diff options
| -rw-r--r-- | src/core.rs | 38 |
1 files changed, 32 insertions, 6 deletions
diff --git a/src/core.rs b/src/core.rs index a3b4541..37886c5 100644 --- a/src/core.rs +++ b/src/core.rs @@ -6,6 +6,7 @@ pub enum Opname { Nop, Ajmp, Ljmp, + Jnz, Mov, Push, Pop, @@ -87,6 +88,7 @@ const OPCODE_LJMP: u8 = 0x02; const OPCODE_AJMP_P1: u8 = 0x21; const OPCODE_AJMP_P2: u8 = 0x41; const OPCODE_AJMP_P3: u8 = 0x61; +const OPCODE_JNZ: u8 = 0x70; const OPCODE_MOV_A_DATA: u8 = 0x74; const OPCODE_MOV_DIRECT_DATA: u8 = 0x75; const OPCODE_SJMP: u8 = 0x80; @@ -151,6 +153,12 @@ const OP_LUT: [IncompleteOp; u8::max_value() as usize + 1] = { operand1: Some(IncompleteOperand::Addr11(3)), operand2: None, }; + lut[OPCODE_JNZ as usize] = IncompleteOp { + opname: Opname::Jnz, + size: 2, + operand1: Some(IncompleteOperand::Reladdr), + operand2: None, + }; lut[OPCODE_MOV_A_DATA as usize] = IncompleteOp { opname: Opname::Mov, size: 2, @@ -275,7 +283,7 @@ const OP_LUT: [IncompleteOp; u8::max_value() as usize + 1] = { }; impl Register { - fn to_ram_offset(&self) -> u8 { + fn to_ram_offset(self) -> u8 { match self { Register::R0 => RAM_OFFSET_R0, Register::R1 => RAM_OFFSET_R1, @@ -403,6 +411,16 @@ impl Core { panic!("LJMP has no operand given") } } + Opname::Jnz => { + if let Some(operand) = op.operand1 { + match operand { + Operand::Reladdr(addr) => self.jnz(addr), + _ => panic!("JNZ got incompatible operand"), + } + } else { + panic!("JNZ has no operand given") + } + } } } @@ -420,7 +438,7 @@ impl Core { Operand::Reladdr(self.rom.array[(self.pc as usize + offset)] as i8) } IncompleteOperand::Addr11(high) => Operand::Addr11( - self.rom.array[(self.pc as usize + offset)] as u16 + (u16::from(high) << 8), + u16::from(self.rom.array[(self.pc as usize + offset)]) + (u16::from(high) << 8), ), IncompleteOperand::Addr16 => Operand::Addr16( (u16::from(self.rom.array[(self.pc as usize + offset)]) << 8) @@ -452,12 +470,20 @@ impl Core { self.pc = (self.pc as i16 + i16::from(reladdr)) as u16; } - fn ajmp(&mut self, pageaddr: u16) { - self.pc = (self.pc & !0x4FFu16) + pageaddr; + fn ajmp(&mut self, addr11: u16) { + assert!(addr11 <= 0x4FFu16); + // Clear 11 low bits of PC and add address, that is within these 11 bits + self.pc = (self.pc & !0x4FFu16) & addr11; } - fn ljmp(&mut self, pageaddr: u16) { - self.pc = pageaddr; + fn ljmp(&mut self, addr: u16) { + self.pc = addr; + } + + fn jnz(&mut self, reladdr: i8) { + if self.ram[usize::from(RAM_OFFSET_ACC)] != 0 { + self.pc = (self.pc as i16 + i16::from(reladdr)) as u16; + } } } |