Refactor timer

src/bus.rs

@@ -13,7 +13,7 @@ use crate::ppu::{
     DMA_ADDRESS,
 };
 use crate::cpu::{Interrupt};
-use crate::timer::{TIMER_DIVIDER_REGISTER_ADDRESS};
+use crate::timer::{Timer, TIMER_DIVIDER_REGISTER_ADDRESS};
 use crate::joypad::{Joypad, JOYPAD_ADDRESS};
 
 pub struct AddressRange {
@@ -53,12 +53,12 @@ pub const INTERRUPT_FLAG_ADDRESS: u16 = 0xFF0F;
 pub struct Bus {
     game_rom: ROM,
     data: [u8; 0x10000],
-    pub reset_timer: bool,
     joypad: Rc<RefCell<Joypad>>,
+    timer: Rc<RefCell<Timer>>,
 }
 
 impl Bus {
-    pub fn new(joypad: Rc<RefCell<Joypad>>) -> Self {
+    pub fn new(joypad: Rc<RefCell<Joypad>>, timer: Rc<RefCell<Timer>>) -> Self {
         let args: Vec<String> = std::env::args().collect();
         if args.len() < 2 {
             println!("Please, specify a ROM file");
@@ -98,8 +98,8 @@ impl Bus {
         Self {
             data,
             game_rom,
-            reset_timer: false,
             joypad,
+            timer,
         }
     }
 
@@ -110,6 +110,8 @@ impl Bus {
             return 0b11100000 | self.data[address as usize];
         } else if address == JOYPAD_ADDRESS {
             return self.joypad.borrow().read(self.data[address as usize]);
+        }  else if address == TIMER_DIVIDER_REGISTER_ADDRESS {
+            return self.timer.borrow().read_divider();
         }
         self.data[address as usize]
     }
@@ -137,7 +139,7 @@ impl Bus {
             self.data[address as usize] = data;
             self.data[(WORK_RAM_1.begin() + (address - ECHO_RAM.begin())) as usize] = data; // Copy to the working RAM
         } else if address == TIMER_DIVIDER_REGISTER_ADDRESS {
-            self.reset_timer = true;
+            self.timer.borrow_mut().reset();
         } else if address == LCD_CONTROL_ADDRESS {
             self.data[address as usize] = data;
             // Check if LCD is being turned on or off

src/emulator.rs

@@ -14,19 +14,20 @@ pub struct Emulator {
     cpu: CPU,
     ppu: PPU,
     bus: Bus,
-    timer: Timer,
+    timer: Rc<RefCell<Timer>>,
     joypad: Rc<RefCell<Joypad>>,
 }
 
 impl Emulator {
     pub fn new() -> Self {
         let joypad = Rc::new(RefCell::new(Joypad::new()));
+        let timer = Rc::new(RefCell::new(Timer::new()));
         Self {
             cpu: CPU::new(),
             ppu: PPU::new(),
-            bus: Bus::new(Rc::clone(&joypad)),
+            bus: Bus::new(Rc::clone(&joypad), Rc::clone(&timer)),
-            timer: Timer::new(),
+            timer,
-            joypad: joypad,
+            joypad,
         }
     }
 
@@ -107,12 +108,8 @@ impl Emulator {
         self.cpu.reset_cycles();
         while self.cpu.get_cycles().to_t().0 <= cpu_cycles.0 {
             self.cpu.run(&mut self.bus);
-            if self.bus.reset_timer {
-                self.bus.reset_timer = false;
-                self.timer.reset(&mut self.bus);
-            }
             self.ppu.do_cycles(&mut self.bus, self.cpu.get_last_op_cycles().to_t(), frame_buffer);
-            self.timer.do_cycles(&mut self.bus, self.cpu.get_last_op_cycles().to_t());
+            self.timer.borrow_mut().do_cycles(&mut self.bus, self.cpu.get_last_op_cycles().to_t());
 
             // 1 CPU cycle = 238.42ns
             // thread::sleep(time::Duration::from_nanos((self.cpu.get_last_op_cycles().0 * 238).try_into().unwrap()));
@@ -125,12 +122,8 @@ impl Emulator {
         let mut frame: [u8; 144 * 160 * 4] = [0; 144 * 160 * 4];
         while !exit {
             self.cpu.run(&mut self.bus);
-            if self.bus.reset_timer {
-                self.bus.reset_timer = false;
-                self.timer.reset(&mut self.bus);
-            }
             self.ppu.do_cycles(&mut self.bus, self.cpu.get_last_op_cycles().to_t(), &mut frame);
-            self.timer.do_cycles(&mut self.bus, self.cpu.get_last_op_cycles().to_t());
+            self.timer.borrow_mut().do_cycles(&mut self.bus, self.cpu.get_last_op_cycles().to_t());
 
             // exit = self.cpu.get_exec_calls_count() >= 1258895; // log 1
             exit = self.cpu.get_exec_calls_count() >= 161502; // log 2

src/timer.rs

@@ -28,9 +28,13 @@ impl Timer {
         }
     }
 
-    pub fn reset(&mut self, bus: &mut Bus) {
+    pub fn read_divider(&self) -> u8 {
+        self.divider.to_be_bytes()[0]
+    }
+
+    pub fn reset(&mut self) {
+        println!("Reset divider");
         self.divider = 0;
-        bus.force_write(TIMER_DIVIDER_REGISTER_ADDRESS, 0);
     }
     
     pub fn do_cycles(&mut self, bus: &mut Bus, cycles: Cycles) {
@@ -41,7 +45,6 @@ impl Timer {
             self.cycle(bus);
             count += 1;
         }
-        bus.force_write(TIMER_DIVIDER_REGISTER_ADDRESS, self.divider.to_be_bytes()[0]);
     }
 
     fn cycle(&mut self, bus: &mut Bus) {