diff options
Diffstat (limited to 'src/mos6502.rs')
| -rw-r--r-- | src/mos6502.rs | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/src/mos6502.rs b/src/mos6502.rs index f279a2a..9428171 100644 --- a/src/mos6502.rs +++ b/src/mos6502.rs @@ -3,6 +3,8 @@ use memory::{CPUMemory, VMem}; pub const CPU_FREQ: u32 = 1789773; + +#[macro_export] macro_rules! make_optable { ($x:ident, $t: ty) => (pub const $x: [$t; 0x100] = [ /* 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf */ @@ -25,6 +27,7 @@ macro_rules! make_optable { ];); } +#[macro_export] macro_rules! make_addrtable { ($x:ident, $t: ty) => (pub const $x: [$t; 0x100] = [ nil, xin, nil, xin, zpg, zpg, zpg, zpg, nil, imm, acc, imm, abs, abs, abs, abs, @@ -564,13 +567,13 @@ mod addr { } fn xin(cpu: &mut CPU) -> u8 { - cpu.ea = read16wrap!(cpu.mem, - cpu.mem.read(cpu.opr) - .wrapping_add(cpu.x) as u16) as u16; 0 + let addr = cpu.mem.read(cpu.opr).wrapping_add(cpu.x) as u16; + cpu.ea = read16wrap!(cpu.mem, addr) as u16; 0 } fn iny(cpu: &mut CPU) -> u8 { - let base = read16wrap!(cpu.mem, cpu.mem.read(cpu.opr) as u16); + let addr = cpu.mem.read(cpu.opr) as u16; + let base = read16wrap!(cpu.mem, addr); let sum = (base & 0xff) + (cpu.y as u16); cpu.ea = (base & 0xff00).wrapping_add(sum); (sum >> 8) as u8 /* boundary cross if carry */ @@ -609,13 +612,13 @@ macro_rules! make_int { fn $f(&mut self) { let pc = self.pc; let sp = self.sp; + self.cycle += 7; self.mem.write(stack_addr!(sp, 0), (pc >> 8) as u8); self.mem.write(stack_addr!(sp, 1), pc as u8); self.mem.write(stack_addr!(sp, 2), self.status); self.sp = sp.wrapping_sub(3); self.pc = read16!(self.mem, $v as u16); self.status |= INT_FLAG; - self.cycle += 7; }); } @@ -627,7 +630,7 @@ impl<'a> CPU<'a> { #[inline(always)] pub fn get_neg(&self) -> u8 { (self.status >> 7) & 1 } pub fn new(mem: CPUMemory<'a>) -> Self { - let pc = read16!(mem, RESET_VECTOR as u16); + let pc = 0; /* nes power up state */ let a = 0; let x = 0; @@ -644,6 +647,11 @@ impl<'a> CPU<'a> { mem} } + pub fn start(&mut self) { + self.cycle = 2; + self.pc = read16!(self.mem, RESET_VECTOR as u16); + } + make_int!(nmi, NMI_VECTOR); make_int!(irq, IRQ_VECTOR); @@ -657,9 +665,11 @@ impl<'a> CPU<'a> { _ => () } } + self.cycle += 1; let pc = self.pc; let opcode = self.mem.read(pc) as usize; /* + use disasm; let len = INST_LENGTH[opcode]; let mut code = vec![0; len as usize]; for i in 0..len as u16 { @@ -675,10 +685,10 @@ impl<'a> CPU<'a> { 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]; + self.cycle += INST_CYCLE[opcode] as u32 - 1; + self.cycle += (addr::ADDR_MODES[opcode](self) * INST_EXTRA_CYCLE[opcode]) as u32; /* execute the inst */ ops::OPS[opcode](self); - self.cycle += (INST_CYCLE[opcode] + e) as u32; //(self.cycle - cycle0) as u8 } @@ -699,6 +709,11 @@ impl<'a> CPU<'a> { } #[inline(always)] + pub fn suppress_nmi(&mut self) { + self.int = None; + } + + #[inline(always)] pub fn trigger_delayed_nmi(&mut self) { self.int = Some(IntType::DelayedNMI); } |