diff options
Diffstat (limited to 'src/mos6502.rs')
| -rw-r--r-- | src/mos6502.rs | 59 |
1 files changed, 32 insertions, 27 deletions
diff --git a/src/mos6502.rs b/src/mos6502.rs index e95910f..9dd3d85 100644 --- a/src/mos6502.rs +++ b/src/mos6502.rs @@ -677,7 +677,8 @@ mod addr { enum IntType { NMI, - IRQ + IRQ, + DelayedNMI } pub struct CPU<'a> { @@ -746,35 +747,34 @@ impl<'a> CPU<'a> { //let cycle0 = self.cycle; if self.int.is_some() { match self.int { - Some(IntType::NMI) => self.nmi(), - Some(IntType::IRQ) => self.irq(), + Some(IntType::NMI) => {self.nmi(); self.int = None; return}, + Some(IntType::IRQ) => {self.irq(); self.int = None; return}, + Some(IntType::DelayedNMI) => self.trigger_nmi(), _ => () } - self.int = None; - } else { - let pc = self.pc; - let opcode = self.mem.read(pc) as usize; - /* - let len = INST_LENGTH[opcode]; - let mut code = vec![0; len as usize]; - for i in 0..len as u16 { - code[i as usize] = self.mem.read(pc + i); - } - println!("0x{:04x} {} a:{:02x} x:{:02x} y:{:02x} s: {:02x} sp: {:02x}", - pc, disasm::parse(opcode as u8, &code[1..]), - self.a, self.x, self.y, self.status, self.sp); - */ - /* update opr pointing to operands of current inst */ - self.opr = pc.wrapping_add(1); - /* update program counter pointing to next inst */ - self.pc = pc.wrapping_add(INST_LENGTH[opcode] as u16); - /* get effective address based on addressing mode */ - self.acc = false; - let e = addr::ADDR_MODES[opcode](self) * INST_EXTRA_CYCLE[opcode]; - /* execute the inst */ - ops::OPS[opcode](self); - self.cycle += (INST_CYCLE[opcode] + e) as u32; } + let pc = self.pc; + let opcode = self.mem.read(pc) as usize; + /* + let len = INST_LENGTH[opcode]; + let mut code = vec![0; len as usize]; + for i in 0..len as u16 { + code[i as usize] = self.mem.read(pc + i); + } + println!("0x{:04x} {} a:{:02x} x:{:02x} y:{:02x} s: {:02x} sp: {:02x}", + pc, disasm::parse(opcode as u8, &code[1..]), + self.a, self.x, self.y, self.status, self.sp); + */ + /* update opr pointing to operands of current inst */ + self.opr = pc.wrapping_add(1); + /* update program counter pointing to next inst */ + self.pc = pc.wrapping_add(INST_LENGTH[opcode] as u16); + /* get effective address based on addressing mode */ + self.acc = false; + let e = addr::ADDR_MODES[opcode](self) * INST_EXTRA_CYCLE[opcode]; + /* execute the inst */ + ops::OPS[opcode](self); + self.cycle += (INST_CYCLE[opcode] + e) as u32; //(self.cycle - cycle0) as u8 } @@ -795,6 +795,11 @@ impl<'a> CPU<'a> { } #[inline(always)] + pub fn trigger_delayed_nmi(&mut self) { + self.int = Some(IntType::DelayedNMI); + } + + #[inline(always)] pub fn trigger_irq(&mut self) { if self.get_int() == 0 { self.int = Some(match self.int { |