dioscuri.module.cpu
Class Instruction_CMPS_XvYv

java.lang.Object
  dioscuri.module.cpu.Instruction_CMPS_XvYv

All Implemented Interfaces:

Instruction

public class Instruction_CMPS_XvYv
extends java.lang.Object
implements Instruction

Intel opcode A7
Compare string word at address DS:(E)SI with address ES:(E)DI.
After compare, contents of SI and DI are incremented or decremented based on DF flag:
Byte: +/- 1, word: +/- 2, doubleword: +/-4.
Flags modified: CF, OF, SF, ZF, AF, and PF

Constructor Summary

Instruction_CMPS_XvYv()
Class constructor

Instruction_CMPS_XvYv(CPU processor)
Class constructor specifying processor reference

Method Summary

void	execute() Compare word at address DS:(E)SI with address ES:(E)DI; set flags accordingly. Increment/decrement both registers depending on DF flag. Flags modified: CF, OF, SF, ZF, AF, and PF

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Instruction_CMPS_XvYv

public Instruction_CMPS_XvYv()

Class constructor

Instruction_CMPS_XvYv

public Instruction_CMPS_XvYv(CPU processor)

Class constructor specifying processor reference

Parameters:

processor - Reference to CPU class

Method Detail

execute

public void execute()

Compare word at address DS:(E)SI with address ES:(E)DI; set flags accordingly.
Increment/decrement both registers depending on DF flag.
Flags modified: CF, OF, SF, ZF, AF, and PF

Specified by:

execute in interface Instruction