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-rw-r--r--src/apu.rs207
-rw-r--r--src/bin.rs13
-rw-r--r--src/memory.rs7
-rw-r--r--src/mos6502.rs17
4 files changed, 195 insertions, 49 deletions
diff --git a/src/apu.rs b/src/apu.rs
index 57525bf..5d264fb 100644
--- a/src/apu.rs
+++ b/src/apu.rs
@@ -9,6 +9,11 @@ pub trait Speaker {
const CPU_SAMPLE_FREQ: u32 = 240;
pub const AUDIO_SAMPLE_FREQ: u32 = 44100;
+const TRI_SEQ_TABLE: [u8; 32] = [
+ 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
+];
+
const LEN_TABLE: [u8; 32] = [
10, 254, 20, 2, 40, 4, 80, 6, 160, 8, 60, 10, 14, 12, 26, 14,
12, 16, 24, 18, 48, 20, 96, 22, 192, 24, 72, 26, 16, 28, 32, 30,
@@ -68,47 +73,48 @@ const TND_TABLE: [u16; 203] = [
];
struct Sampler {
- ticks_remain: u32,
- ticks_now: u32,
- ticks_unit: u32,
- ticks_all: u32,
- ticks_extra: u32,
- ticks_extra_all: u32,
+ freq2: u32,
+ q0: u32,
+ r0: u32,
+ ddl: (u32, u32),
+ cnt: u32,
+ sec_cnt: u32
}
impl Sampler {
fn new(freq1: u32, freq2: u32) -> Self {
- let unit = freq1 / freq2;
- let extra = freq1 - unit * freq2;
+ let q0 = freq1 / freq2;
+ let r0 = freq1 - q0 * freq2;
Sampler {
- ticks_remain: freq1 - extra,
- ticks_now: 0,
- ticks_unit: unit,
- ticks_all: freq1 - extra,
- ticks_extra: extra,
- ticks_extra_all: extra
+ freq2,
+ q0,
+ r0,
+ ddl: (q0, r0),
+ cnt: 0,
+ sec_cnt: 0
}
}
fn tick(&mut self) -> (bool, bool) {
- let unit = self.ticks_unit;
- if self.ticks_now == 0 {
- self.ticks_now = unit;
- self.ticks_remain -= unit;
- if self.ticks_remain == 0 {
- /* compensate to last exactly 1 sec */
- self.ticks_now += self.ticks_remain;
- /* reload for the next second */
- self.ticks_remain = self.ticks_all;
- self.ticks_extra = self.ticks_extra_all;
- }
- if self.ticks_extra > 0 {
- self.ticks_extra -= 1;
- self.ticks_now += 1;
+ let (q, r) = self.ddl;
+ if self.cnt == q {
+ let nr = r + self.r0;
+ self.ddl = if nr > self.freq2 {
+ (self.q0, nr - self.freq2)
+ } else {
+ (self.q0 - 1, nr)
+ };
+ self.cnt = 0;
+ self.sec_cnt += 1;
+ let sec = self.sec_cnt == self.freq2;
+ if sec {
+ self.sec_cnt = 0
}
+ (true, sec)
+ } else {
+ self.cnt += 1;
+ (false, false)
}
- self.ticks_now -= 1;
- (self.ticks_now == 0, self.ticks_remain == self.ticks_all)
}
}
@@ -169,16 +175,18 @@ impl Pulse {
let mut reload = self.swp_rld;
if self.swp_lvl == 0 {
reload = true;
- let p = self.timer_period;
- let mut delta = p >> self.swp_count;
- if self.swp_neg {
- delta = !delta;
- if self.comple { delta += 1; } /* two's complement */
- }
- p.wrapping_add(delta);
- self.muted = self.timer_period < 8 || (self.timer_period >> 11 != 0);
- if !self.muted && self.swp_en && self.swp_count != 0 {
- self.timer_period = p;
+ if self.swp_en {
+ let mut p = self.timer_period;
+ let mut delta = p >> self.swp_count;
+ if self.swp_neg {
+ delta = !delta;
+ if self.comple { delta += 1; } /* two's complement */
+ }
+ p = p.wrapping_add(delta);
+ self.muted = p < 8 || (p >> 11 != 0);
+ if !self.muted && self.swp_count != 0 {
+ self.timer_period = p;
+ }
}
} else {
self.swp_lvl -= 1;
@@ -274,15 +282,117 @@ impl Pulse {
Pulse {env_period: 0, env_lvl: 0, decay_lvl: 0,
env_start: false, env_loop: false, env_const: false, env_vol: 0,
swp_count: 0, swp_period: 0, swp_lvl: 0,
- swp_en: false, swp_neg: false, swp_rld: false, muted: true,
+ swp_en: false, swp_neg: false, swp_rld: false, muted: false,
len_lvl: 0, timer_period: 0, timer_lvl: 0,
seq_wave: 0, seq_cnt: 0, enabled: false, comple}
}
}
+pub struct Triangle {
+ /* linear counter */
+ cnt_rld: bool,
+ cnt_lvl: u8,
+ cnt_rld_val: u8,
+ /* length counter */
+ len_lvl: u8,
+ /* timer */
+ timer_period: u16,
+ timer_lvl: u16,
+ /* sequencer */
+ seq_cnt: u8,
+ enabled: bool,
+ /* misc */
+ ctrl: bool
+}
+
+impl Triangle {
+ fn tick_counter(&mut self) {
+ if self.cnt_rld {
+ self.cnt_lvl = self.cnt_rld_val
+ } else if self.cnt_lvl > 0 {
+ self.cnt_lvl -= 1
+ }
+ if !self.ctrl {
+ self.cnt_rld = false
+ }
+ }
+
+ fn tick_length(&mut self) {
+ if self.len_lvl > 0 && !self.ctrl {
+ self.len_lvl -= 1
+ }
+ }
+
+
+ fn tick_timer(&mut self) {
+ if self.len_lvl > 0 && self.cnt_lvl > 0 {
+ if self.timer_lvl == 0 {
+ self.timer_lvl = self.timer_period;
+ if self.seq_cnt == 31 {
+ self.seq_cnt = 0
+ } else {
+ self.seq_cnt += 1
+ }
+ } else {
+ self.timer_lvl -= 1
+ }
+ }
+ }
+
+ fn disable(&mut self) {
+ self.len_lvl = 0;
+ self.enabled = false;
+ }
+
+ fn enable(&mut self) { self.enabled = true }
+
+ fn new() -> Self {
+ Triangle {
+ cnt_rld: false, cnt_lvl: 0, cnt_rld_val: 0,
+ len_lvl: 0, timer_period: 0, timer_lvl: 0,
+ seq_cnt: 0, enabled: false, ctrl: false
+ }
+ }
+
+ fn get_len(&self) -> u8 { self.len_lvl }
+ fn set_cnt_lvl(&mut self, d: u8) { self.cnt_lvl = d }
+ fn set_ctrl(&mut self, b: bool) { self.ctrl = b }
+ fn set_cnt_rld_val(&mut self, d: u8) { self.cnt_rld_val = d }
+ fn set_timer_peroid(&mut self, p: u16) { self.timer_period = p }
+ fn set_len(&mut self, d: u8) {
+ if self.enabled {
+ self.len_lvl = LEN_TABLE[d as usize]
+ }
+ }
+
+ pub fn write_reg1(&mut self, data: u8) {
+ self.set_cnt_rld_val(data & 0x7f);
+ self.set_ctrl(data >> 7 == 1);
+ }
+
+ pub fn write_reg3(&mut self, data: u8) {
+ self.timer_period = (self.timer_period & 0xff00) | data as u16
+ }
+
+ pub fn write_reg4(&mut self, data: u8) {
+ self.set_len(data >> 3);
+ self.timer_period = (self.timer_period & 0x00ff) | ((data as u16 & 7) << 8);
+ self.seq_cnt = 0;
+ self.timer_lvl = self.timer_period;
+ self.cnt_rld = true;
+ }
+
+ fn output(&self) -> u8 {
+ let len = self.len_lvl > 0;
+ let lin = self.cnt_lvl > 0;
+ if len && lin { TRI_SEQ_TABLE[self.seq_cnt as usize] } else { 0 }
+ }
+}
+
pub struct APU<'a> {
pub pulse1: Pulse,
pub pulse2: Pulse,
+ pub triangle: Triangle,
frame_lvl: u8,
frame_mode: bool, /* true for 5-step mode */
frame_inh: bool,
@@ -297,6 +407,7 @@ impl<'a> APU<'a> {
fn tick_env(&mut self) {
self.pulse1.tick_env();
self.pulse2.tick_env();
+ self.triangle.tick_counter();
}
fn tick_len_swp(&mut self) {
@@ -304,11 +415,13 @@ impl<'a> APU<'a> {
self.pulse1.tick_sweep();
self.pulse2.tick_length();
self.pulse2.tick_sweep();
+ self.triangle.tick_length();
}
pub fn new(spkr: &'a mut Speaker) -> Self {
APU {
pulse1: Pulse::new(false), pulse2: Pulse::new(true),
+ triangle: Triangle::new(),
frame_lvl: 0, frame_mode: false, frame_int: false, frame_inh: false,
cpu_sampler: Sampler::new(mos6502::CPU_FREQ, CPU_SAMPLE_FREQ),
audio_sampler: Sampler::new(mos6502::CPU_FREQ, AUDIO_SAMPLE_FREQ),
@@ -320,13 +433,14 @@ impl<'a> APU<'a> {
pub fn output(&self) -> u16 {
let pulse_out = PULSE_TABLE[(self.pulse1.output() +
self.pulse2.output()) as usize];
- let tnd_out = TND_TABLE[0];
+ let tnd_out = TND_TABLE[(self.triangle.output() * 3) as usize];
pulse_out + tnd_out
}
pub fn read_status(&mut self) -> u8 {
let res = if self.pulse1.get_len() > 0 { 1 } else { 0 } |
- (if self.pulse1.get_len() > 0 { 1 } else { 0 }) << 1 |
+ (if self.pulse2.get_len() > 0 { 1 } else { 0 }) << 1 |
+ (if self.triangle.get_len() > 0 { 1 } else { 0 }) << 2 |
(if self.frame_int { 1 } else { 0 }) << 6;
if self.frame_lvl != 3 {
self.frame_int = false; /* clear interrupt flag */
@@ -343,6 +457,10 @@ impl<'a> APU<'a> {
0 => self.pulse2.disable(),
_ => self.pulse2.enable()
}
+ match data & 0x4 {
+ 0 => self.triangle.disable(),
+ _ => self.triangle.enable()
+ }
}
pub fn write_frame_counter(&mut self, data: u8) {
@@ -350,11 +468,12 @@ impl<'a> APU<'a> {
self.frame_mode = data >> 7 == 1;
}
- pub fn tick_timer(&mut self) {
+ fn tick_timer(&mut self) {
if self.cycle_even {
self.pulse1.tick_timer();
self.pulse2.tick_timer();
}
+ self.triangle.tick_timer();
}
fn tick_frame_counter(&mut self) -> bool {
diff --git a/src/bin.rs b/src/bin.rs
index 852c88b..caa3658 100644
--- a/src/bin.rs
+++ b/src/bin.rs
@@ -370,8 +370,19 @@ fn main() {
1 => Box::new(mapper::Mapper1::new(cart)),
_ => panic!("unsupported mapper {}", mapper_id)
};
+ let dur_sec = Duration::from_millis(1000);
+ let mut tim_sec = Instant::now();
+ let mut f = || {
+ let e = tim_sec.elapsed();
+ if e < dur_sec {
+ let diff = dur_sec - e;
+ sleep(diff);
+ }
+ tim_sec = Instant::now();
+ };
+
let mapper = RefCell::new(&mut (*m) as &mut mapper::Mapper);
- let mut cpu = CPU::new(CPUMemory::new(&mapper, Some(&p1ctl), None));
+ let mut cpu = CPU::new(CPUMemory::new(&mapper, Some(&p1ctl), None), &mut f);
let mut ppu = PPU::new(PPUMemory::new(&mapper), &mut win);
let mut apu = APU::new(&mut spkr);
let cpu_ptr = &mut cpu as *mut CPU;
diff --git a/src/memory.rs b/src/memory.rs
index bea84fc..e57bdf4 100644
--- a/src/memory.rs
+++ b/src/memory.rs
@@ -67,7 +67,7 @@ impl<'a> CPUMemory<'a> {
if apu.tick() {
cpu.trigger_irq()
}
- cpu.cycle -= 1;
+ cpu.tick();
}
}
@@ -86,7 +86,9 @@ impl<'a> VMem for CPUMemory<'a> {
_ => 0
}
} else if addr < 0x4020 {
+ let apu = self.bus.get_apu();
match addr {
+ 0x4015 => apu.read_status(),
0x4016 => if let Some(c) = self.ctl1 { c.read() } else { 0 },
0x4017 => if let Some(c) = self.ctl2 { c.read() } else { 0 },
_ => 0
@@ -133,6 +135,9 @@ impl<'a> VMem for CPUMemory<'a> {
0x4005 => apu.pulse2.write_reg2(data),
0x4006 => apu.pulse2.write_reg3(data),
0x4007 => apu.pulse2.write_reg4(data),
+ 0x4008 => apu.triangle.write_reg1(data),
+ 0x400a => apu.triangle.write_reg3(data),
+ 0x400b => apu.triangle.write_reg4(data),
0x4015 => apu.write_status(data),
0x4017 => apu.write_frame_counter(data),
0x4014 => ppu.write_oamdma(data, cpu),
diff --git a/src/mos6502.rs b/src/mos6502.rs
index 6c5a140..a9fac8c 100644
--- a/src/mos6502.rs
+++ b/src/mos6502.rs
@@ -602,8 +602,10 @@ pub struct CPU<'a> {
ea: u16, /* effective address */
imm_val: u8,
pub cycle: u32,
+ pub elapsed: u32,
int: Option<IntType>,
- pub mem: CPUMemory<'a>
+ pub mem: CPUMemory<'a>,
+ sec_callback: &'a mut FnMut(),
}
macro_rules! make_int {
@@ -637,7 +639,7 @@ impl<'a> CPU<'a> {
#[inline(always)] pub fn get_over(&self) -> u8 { (self.status >> 6) & 1 }
#[inline(always)] pub fn get_neg(&self) -> u8 { (self.status >> 7) & 1 }
- pub fn new(mem: CPUMemory<'a>) -> Self {
+ pub fn new(mem: CPUMemory<'a>, sec_callback: &'a mut FnMut()) -> Self {
let pc = 0;
/* nes power up state */
let a = 0;
@@ -652,7 +654,7 @@ impl<'a> CPU<'a> {
opr: 0, ea: 0, imm_val: 0,
int: None,
acc: false,
- mem}
+ mem, elapsed: 0, sec_callback}
}
pub fn start(&mut self) {
@@ -689,6 +691,15 @@ impl<'a> CPU<'a> {
//(self.cycle - cycle0) as u8
}
+ pub fn tick(&mut self) {
+ self.cycle -= 1;
+ self.elapsed += 1;
+ if self.elapsed == CPU_FREQ {
+ self.elapsed = 0;
+ (self.sec_callback)();
+ }
+ }
+
pub fn reset(&mut self) {
self.pc = read16!(self.mem, RESET_VECTOR as u16);
self.sp = self.sp.wrapping_sub(3);