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pub struct Memory {
pub mem: [u8; 65536],
pub pc: u16,
}
impl Memory {
pub fn new() -> Self {
Self {
mem: [0; 65536],
pc: 0,
}
}
pub fn load_program(&mut self, bytecode: &[u8]) {
self.mem[..bytecode.len()].copy_from_slice(bytecode)
}
pub fn read_u8(&self, addr: u16) -> u8 {
self.mem[addr as usize]
}
pub fn write_u8(&mut self, val: u8, addr: u16) {
self.mem[addr as usize] = val;
}
pub fn read_u8_next(&mut self) -> u8 {
let byte = self.mem[self.pc as usize];
self.pc = self.pc.wrapping_add(1);
byte
}
pub fn read_u16(&self, addr: u16) -> u16 {
let byte_high = self.read_u8(addr);
let byte_low = self.read_u8(addr.wrapping_add(1));
u16::from_be_bytes([byte_high, byte_low])
}
pub fn write_u16(&mut self, val: u16, addr: u16) {
let [byte_high, byte_low] = val.to_be_bytes();
self.write_u8(byte_high, addr);
self.write_u8(byte_low, addr.wrapping_add(1));
}
pub fn read_u16_next(&mut self) -> u16 {
let byte_high = self.read_u8_next();
let byte_low = self.read_u8_next();
u16::from_be_bytes([byte_high, byte_low])
}
pub fn read_pc(&self) -> u16 {
self.pc
}
pub fn write_pc(&mut self, val: u16) {
self.pc = val;
}
pub fn reset(&mut self) {
self.mem.fill(0);
self.pc = 0;
}
}
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