); registers.set(Register::PC, 0b0101010111111111); assert_eq!(registers.get(Register::PC), 0b0101010111111111); } #[test] fn test_cpu_instructions() { // LD let mut bus = Bus::new(); let mut cpu = CPU::new(); cpu.registers.set(Register::A, 0xFF); cpu.exec(Opcode::LD(OpcodeParameter::Register_Register(Register::B, Register::A)), &mut bus); assert_eq!(cpu.registers.get(Register::B), 0xFF); assert_eq!(cpu.registers.get(Register::PC), 0x101); let mut cpu = CPU::new(); let mut bus = Bus::new(); cpu.exec(Opcode::LD(OpcodeParameter::Register_U16(Register::SP, 0xF1F1)), &mut bus); assert_eq!(cpu.registers.get(Register::SP), 0xF1F1); assert_eq!(cpu.registers.get(Register::PC), 0x103); let mut cpu = CPU::new(); let mut bus = Bus::new(); cpu.exec(Opcode::LD(OpcodeParameter::Register_U8(Register::B, 0xF1)), &mut bus); assert_eq!(cpu.registers.get(Register::B), 0xF1); assert_eq!(cpu.registers.get(Register::PC), 0x102); let mut cpu = CPU::new(); let mut bus = Bus::new(); cpu.registers.set(Register::SP, 0x1234); cpu.exec(Opcode::LD(OpcodeParameter::U16_Register(0xF0F0, Register::SP)), &mut bus); assert_eq!(bus.read_16bit(0xF0F0), 0x1234); assert_eq!(cpu.registers.get(Register::PC), 0x103); let mut cpu = CPU::new(); let mut bus = Bus::new(); let addr = 0xC000; cpu.registers.set(Register::A, 0xFF); cpu.registers.set(Register::HL, addr); bus.write(addr, 0x00); cpu.exec(Opcode::LD(OpcodeParameter::Register_Register(Register::HL, Register::A)), &mut bus); assert_eq!(bus.read(addr), 0xFF); assert_eq!(cpu.registers.get(Register::PC), 0x101); let mut cpu = CPU::new(); let mut bus = Bus::new(); let addr = 0xC000; cpu.registers.set(Register::A, 0x00); cpu.registers.set(Register::HL, addr); bus.write(addr, 0xFF); cpu.exec(Opcode::LD(OpcodeParameter::Register_Register(Register::A, Register::HL)), &mut bus); assert_eq!(cpu.registers.get(Register::A), 0xFF); assert_eq!(cpu.registers.get(Register::PC), 0x101); let mut cpu = CPU::new(); let mut bus = Bus::new(); let addr = 0xFF00; cpu.registers.set(Register::A, 0xF1); cpu.exec(Opcode::LD(OpcodeParameter::FF00plusU8_Register(4, Register::A)), &mut bus); assert_eq!(bus.read(addr + 4), 0xF1); assert_eq!(cpu.registers.get(Register::PC), 0x102); let mut cpu = CPU::new(); let mut bus = Bus::new(); let addr = 0xFF00; cpu.registers.set(Register::A, 0x00); bus.write(addr + 4, 0xF1); cpu.exec(Opcode::LD(OpcodeParameter::Register_FF00plusU8(Register::A, 4)), &mut bus); assert_eq!(cpu.registers.get(Register::A), 0xF1); assert_eq!(cpu.registers.get(Register::PC), 0x102); // LDI let mut bus = Bus::new(); let mut cpu = CPU::new(); let addr = 0xC000; cpu.registers.set(Register::A, 0x00); cpu.registers.set(Register::HL, addr); bus.write(addr, 0xF1); cpu.exec(Opcode::LDI(OpcodeParameter::Register_RegisterIncrement(Register::A, Register::HL)), &mut bus); assert_eq!(bus.read(addr), 0xF1); assert_eq!(cpu.registers.get(Register::A), 0xF1); assert_eq!(cpu.registers.get(Register::HL), addr + 1); assert_eq!(cpu.registers.get(Register::PC), 0x101); // JP let mut cpu = CPU::new(); let mut bus = Bus::new(); cpu.exec(Opcode::JP(OpcodeParameter::U16(0x1F1F)), &mut bus); assert_eq!(cpu.registers.get(Register::PC), 0x1F1F); // JR let mut cpu = CPU::new(); let mut bus = Bus::new(); cpu.registers.set(Register::PC, 100); cpu.exec(Opcode::JR(OpcodeParameter::I8(-5)), &mut bus); assert_eq!(cpu.registers.get(Register::PC), 95 + 2); cpu.registers.set(Register::PC, 100); cpu.exec(Opcode::JR(OpcodeParameter::I8(5)), &mut bus); assert_eq!(cpu.registers.get(Register::PC), 105 + 2); cpu.registers.set(Register::PC, 100); cpu.registers.set_flag(FlagRegister::Zero, false); cpu.exec(Opcode::JR(OpcodeParameter::FlagRegisterReset_I8(FlagRegister::Zero, -5)), &mut bus); assert_eq!(cpu.registers.get(Register::PC), 95 + 2); cpu.registers.set(Register::PC, 100); cpu.registers.set_flag(FlagRegister::Zero, true); cpu.exec(Opcode::JR(OpcodeParameter::FlagRegisterSet_I8(FlagRegister::Zero, -5)), &mut bus); assert_eq!(cpu.registers.get(Register::PC), 95 + 2); cpu.registers.set(Register::PC, 100); cpu.registers.set_flag(FlagRegister::Zero, true); cpu.exec(Opcode::JR(OpcodeParameter::FlagRegisterReset_I8(FlagRegister::Zero, -5)), &mut bus); assert_eq!(cpu.registers.get(Register::PC), 100 + 2); cpu.registers.set(Register::PC, 100); cpu.registers.set_flag(FlagRegister::Zero, false); cpu.exec(Opcode::JR(OpcodeParameter::FlagRegisterSet_I8(FlagRegister::Zero, -5)), &mut bus); assert_eq!(cpu.registers.get(Register::PC), 100 + 2); cpu.registers.set(Register::PC, 100); cpu.registers.set_flag(FlagRegister::Zero, false); cpu.exec(Opcode::JR(OpcodeParameter::FlagRegisterReset_I8(FlagRegister::Zero, 5)), &mut bus); assert_eq!(cpu.registers.get(Register::PC), 105 + 2); // DI let mut cpu = CPU::new(); let mut bus = Bus::new(); cpu.exec(Opcode::DI, &mut bus); assert_eq!(bus.read(0xFFFF), 0x00); assert_eq!(cpu.registers.get(Register::PC), 0x101); // RLCA let mut cpu = CPU::new(); let mut bus = Bus::new(); cpu.registers.set_flag(FlagRegister::Carry, false); cpu.registers.set(Register::A, 0b00000010); cpu.exec(Opcode::RLCA, &mut bus); assert_eq!(cpu.registers.get(Register::A), 0b00000010); assert_eq!(cpu.registers.get_flag(FlagRegister::Carry), false); assert_eq!(cpu.registers.get(Register::PC), 0x101); let mut cpu = CPU::new(); cpu.registers.set_flag(FlagRegister::Carry, false); cpu.registers.set(Register::A, 0b00000001); cpu.exec(Opcode::RLCA, &mut bus); assert_eq!(cpu.registers.get(Register::A), 0b00000001); assert_eq!(cpu.registers.get_flag(FlagRegister::Carry), true); assert_eq!(cpu.registers.get(Register::PC), 0x101); // RRCA let mut cpu = CPU::new(); cpu.registers.set(Register::A, 0b01000000); cpu.registers.set_flag(FlagRegister::Carry, false); cpu.exec(Opcode::RRCA, &mut bus); assert_eq!(cpu.registers.get(Register::A), 0b01000000); assert_eq!(cpu.registers.get_flag(FlagRegister::Carry), false); assert_eq!(cpu.registers.get(Register::PC), 0x101); let mut cpu = CPU::new(); cpu.registers.set_flag(FlagRegister::Carry, false); cpu.registers.set(Register::A, 0b10000000); cpu.exec(Opcode::RRCA, &mut bus); assert_eq!(cpu.registers.get(Register::A), 0b10000000); assert_eq!(cpu.registers.get_flag(FlagRegister::Carry), true); assert_eq!(cpu.registers.get(Register::PC), 0x101); // CALL let mut cpu = CPU::new(); let sp = 0xFFDF; cpu.registers.set(Register::SP, sp); cpu.registers.set(Register::PC, 0x1234); cpu.exec(Opcode::CALL(OpcodeParameter::U16(0xF0F0)), &mut bus); assert_eq!(bus.read_16bit(sp - 2), 0x1234); assert_eq!(cpu.registers.get(Register::SP), sp - 2); assert_eq!(cpu.registers.get(Register::PC), 0xF0F0); // RST let mut cpu = CPU::new(); let sp = 0xFFDF; cpu.registers.set(Register::SP, sp); cpu.registers.set(Register::PC, 0x1234); cpu.exec(Opcode::RST(0xF0), &mut bus); assert_eq!(bus.read_16bit(sp - 2), 0x1234); assert_eq!(cpu.registers.get(Register::SP), sp - 2); assert_eq!(cpu.registers.get(Register::PC), 0x00F0); // POP let mut cpu = CPU::new(); let sp = 0xFFDF; cpu.registers.set(Register::SP, sp); bus.write_16bit(sp, 0x1234); cpu.exec(Opcode::POP(Register::HL), &mut bus); assert_eq!(cpu.registers.get(Register::HL), 0x1234); assert_eq!(cpu.registers.get(Register::SP), sp + 2); // RET let mut cpu = CPU::new(); let sp = 0xFFDF; cpu.registers.set(Register::SP, sp); bus.write_16bit(sp, 0x1234); cpu.exec(Opcode::RET(OpcodeParameter::NoParam), &mut bus); assert_eq!(cpu.registers.get(Register::PC), 0x1234); assert_eq!(cpu.registers.get(Register::SP), sp + 2); // INC let mut cpu = CPU::new(); cpu.registers.set(Register::A, 0); cpu.exec(Opcode::INC(true, Register::A), &mut bus); assert_eq!(cpu.registers.get_flag(FlagRegister::Zero), false); assert_eq!(cpu.registers.get_flag(FlagRegister::Substract), false); assert_eq!(cpu.registers.get_flag(FlagRegister::HalfCarry), false); assert_eq!(cpu.registers.get(Register::PC), 0x101); let mut cpu = CPU::new(); cpu.registers.set(Register::A, 0b00001111); cpu.exec(Opcode::INC(true, Register::A), &mut bus); assert_eq!(cpu.registers.get_flag(FlagRegister::Zero), false); assert_eq!(cpu.registers.get_flag(FlagRegister::Substract), false); assert_eq!(cpu.registers.get_flag(FlagRegister::HalfCarry), true); assert_eq!(cpu.registers.get(Register::PC), 0x101); let mut cpu = CPU::new(); cpu.registers.set(Register::HL, 0b0000111111111111); cpu.exec(Opcode::INC(true, Register::HL), &mut bus); assert_eq!(cpu.registers.get_flag(FlagRegister::Zero), false); assert_eq!(cpu.registers.get_flag(FlagRegister::Substract), false); assert_eq!(cpu.registers.get_flag(FlagRegister::HalfCarry), true); assert_eq!(cpu.registers.get(Register::HL), 0b0001000000000000); assert_eq!(cpu.registers.get(Register::PC), 0x101); // DEC let mut cpu = CPU::new(); cpu.registers.set(Register::A, 1); cpu.exec(Opcode::DEC(true, Register::A), &mut bus); assert_eq!(cpu.registers.get_flag(FlagRegister::Zero), true); assert_eq!(cpu.registers.get_flag(FlagRegister::Substract), true); assert_eq!(cpu.registers.get_flag(FlagRegister::HalfCarry), false); assert_eq!(cpu.registers.get(Register::A), 0); assert_eq!(cpu.registers.get(Register::PC), 0x101); let mut cpu = CPU::new(); cpu.registers.set(Register::A, 0b00010000); cpu.exec(Opcode::DEC(true, Register::A), &mut bus); assert_eq!(cpu.registers.get_flag(FlagRegister::Zero), false); assert_eq!(cpu.registers.get_flag(FlagRegister::Substract), true); assert_eq!(cpu.registers.get_flag(FlagRegister::HalfCarry), true); assert_eq!(cpu.registers.get(Register::A), 0b00001111); assert_eq!(cpu.registers.get(Register::PC), 0x101); let mut cpu = CPU::new(); cpu.registers.set(Register::HL, 0b0001000000000000); cpu.exec(Opcode::DEC(true, Register::HL), &mut bus); assert_eq!(cpu.registers.get_flag(FlagRegister::Zero), false); assert_eq!(cpu.registers.get_flag(FlagRegister::Substract), true); assert_eq!(cpu.registers.get_flag(FlagRegister::HalfCarry), true); assert_eq!(cpu.registers.get(Register::HL), 0b0000111111111111); assert_eq!(cpu.registers.get(Register::PC), 0x101); // NOP let mut cpu = CPU::new(); let mut bus = Bus::new(); cpu.exec(Opcode::NOP, &mut bus); assert_eq!(cpu.registers.get(Register::PC), 0x101); } }