45 lines
1.4 KiB
Java
45 lines
1.4 KiB
Java
package processor.pipeline;
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import processor.Processor;
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public class InstructionFetch {
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Processor containingProcessor;
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IF_EnableLatchType IF_EnableLatch;
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IF_OF_LatchType IF_OF_Latch;
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EX_IF_LatchType EX_IF_Latch;
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public InstructionFetch(Processor containingProcessor, IF_EnableLatchType iF_EnableLatch, IF_OF_LatchType iF_OF_Latch, EX_IF_LatchType eX_IF_Latch)
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{
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this.containingProcessor = containingProcessor;
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this.IF_EnableLatch = iF_EnableLatch;
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this.IF_OF_Latch = iF_OF_Latch;
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this.EX_IF_Latch = eX_IF_Latch;
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}
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public void performIF()
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{ if(!IF_EnableLatch.isFreeze()){
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if(EX_IF_Latch.isIF_enable()){
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containingProcessor.getRegisterFile().setProgramCounter(EX_IF_Latch.getPC()-1);
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EX_IF_Latch.setIF_enable(false);
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IF_OF_Latch.setOF_enable(false);
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System.out.println("IF: PC set to " + EX_IF_Latch.getPC());
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} // if EX_IF_Latch is enabled, set PC to EX_IF_Latch's PC and wait for next cycle (1 nop)
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else if(IF_EnableLatch.isIF_enable() || EX_IF_Latch.isIF_enable())
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{
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int currentPC = containingProcessor.getRegisterFile().getProgramCounter();
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int newInstruction = containingProcessor.getMainMemory().getWord(currentPC);
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IF_OF_Latch.setInstruction(newInstruction);
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containingProcessor.getRegisterFile().setProgramCounter(currentPC + 1);
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IF_EnableLatch.setIF_enable(true);
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IF_OF_Latch.setOF_enable(true);
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}
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}else{
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IF_EnableLatch.setFreeze(false);
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}
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}
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}
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