/// <summary>
/// Decode the instruction
/// </summary>
/// <param name="cmd"></param>
/// <returns></returns>
public static Instruction DecodeInstruction(Memory command)
{
Instruction i = new Instruction();
uint type = 0;
// get type
type = (uint)((command.ReadByte(3) & 0x0c) >> 2);
//Console.WriteLine(Convert.ToString(command.ReadWord(0),2));
switch (type)
{
case 0:
// Data Processing (00X)
if ((0x012FFF10 & command.ReadWord(0)) == 0x012FFF10)
{
i = new Branch();
}
else
{
i = new DataProcessing();
}
break;
case 1:
// Load / Store (01X)
if (command.TestFlag(0, 24) || !command.TestFlag(0, 21))
{
i = new LoadStore();
}
break;
case 2:
// Load / Store Multiple (100)
if (!command.TestFlag(0, 25))
{
//load store multiple
i = new LoadStoreMultiple();
}
// Branch Instruction (101)
else
{
if (command.TestFlag(0, 27) && !command.TestFlag(0, 26) && command.TestFlag(0, 25))
{
Logger.Instance.lastInstructionWasBranch = true;
i = new Branch();
}
}
break;
case 3:
//11
//Coprocessor
if (command.TestFlag(0, 26) && command.TestFlag(0, 25))
{
//interupt
}
break;
default:
break;
}
i.ParseCommand(command);
// get condition
i.Cond = (uint)command.ReadByte(3) >> 4;
// get type
i.Type = (uint)((command.ReadByte(3) & 0x0c) >> 2);
//
i.initialBytes = (uint)command.ReadWord(0);
// source
i.Rn = (uint)((command.ReadWord(0) & 0x000F0000) >> 16);
// destination
i.Rd = (uint)((command.ReadWord(0) & 0x0000F000) >> 12);
return i;
}
/// <summary>
/// Decode the instruction
/// </summary>
/// <param name="cmd"></param>
/// <returns></returns>
public static Instruction DecodeInstruction(Memory command)
{
Instruction i = new Instruction();
uint type = 0;
// get type
type = (uint)((command.ReadByte(3) & 0x0c) >> 2);
//Console.WriteLine(Convert.ToString(command.ReadWord(0),2));
switch (type)
{
case 0:
// Data Processing (00X)
if ((0x012FFF10 & command.ReadWord(0)) == 0x012FFF10)
{
i = new Branch();
}
else
{
i = new DataProcessing();
}
break;
case 1:
// Load / Store (01X)
if (command.TestFlag(0, 24) || !command.TestFlag(0, 21))
{
i = new LoadStore();
}
break;
case 2:
// Load / Store Multiple (100)
if (!command.TestFlag(0, 25))
{
//load store multiple
i = new LoadStoreMultiple();
}
// Branch Instruction (101)
else
{
if (command.TestFlag(0, 27) && !command.TestFlag(0, 26) && command.TestFlag(0, 25))
{
Logger.Instance.lastInstructionWasBranch = true;
i = new Branch();
}
}
break;
case 3:
//11
//Coprocessor
if (command.TestFlag(0, 26) && command.TestFlag(0, 25))
{
//interupt
}
break;
default:
break;
}
i.ParseCommand(command);
// get condition
i.Cond = (uint)command.ReadByte(3) >> 4;
// get type
i.Type = (uint)((command.ReadByte(3) & 0x0c) >> 2);
//
i.initialBytes = (uint)command.ReadWord(0);
// source
i.Rn = (uint)((command.ReadWord(0) & 0x000F0000) >> 16);
// destination
i.Rd = (uint)((command.ReadWord(0) & 0x0000F000) >> 12);
return(i);
}
