diff options
Diffstat (limited to 'src/memory.rs')
-rw-r--r-- | src/memory.rs | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/src/memory.rs b/src/memory.rs new file mode 100644 index 0000000..755c4bc --- /dev/null +++ b/src/memory.rs @@ -0,0 +1,62 @@ +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; + } +} |