public override PICInstruction Decode(ushort uInstr, PICDisassemblerBase dasm)
{
byte fsrnum = (byte)uInstr.Extract(6, 2);
if (fsrnum >= 3)
{
return(dasm.CreateInvalidInstruction());
}
var imm6 = (byte)uInstr.Extract(0, 6);
return(new PICInstructionFSRUArith(mnemonic, fsrnum, imm6));
}
public override PICInstruction Decode(ushort uInstr, PICDisassemblerBase dasm)
{
if (PICMemoryDescriptor.ExecMode != PICExecMode.Extended)
{
return(new PICInstructionNoOpnd(Mnemonic.invalid));
}
byte fsrnum = (byte)uInstr.Extract(6, 2);
if (fsrnum >= 3)
{
return(dasm.CreateInvalidInstruction());
}
var imm6 = (byte)uInstr.Extract(0, 6);
return(new PICInstructionFSRUArith(mnemonic, fsrnum, imm6));
}
public override PICInstruction Decode(ushort uInstr, PICDisassemblerBase dasm)
{
// This is a 3-word instruction.
if (!GetAddlInstrWord(dasm.rdr, out ushort word2) || !GetAddlInstrWord(dasm.rdr, out ushort word3))
{
return(new PICInstructionNoOpnd(Mnemonic.invalid));
}
ushort srcaddr = (ushort)((uInstr.Extract(0, 4) << 10) | word2.Extract(2, 10));
ushort dstaddr = (ushort)(word3.Extract(0, 12) | (word2.Extract(0, 2) << 12));
// PCL, TOSL, TOSH, TOSU are invalid destinations.
if (PICRegisters.NotAllowedDest(dstaddr))
{
return(dasm.CreateInvalidInstruction());
}
return(new PICInstructionMem2Mem(mnemonic, srcaddr, dstaddr));
}
public override PICInstruction Decode(ushort uInstr, PICDisassemblerBase dasm)
{
byte fsrnum = (byte)uInstr.Extract(4, 4);
if (fsrnum >= 3)
{
return(dasm.CreateInvalidInstruction());
}
// This is a 2-word instruction.
if (!GetAddlInstrWord(dasm.rdr, out ushort word2))
{
return(new PICInstructionNoOpnd(Mnemonic.invalid));
}
if (word2 > 0x3FF) // Second word must be 'xxxx-00kk-kkkk-kkkk'
{
return(new PICInstructionNoOpnd(Mnemonic.invalid));
}
var imm14 = ((ushort)((uInstr.Extract(0, 4) << 10) | word2));
return(new PICInstructionLFSRLoad(mnemonic, fsrnum, imm14));
}
