Mano pdp8 ComputerMano.cc
ComputerMano.cc
// Computer Mano class
// memory, registers and commands.
#ifndef COMPUTERMANO_CC
#define COMPUTERMANO_CC
#ifndef INSTRUCTIONWORD_CC
#include "InstructionWord.cc"
#endif
#ifndef STACK_CC
#include "stack.cc"
#endif
#ifndef RAM_CC
#include "RAM.cc"
#endif
#ifndef COUNTER_CC
#include "counter.cc"
#endif
#ifndef QUEUE_CC
#include "queue.cc"
#endif
class ComputerMano;
ostream& operator << (ostream& OS, ComputerMano &A);
class ComputerMano {
// Main Memory
RAM MainMemory;
// Nine registers:
InstructionWord InstructionWord_AC; // Accumulator
InstructionWord InstructionWord_AR; // Address Register
InstructionWord InstructionWord_DR; // Data Register
InstructionWord InstructionWord_IR; // Instruction Register
char OUTR; // Output Register
char INPR; // Input Register
unsigned int PC; // Program Counter
InstructionWord InstructionWord_TR; // Temporary Register
counter T_sequence_counter; // Using T_sequence_counter as a 0-15 counter,
// dropped SC and the 4x16 decoder.
// Seven flip-flops:
short int I_flip_flop;
short int S_flip_flop;
short int E_flip_flop;
short int R_flip_flop;
short int IEN_flip_flop;
short int FGI_flip_flop;
short int FGO_flip_flop;
// Control states
short int D_flip_flop;
// Indirection Control
short int si_mIndirect;
friend ostream& operator << (ostream& OS, ComputerMano &A)
{
if( DEBUG )
cout << "Computer Mano: << 0 " << endl;
OS << " Computer Mano Computer " << endl;
OS << " Nine Registers" << endl;
OS << " AC / Accumulator " << A.InstructionWord_AC << endl;
OS << " AR / Address Register " << A.InstructionWord_AR << endl;
OS << " DR / Data Register " << A.InstructionWord_DR << endl;
OS << " INPR / Input Register" << A.INPR << endl;
OS << " IR / Instruction Register" << A.InstructionWord_IR << endl;
OS << " OUTR / Output Register" << A.OUTR << endl;
OS << " PC / Program Counter" << A.PC << endl;
OS << " SC / Sequence Counter" << A.T_sequence_counter << endl;
OS << " TR / Temporary Register" << A.InstructionWord_TR << endl;
OS << endl;
OS << " Seven Flip-Flops" << endl;
OS << " E " << A.E_flip_flop << endl;
OS << " FGI " << A.FGI_flip_flop << endl;
OS << " FGO " << A.FGO_flip_flop << endl;
OS << " I " << A.I_flip_flop << endl;
OS << " IEN " << A.IEN_flip_flop << endl;
OS << " R " << A.R_flip_flop << endl;
OS << " S " << A.S_flip_flop << endl;
OS << endl;
OS << " Control States" << endl;
OS << " D " << A.D_flip_flop << endl;
OS << endl;
OS << " Main Memory" << endl;
OS << A.MainMemory << endl;
if( DEBUG )
cout << "Computer Mano: << 1 " << endl;
return OS;
}
void Decode()
{
if( DEBUG )
cout << "Computer Mano: Decode 0 " << endl;
D_flip_flop = InstructionWord_IR.getopcode();
} // end decode
int Execute()
{
if( DEBUG ) cout << "Computer Mano: Execute 0 " << endl;
T_sequence_counter++;
if ( D_flip_flop == 7 )
return ExecuteRegIo();
else
ExecuteMemRef();
return 1;
}
int ExecuteRegIo()
{
if( DEBUG )
cout << "Computer Mano: ExecuteRegIo 0 " << endl;
if ( I_flip_flop && (T_sequence_counter.getcount() == 3))
{
// execute I/O instruction
switch ( InstructionWord_IR.getRcode() ) {
case 1: IEN_flip_flop = 0; // IOF
break;
case 2: IEN_flip_flop =1; // ION
break;
case 4: if( FGO_flip_flop ) // SKO
PC++;
break;
case 8: if( FGI_flip_flop ) // SKI
PC++;
break;
case 16: OUTR = InstructionWord_AC.CellToDec(7); // OUT
FGO_flip_flop = 0;
break;
case 32: InstructionWord_AC.DecToCell( (short) INPR ); // INP
FGI_flip_flop = 0;
break;
default:
;
}
}
if( (I_flip_flop == 0) && (T_sequence_counter.getcount() == 3))
{
// execute register-reference instruction
switch( InstructionWord_AR.getopcode() ) {
case 0: S_flip_flop = 0; // HLT
T_sequence_counter.clear();
return 0;
break;
case 1: if (E_flip_flop == 0) // SZE
PC++;
break;
case 2: if( InstructionWord_AC.CellToDec() == 0) // SZA
PC++;
break;
case 3: if( InstructionWord_AC.getIcode() ) // SNA
PC++;
break;
case 4: if( InstructionWord_AC.getIcode() == 0 ) // SPA
PC++;
break;
case 5: InstructionWord_AC.increment(); // INC
break;
case 6: InstructionWord_AC.circulateleft( E_flip_flop ); // CIL
break;
case 7: InstructionWord_AC.circulateright( E_flip_flop ); // CIR
break;
case 8: ~E_flip_flop; // CME
break;
case 9: InstructionWord_AC.COMPLEMENT(); // CMA
break;
case 10: E_flip_flop = 0; // CLE
break;
case 11: InstructionWord_AC.clear(); // CLA
break;
default:
;
}
}
T_sequence_counter.clear();
return 1;
}
void ExecuteMemRef()
{
if( DEBUG )
cout << "Computer Mano: ExecuteMemRef 0 " << endl;
if ( I_flip_flop && (T_sequence_counter.getcount() == 3))
{
InstructionWord_AR = MainMemory.returncurrent(); // execute I/O
}
if ((I_flip_flop == 0) && (T_sequence_counter.getcount() == 3))
{
// execute memory-reference
switch ( D_flip_flop ) {
case 0: {
InstructionWord mem_Temp = MainMemory.returncurrent( ); // AND
InstructionWord_AC.AND( mem_Temp );
}
break;
case 1: LoadDR(); // ADD
InstructionWord_AC.ADD( InstructionWord_DR , E_flip_flop );
T_sequence_counter.clear();
break;
case 2: LoadDR(); // LDA
InstructionWord_AC = InstructionWord_DR;
T_sequence_counter.clear();
break;
case 3: {
InstructionWord mem_Temp; // STA
mem_Temp.setlocation( InstructionWord_AR.returndata() );
mem_Temp.setdata( InstructionWord_AC.returndata() );
MainMemory.LoadCell( mem_Temp );
T_sequence_counter.clear();
}
break;
case 4: PC = InstructionWord_AR.returndata(); // BUN
T_sequence_counter.clear();
break;
case 5: // BSA
break;
case 6: // ISZ
T_sequence_counter.clear();
break;
case 7:
break;
default:
;
}
}
T_sequence_counter.clear();
}
void Fetch()
{
if( DEBUG ) cout << "Computer Mano: Fetch 0 " << endl;
if( LoadAR() && (T_sequence_counter.getcount() == 1) )
{
if( DEBUG ) cout << "Computer Mano: Fetch 1 " << endl;
MainMemory.locate( InstructionWord_AR );
InstructionWord_IR = MainMemory.returncurrent();
if( DEBUG ) cout << "Computer Mano: Fetch 2, InstructionWord_IR is " << InstructionWord_IR << endl;
PC++;
T_sequence_counter++;
}
}
short LoadAR()
{
if( DEBUG ) cout << "Computer Mano: LoadAR 0 " << endl;
if( T_sequence_counter.getcount() )
return 0;
InstructionWord_AR = PC;
T_sequence_counter++;
return 1;
}
void LoadDR()
{
if( DEBUG )
cout << "Computer Mano: LoadDR 0 " << endl;
T_sequence_counter++;
InstructionWord_DR = MainMemory.returncell( InstructionWord_AR );
}
public:
ComputerMano()
{
OUTR = '\0';
INPR = '\0';
D_flip_flop = 0;
I_flip_flop = 0;
S_flip_flop = 0;
E_flip_flop = 0;
R_flip_flop = 0;
IEN_flip_flop = 0;
FGI_flip_flop = 0;
FGO_flip_flop = 0;
PC = 0;
si_mIndirect = 0;
}
ComputerMano(const ComputerMano &V)
{
InstructionWord_AC = V.InstructionWord_AC;
InstructionWord_AR = V.InstructionWord_AR;
InstructionWord_DR = V.InstructionWord_DR;
InstructionWord_IR = V.InstructionWord_IR;
OUTR = V.OUTR;
INPR = V.INPR;
InstructionWord_TR = V.InstructionWord_TR;
PC = V.PC;
D_flip_flop = V.D_flip_flop;
I_flip_flop = V.I_flip_flop;
S_flip_flop = V.S_flip_flop;
E_flip_flop = V.E_flip_flop;
R_flip_flop = V.R_flip_flop;
IEN_flip_flop = V.IEN_flip_flop;
FGI_flip_flop = V.FGI_flip_flop;
FGO_flip_flop = V.FGO_flip_flop;
si_mIndirect = V.si_mIndirect;
MainMemory = V.MainMemory;
}
~ComputerMano(){}
// Load the assembly code
void load( queue<InstructionWord> mem_NewCell )
{
if( DEBUG ) cout << "Computer Mano: load 0 " << endl;
int i_test = 0;
while( !mem_NewCell.isempty() )
{
i_test++;
InstructionWord IW;
mem_NewCell.dequeue( IW );
MainMemory.LoadCell( IW );
} // while
if( DEBUG ) cout << "Computer Mano: load 1. " << i_test << " cells loaded " << endl;
} // void load( queue<InstructionWord> mem_NewCell )
void reset()
{
if( DEBUG ) cout << "Computer Mano: Reset 0 " << endl;
D_flip_flop = 0;
I_flip_flop = 0;
S_flip_flop = 0;
E_flip_flop = 0;
R_flip_flop = 0;
IEN_flip_flop = 0;
FGI_flip_flop = 0;
FGO_flip_flop = 0;
T_sequence_counter.clear();
OUTR = '\0';
INPR = '\0';
MainMemory.erase();
}
void run()
{
if( DEBUG ) cout << "Computer Mano: Run 0 " << endl;
// Make sure there is something in memory
if( MainMemory.census() )
{
if( DEBUG ) cout << "Computer Mano: Run 1 " << endl;
do {
cout << "Computer Mano: Run 1 " << endl;
T_sequence_counter.clear();
Fetch(); // Fetch instruction
Decode(); // Decode instruction
InstructionWord_AR = InstructionWord_IR.CellToDec(); // load raw address
I_flip_flop = InstructionWord_IR.getIcode(); // get indirect flag
}
while( Execute() ); // Execute Instruction
} // if
} // run
};
#endif // ComputerMano_CC
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Parent Article: Mano PDP-8 Simulation Project Source Code
