opcodemovx.java

来自「這是一個8051的模擬器 以java寫成」· Java 代码 · 共 32 行

/**
 * Projet de langage JAVA IFITEP 3 2005 - Simulateur 8051 
 * <p> 
 * D閒inition de l'instruction MOVX.
 * Cf.:
 *  - documentation technique 8051
 *  - Ouvrage "Microcontroleur 8051 et 8052", edition Dunod
 *  
 * @author Matthieu SIMON
 * @version 1.0 du 14/06/05
 */
public class OpcodeMOVX extends Opcode {
	public void execute(CORE_CPU8051 cpu) throws OpcodeException {
		int dest, src;
		if((dest = decodeAddressingMode(cpu.getCurrentLine().getOperand(1))) == Integer.MAX_VALUE)
			throw new OpcodeException(this, "Bad Addressing Mode");
		if((src = decodeAddressingMode(cpu.getCurrentLine().getOperand(2))) == Integer.MAX_VALUE)
			throw new OpcodeException(this, "Bad Addressing Mode");
		
		if(src >= CORE_CPU8051.externalDataMem.length || dest >= CORE_CPU8051.externalDataMem.length)
			throw new OpcodeException(this, "Adressing is away from External Memory which is about " + 
					(CORE_CPU8051.externalDataMem.length/1024) + "kbytes");
		
		if(cpu.getCurrentLine().getOperand(1).equals("a")) // lecture externe
			CORE_CPU8051.internalDataMem[CORE_CPU8051.ACC] = CORE_CPU8051.externalDataMem[src];
		else if(cpu.getCurrentLine().getOperand(2).equals("a")) // ecriture externe
			CORE_CPU8051.externalDataMem[dest] = CORE_CPU8051.internalDataMem[CORE_CPU8051.ACC];
		else
			throw new OpcodeException(this, "Bad Register Addressing");
		cpu.incCyclesCount(2);
	}
}