//--------------------------------------------------------------
// Purpose: Loads contents of sequential memory addresses starting at
// instr.RN into registers specified in <instr>
// Returns: nothing
//--------------------------------------------------------------
public void LDMFD(LoadStoreMultiple instr, bool generateDisasm)
{
instr.disasm.instruction = "ldmfd";
uint count = 0;
uint backup = instr.regList, mask = 0x00000001;
ArrayList regList = new ArrayList(); // store addresses of registers to be stored
ArrayList disasmList = new ArrayList();
if (!generateDisasm)
{
for (int i = 0; i < 17; i++, count += 4)
{
byte lsb = (byte)(backup & mask);
if (lsb == 1)
{
regList.Add(count);
}
backup >>= 1;
}
uint RN = Computer.GetCPU().registers.ReadWord((uint)instr.RN * 4);
uint address = RN;
for (int i = 0; i < regList.Count; i++)
{
//if (!instr.U) address -= 4;
uint data = Computer.GetCPU().progRAM.ReadWord(address);
Computer.GetCPU().registers.WriteWord((uint)regList[i], data);
address += 4;
}
if (instr.W)
{
Computer.GetCPU().registers.WriteWord((uint)instr.RN * 4, RN + ((uint)regList.Count * 4));
}
}
else
{
for (int i = 0; i < 17; i++, count += 4)
{
byte lsb = (byte)(backup & mask);
if (lsb == 1)
{
disasmList.Add("r" + count / 4);
}
backup >>= 1;
}
instr.disasm.value = "r" + instr.RN.ToString() + (instr.W ? "" : "!") + ", {";
foreach (string s in disasmList)
{
instr.disasm.value += s + ", ";
}
instr.disasm.value = instr.disasm.value.Substring(0, instr.disasm.value.Length - 2) + "}";
}
// read value at instr.RN into lowest register in instr.regList
// continue reading values in sequential memory addresses into registers listed from least to greatest
// read direction is specified by instr.U
}
//--------------------------------------------------------------
// Purpose: Stores multiple registers into memory starting at address
// in instr.RN
// Returns: nothing
//--------------------------------------------------------------
public void STMFD(LoadStoreMultiple instr, bool generateDisasm)
{
instr.disasm.instruction = "stmfd";
uint count = 0;
uint backup = instr.regList, mask = 0x00000001;
ArrayList regList = new ArrayList(); // store addresses of registers to be stored
ArrayList disasmList = new ArrayList();
if (!generateDisasm)
{
for (int i = 0; i < 17; i++, count += 4)
{
byte lsb = (byte)(backup & mask);
if (lsb == 1)
{
regList.Add(count);
}
backup >>= 1;
}
uint RN = Computer.GetCPU().registers.ReadWord((uint)instr.RN * 4);
uint address = RN - ((uint)regList.Count * 4);
for (int i = 0; i < regList.Count; i++)
{
//if (!instr.U) address -= 4;
uint data = Computer.GetCPU().registers.ReadWord((uint)regList[i]);
Computer.GetCPU().progRAM.WriteWord(address, data);
address += 4;
}
if (instr.W)
{
Computer.GetCPU().registers.WriteWord((uint)instr.RN * 4, RN - ((uint)regList.Count * 4));
}
}
else
{
for (int i = 0; i < 17; i++, count += 4)
{
byte lsb = (byte)(backup & mask);
if (lsb == 1)
{
disasmList.Add("r" + count / 4);
}
backup >>= 1;
}
instr.disasm.value = "r" + instr.RN.ToString() + (instr.W ? "" : "!") + ", {";
foreach (string s in disasmList)
{
instr.disasm.value += s + ", ";
}
instr.disasm.value = instr.disasm.value.Substring(0, instr.disasm.value.Length - 2) + "}";
}
// store values in registers held in instr.regList to address in instr.RN
// if instr.W is set, write the current PC value back into the PC
}
public Instruction Create(uint data)
{
byte operationType = Instruction.GetOperationType(data);
bool bit4 = Memory.TestFlagInData(data, 4);
switch (operationType)
{
case 0x0: // 000
if (Memory.ExtractBits(data, 21, 24) == 0 && (Memory.ExtractBits(data, 4, 7) >> 4) == 0x09) // instruction is a MUL
{
Data dInstr = new Data(data);
dInstr.DataMul();
dInstr.ExecuteInstruction(true);
return(dInstr);
}
else if (bit4 == false) // Data Register, Immediate-shifted Register
{
Data dInstr = new Data(data);
dInstr.DataRegImmShiftedReg();
dInstr.ExecuteInstruction(true);
return(dInstr);
}
else if (bit4 == true && Memory.ExtractBits(data, 20, 24) >> 20 == 0x12) // BX instruction
{
Branch bInstr = new Branch(data);
bInstr.Branch();
bInstr.ExecuteInstruction(true);
return(bInstr);
}
else // Data Register-shifted Immediate
{
Data dInstr = new Data(data);
dInstr.DataRegShiftedReg();
dInstr.ExecuteInstruction(true);
return(dInstr);
}
case 0x1: // 001 - Data Immediate
Data dataInstr = new Data(data);
dataInstr.DataImmediate();
dataInstr.ExecuteInstruction(true); // generate disassembly
return(dataInstr);
case 0x2: // 010 - Load/Store Immediate
LdStore ldstrInstr = new LdStore(data);
ldstrInstr.LdStrImmediate();
ldstrInstr.ExecuteInstruction(true);
return(ldstrInstr);
case 0x3: // 011 - Load/Store Immediate-shifted Register
LdStore ldstInstr = new LdStore(data);
ldstInstr.LdStrImmShiftedReg();
ldstInstr.ExecuteInstruction(true);
return(ldstInstr);
case 0x4: // 100 - Load/Store Multiple
LoadStoreMultiple ldstrMul = new LoadStoreMultiple(data);
ldstrMul.LdStrMultiple();
ldstrMul.ExecuteInstruction(true);
return(ldstrMul);
case 0x5: // 101 - Branch
Branch b = new Branch(data);
b.Branch();
b.ExecuteInstruction(true);
return(b);
case 0x07: // 111 - SWI
SWI swiInstr = new SWI(data);
swiInstr.LoadDataSWI();
swiInstr.ExecuteInstruction(true);
return(swiInstr);
default:
// an unsupported instruction was provided
Instruction i = new Instruction();
return(i);
}
}
