diff --git a/snes-core/src/cpu/instructionstemp/lsr.rs b/snes-core/src/cpu/instructionstemp/lsr.rs new file mode 100644 index 0000000..4353e5a --- /dev/null +++ b/snes-core/src/cpu/instructionstemp/lsr.rs @@ -0,0 +1,131 @@ +use crate::{cpu::{bus::Bus, registers::Registers}, utils::{alu, addressing::AddressingMode}}; + +use crate::cpu::cycles; +use super::{CPUInstruction, Decode, read_8bit_from_address, write_8bit_to_address, read_16bit_from_address, write_16bit_to_address}; +use super::decoder_common; + +static INSTR_NAME: &'static str = "LSR"; + +pub struct LSR8 { + addressing_mode: AddressingMode, +} + +impl CPUInstruction for LSR8 { + fn execute(&self, registers: &mut Registers, bus: &mut Bus) { + let (result, affected_flags) = alu::lsr(read_8bit_from_address(registers, bus, self.addressing_mode)); + write_8bit_to_address(registers, bus, self.addressing_mode, result); + registers.set_flags(&affected_flags); + let (bytes, cycles) = cycles::increment_cycles_shift(®isters, self.addressing_mode); + registers.increment_pc(bytes); registers.cycles += cycles; + } +} + +impl Decode for LSR8 { + fn mnemonic(&self, registers: &Registers, bus: &Bus, opcode: u8) -> String { + decoder_common::mnemonic_arithmetic(false, opcode, INSTR_NAME, self.addressing_mode, registers, bus) + } +} + +pub struct LSR16 { + addressing_mode: AddressingMode, +} + +impl CPUInstruction for LSR16 { + fn execute(&self, registers: &mut Registers, bus: &mut Bus) { + let (result, affected_flags) = alu::lsr(read_16bit_from_address(registers, bus, self.addressing_mode)); + write_16bit_to_address(registers, bus, self.addressing_mode, result); + registers.set_flags(&affected_flags); + let (bytes, cycles) = cycles::increment_cycles_shift(®isters, self.addressing_mode); + registers.increment_pc(bytes); registers.cycles += cycles; + } +} + +impl Decode for LSR16 { + fn mnemonic(&self, registers: &Registers, bus: &Bus, opcode: u8) -> String { + decoder_common::mnemonic_arithmetic(true, opcode, INSTR_NAME, self.addressing_mode, registers, bus) + } +} + + +#[cfg(test)] +mod cpu_instructions_tests { + use super::*; + + #[test] + fn test_8bit() { + let mut registers = Registers::new(); + let mut bus = Bus::new(); + registers.emulation_mode = false; + registers.a = 0b00000000_00000011; + registers.pbr = 0x00; + registers.pc = 0x0000; + registers.set_16bit_mode(false); + registers.set_negative_flag(true); + registers.set_carry_flag(false); + let instruction = LSR8{addressing_mode: AddressingMode::Accumulator}; + instruction.execute(&mut registers, &mut bus); + assert_eq!(registers.a, 0b00000000_00000001); + assert_eq!(registers.pc, 0x01); + assert_eq!(registers.cycles, 2); + assert!(registers.get_carry_flag()); + assert!(!registers.get_zero_flag()); + assert!(!registers.get_negative_flag()); + + let mut registers = Registers::new(); + let mut bus = Bus::new(); + registers.emulation_mode = false; + registers.a = 0b00000001_10000011; + registers.pbr = 0x00; + registers.pc = 0x0000; + registers.set_16bit_mode(false); + registers.set_negative_flag(true); + registers.set_carry_flag(false); + let instruction = LSR8{addressing_mode: AddressingMode::Accumulator}; + instruction.execute(&mut registers, &mut bus); + assert_eq!(registers.a, 0b00000001_01000001); + assert_eq!(registers.pc, 0x01); + assert_eq!(registers.cycles, 2); + assert!(registers.get_carry_flag()); + assert!(!registers.get_zero_flag()); + assert!(!registers.get_negative_flag()); + } + + #[test] + fn test_16bit() { + let mut registers = Registers::new(); + let mut bus = Bus::new(); + registers.emulation_mode = false; + registers.a = 0b00000000_00000011; + registers.pbr = 0x00; + registers.pc = 0x0000; + registers.set_16bit_mode(true); + registers.set_negative_flag(true); + registers.set_carry_flag(false); + let instruction = LSR16{addressing_mode: AddressingMode::Accumulator}; + instruction.execute(&mut registers, &mut bus); + assert_eq!(registers.a, 0b00000000_00000001); + assert_eq!(registers.pc, 0x01); + assert_eq!(registers.cycles, 4); + assert!(registers.get_carry_flag()); + assert!(!registers.get_zero_flag()); + assert!(!registers.get_negative_flag()); + + let mut registers = Registers::new(); + let mut bus = Bus::new(); + registers.emulation_mode = false; + registers.a = 0b10000000_00000011; + registers.pbr = 0x00; + registers.pc = 0x0000; + registers.set_16bit_mode(true); + registers.set_negative_flag(true); + registers.set_carry_flag(true); + let instruction = LSR16{addressing_mode: AddressingMode::Accumulator}; + instruction.execute(&mut registers, &mut bus); + assert_eq!(registers.a, 0b01000000_00000001); + assert_eq!(registers.pc, 0x01); + assert_eq!(registers.cycles, 4); + assert!(registers.get_carry_flag()); + assert!(!registers.get_zero_flag()); + assert!(!registers.get_negative_flag()); + } +} diff --git a/snes-core/src/cpu/instructionstemp/mod.rs b/snes-core/src/cpu/instructionstemp/mod.rs index 80f7081..4bf1d7f 100644 --- a/snes-core/src/cpu/instructionstemp/mod.rs +++ b/snes-core/src/cpu/instructionstemp/mod.rs @@ -37,6 +37,7 @@ pub mod jsr; pub mod lda; pub mod ldx; pub mod ldy; +pub mod lsr; pub mod bit_common; pub mod dec_common; pub mod decoder_common;