lda

snes-core/src/cpu/instructionstemp/jsr.rs

@@ -74,6 +74,5 @@ mod cpu_instructions_tests {
         assert_eq!(registers.pc, 0xBBCC);
         assert_eq!(registers.sp, 0x1F9);
         assert_eq!(registers.cycles, 8);
-        assert!(false)
     }
 }

snes-core/src/cpu/instructionstemp/lda.rs

@@ -0,0 +1,103 @@
+use crate::common::flags::Flags;
+use crate::cpu::cycles;
+use crate::cpu::{bus::Bus, registers::Registers};
+use crate::utils::addressing::AddressingMode;
+
+use super::{CPUInstruction, Decode, read_8bit_from_address, bit_common, read_16bit_from_address};
+use super::decoder_common;
+
+static INSTR_NAME: &'static str = "LDA";
+
+pub struct LDA8 {
+    addressing_mode: AddressingMode,
+}
+
+impl CPUInstruction for LDA8 {
+    fn execute(&self, registers: &mut Registers, bus: &mut Bus) {
+        let value = read_8bit_from_address(registers, bus, self.addressing_mode);
+        registers.set_flags(&[
+            Flags::Negative(value >> 7 == 1),
+            Flags::Zero(value == 0),
+        ]);
+        registers.set_low_a(value);
+        bit_common::do_bit(registers, registers.a as u8, value, self.addressing_mode);
+        let (bytes, cycles) = cycles::increment_cycles_lda(&registers, self.addressing_mode);
+        registers.increment_pc(bytes); registers.cycles += cycles;
+    }
+}
+
+impl Decode for LDA8 {
+    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 LDA16 {
+    addressing_mode: AddressingMode,
+}
+
+impl CPUInstruction for LDA16 {
+    fn execute(&self, registers: &mut Registers, bus: &mut Bus) {
+        let value = read_16bit_from_address(registers, bus, self.addressing_mode);
+        registers.a = value;
+        registers.set_flags(&[
+            Flags::Negative(value >> 15 == 1),
+            Flags::Zero(value == 0),
+        ]);
+        let (bytes, cycles) = cycles::increment_cycles_lda(&registers, self.addressing_mode);
+        registers.increment_pc(bytes); registers.cycles += cycles;
+    }
+}
+
+impl Decode for LDA16 {
+    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.a  = 0x0000;
+        registers.pc  = 0x0000;
+        registers.pbr  = 0x00;
+        registers.set_negative_flag(false);
+        registers.set_zero_flag(true);
+        registers.set_16bit_mode(false);
+        bus.write(0x0001, 0xFF);
+        let instruction = LDA8{addressing_mode: AddressingMode::Immediate};
+        instruction.execute(&mut registers, &mut bus);
+        assert_eq!(registers.pc, 0x0002);
+        assert_eq!(registers.a, 0x00FF);
+        assert_eq!(registers.cycles, 2);
+        assert!(registers.get_negative_flag());
+        assert!(!registers.get_zero_flag());
+    }
+
+    #[test]
+    fn test_16bit() {
+        let mut registers = Registers::new();
+        let mut bus = Bus::new();
+        registers.a  = 0x0000;
+        registers.pc  = 0x0000;
+        registers.pbr  = 0x00;
+        registers.set_negative_flag(false);
+        registers.set_zero_flag(true);
+        registers.set_16bit_mode(true);
+        bus.write(0x0001, 0xFF);
+        bus.write(0x0002, 0xFF);
+        let instruction = LDA16{addressing_mode: AddressingMode::Immediate};
+        instruction.execute(&mut registers, &mut bus);
+        assert_eq!(registers.pc, 0x0002);
+        assert_eq!(registers.a, 0xFFFF);
+        assert_eq!(registers.cycles, 2);
+        assert!(registers.get_negative_flag());
+        assert!(!registers.get_zero_flag());
+    }
+}

snes-core/src/cpu/instructionstemp/mod.rs

@@ -34,6 +34,7 @@ pub mod inx;
 pub mod iny;
 pub mod jmp;
 pub mod jsr;
+pub mod lda;
 pub mod bit_common;
 pub mod dec_common;
 pub mod decoder_common;