name.martingeisse.esdk.picoblaze.simulator.instruction.PicoblazeInstructionMemory.java Source code

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Here is the source code for name.martingeisse.esdk.picoblaze.simulator.instruction.PicoblazeInstructionMemory.java

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/**
 * Copyright (c) 2011 Martin Geisse
 *
 * This file is distributed under the terms of the MIT license.
 */

package name.martingeisse.esdk.picoblaze.simulator.instruction;

import java.io.File;
import java.io.IOException;

import name.martingeisse.esdk.picoblaze.PsmBinUtil;
import name.martingeisse.esdk.picoblaze.simulator.PicoblazeSimulatorException;

import org.apache.commons.io.FileUtils;

/**
 * Default implementation of {@link IPicoblazeInstructionMemory} that
 * uses a 1024-element int array.
 */
public class PicoblazeInstructionMemory implements IPicoblazeInstructionMemory {

    /**
     * the instructions
     */
    private int[] instructions;

    /**
     * Constructor.
     */
    public PicoblazeInstructionMemory() {
    }

    /**
     * Constructor.
     * @param instructions the instructions
     */
    public PicoblazeInstructionMemory(final int[] instructions) {
        this.instructions = instructions;
    }

    /**
     * Getter method for the instructions.
     * @return the instructions
     */
    public int[] getInstructions() {
        return instructions;
    }

    /**
     * Setter method for the instructions.
     * @param instructions the instructions to set
     */
    public void setInstructions(final int[] instructions) {
        if (instructions.length != 1024) {
            throw new IllegalArgumentException("invalid instruction array length (1024 expected): " + instructions);
        }
        this.instructions = instructions;
    }

    /* (non-Javadoc)
     * @see name.martingeisse.esdk.picoblaze.simulator.instruction.IPicoblazeInstructionMemory#getInstruction(int)
     */
    @Override
    public int getInstruction(int address) throws PicoblazeSimulatorException {
        if (address < 0 || address >= 1024) {
            throw new PicoblazeSimulatorException("invalid instruction address: " + address);
        }
        if (instructions == null) {
            throw new PicoblazeSimulatorException("instructions array is null");
        }
        return instructions[address];
    }

    /**
     * Creates a {@link PicoblazeInstructionMemory} instance from a .psmbin file.
     * @param file the file to load
     * @return the memory instance
     * @throws IOException on I/O errors
     */
    public static PicoblazeInstructionMemory createFromPsmBinFile(File file) throws IOException {
        byte[] encodedInstructions = FileUtils.readFileToByteArray(file);
        int[] instructions = PsmBinUtil.decodePsmBin(encodedInstructions);
        return new PicoblazeInstructionMemory(instructions);
    }

}