text: /**********************************/
  /*                                */
  /*  Copyright 2000, David Grant   */
  /*                                */
  /*  see LICENSE for more details  */
  /*                                */
  /**********************************/
  
  #include "coldfire.h"
  
  /* Subtract instruction */
  
  /* Format 
     
   15  14  13  12  11  10   9   8   7   6   5   4   3   2   1   0
  +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  | 1 | 0 | 0 | 1 | Register  |  OPmode   |  EA Mode  |EA Register|
  +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  
  */
  
  int SUBTime[2][8]={{1, 3, 3, 3, 3, 4, 3, 1  },
  	          {-1, 3, 3, 3, 3, 4, 3, -1 }};
  
  
  INSTRUCTION_5ARGS(SUB,
  	unsigned Code1,4,
  	unsigned Register,3,
  	unsigned OPMode,3,
  	unsigned EAMode,3,
  	unsigned EARegister,3);
  
  static void execute(void)
  {
  	struct _Address Source,Destination;
  	unsigned int Result, SValue, DValue;
  	SUB_Instr Instr;
  	Memory_RetrWordFromPC(&Instr.Code);
  
  /*	printf("SUB: Register=%d, OPMode=%d, EAMode=%d, EARegister=%d\n", Register, OPMode, EAMode,EARegister);*/
  	if(Instr.Bits.OPMode==2) { /* <EA>y + Dx */
  		if(!EA_GetFromPC(&Source, 32, Instr.Bits.EAMode, Instr.Bits.EARegister)) return;
  		if(!EA_GetFromPC(&Destination, 32, 0, Instr.Bits.Register)) return;
  	} else if(Instr.Bits.OPMode==6) { /* Dy + <EA>x -> <EA>x */
  		if(Instr.Bits.EAMode==0) {
  			SKYEYE_ERR("May not specify Dx for destination when source is Dx");
  			return;
  		} else if(Instr.Bits.EAMode==1) {
  			SKYEYE_ERR("May not specify Ax for destination when source is Dx");
  			return;
  		}
  		if(!EA_GetFromPC(&Source, 32, 0, Instr.Bits.Register)) return;
  		if(!EA_GetFromPC(&Destination, 32, Instr.Bits.EAMode, Instr.Bits.EARegister)) return;
  	} else {
  		SKYEYE_ERR("Unknown opcode %x\n", Instr.Bits.OPMode);
  		return;
  	}
  	EA_GetValue(&SValue, &Source);
  	EA_GetValue(&DValue, &Destination);
  
  	Result = DValue - SValue;
  
  
  	/* Set the status register */
  	SR_Set(I_SUB, SValue, DValue, Result);
  
  	EA_PutValue(&Destination, Result);
  
  
  	if(Instr.Bits.OPMode==2)  /* <EA>y + Dx */
  		cycle(SUBTime[0][cycle_EA(Instr.Bits.EARegister,Instr.Bits.EAMode)]);
  	else cycle(SUBTime[1][cycle_EA(Instr.Bits.EARegister,Instr.Bits.EAMode)]);
  
  	return;
  }
  
  static int disassemble(char *Instruction, char *Arg1, char *Arg2)
  {
  	SUB_Instr Instr;
  	Memory_RetrWordFromPC(&Instr.Code);
  	sprintf(Instruction, "SUB.L");
  	if(Instr.Bits.OPMode==2) { /* <EA>y & Dx */
  		Addressing_Print(32, Instr.Bits.EAMode, Instr.Bits.EARegister, Arg1);
  		Addressing_Print(32, 0, Instr.Bits.Register, Arg2);
  	} else {
  		Addressing_Print(32, 0, Instr.Bits.Register, Arg1);
  		Addressing_Print(32, Instr.Bits.EAMode, Instr.Bits.EARegister, Arg2);
  	}
   	return 0;
  }
  
  int sub_5206_register(void)
  {
  	instruction_register(0x9000, 0xF000, &execute, &disassemble);
  	return 1;
  }
  