public void decode(ref string instr, ref Multiplexer reg_des, ref Register_File rf, ref Control_Unit cu)
{
while (instr.Length < 32)
{
instr = instr.Insert(0, "0");
}
rf.ReadRegister1 = instr.Substring(8, 4);//it sends rs to reg file
rf.ReadRegister2 = instr.Substring(12, 4);
reg_des.Zero = instr.Substring(12, 4);
reg_des.One = instr.Substring(16, 4);
cu.Opcode = instr.Substring(4, 4);
}
public bool set_controls(ref Register_File rf, ref Multiplexer alu_src, ref Memory mem,
ref ALU alu, ref Multiplexer memtoreg, ref Branch_AND_Gate bag,
ref Multiplexer regdest, ref Multiplexer ec,
ref Multiplexer writedt_dest, ref Multiplexer jalr_or_pc,
ref Multiplexer jump_or_pc)
{
switch (Opcode)
{
case "0000":
regdest.Destination = true;
alu_src.Destination = false;
memtoreg.Destination = true;
rf.RegWrite = true;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
//ec.Destination = true; don't care
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "000";
break; // extension control = don't care
case "0001":
regdest.Destination = true;
alu_src.Destination = false;
memtoreg.Destination = true;
rf.RegWrite = true;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
//ec.Destination = false; don't care
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "001";
break;
case "0010":
regdest.Destination = true;
alu_src.Destination = false;
memtoreg.Destination = true;
rf.RegWrite = true;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
//ec.Destionation
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "010";
break;
case "0011":
regdest.Destination = true;
alu_src.Destination = false;
memtoreg.Destination = true;
rf.RegWrite = true;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
//ec.Destination
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "011";
break;
case "0100":
regdest.Destination = true;
alu_src.Destination = false;
memtoreg.Destination = true;
rf.RegWrite = true;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
//ec.Destination
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "100";
break;
case "0101":
regdest.Destination = false;
alu_src.Destination = true;
memtoreg.Destination = true;
rf.RegWrite = true;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
ec.Destination = false;
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "000";
break;
case "0110":
regdest.Destination = false;
alu_src.Destination = true;
memtoreg.Destination = true;
rf.RegWrite = true;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
ec.Destination = false;
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "010";
break;
case "0111":
regdest.Destination = false;
alu_src.Destination = true;
memtoreg.Destination = true;
rf.RegWrite = true;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
ec.Destination = true;
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "011";
break;
case "1000":
regdest.Destination = false;
alu_src.Destination = true;
memtoreg.Destination = true;
rf.RegWrite = true;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
ec.Destination = true;
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "111";
break;
case "1001":
regdest.Destination = false;
alu_src.Destination = true;
memtoreg.Destination = false;
rf.RegWrite = true;
mem.MemRead = true;
mem.MemWrite = false;
bag.Control_Unit = false;
ec.Destination = false;
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "000";
break;
case "1010":
//regdest.Destination = false; don't care
alu_src.Destination = true;
//memtoreg.Destination = false; don't care
rf.RegWrite = false;
mem.MemRead = false;
mem.MemWrite = true;
bag.Control_Unit = false;
ec.Destination = false;
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "000";
break;
case "1011":
//regdest.Destination = false; don't care
alu_src.Destination = false;
//memtoreg.Destination = false; don't care
rf.RegWrite = false;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = true;
ec.Destination = false;
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "001";
break;
case "1100":
regdest.Destination = false;
//alu_src.Destination = true;
memtoreg.Destination = false;
rf.RegWrite = true;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
ec.Destination = false;
writedt_dest.Destination = false;
jalr_or_pc.Destination = true;
jump_or_pc.Destination = false;
alu.Alu_Ctrl = "000";
break;
case "1101":
//regdest.Destination = false; don't care
alu_src.Destination = true;
memtoreg.Destination = false;
rf.RegWrite = false;
mem.MemRead = false;
mem.MemWrite = false;
bag.Control_Unit = false;
ec.Destination = false;
writedt_dest.Destination = true;
jalr_or_pc.Destination = false;
jump_or_pc.Destination = true;
alu.Alu_Ctrl = "000";
break;
case "1110":
return(true);
}
return(false);
}