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40 lines
917 B
C++
40 lines
917 B
C++
//
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// Decoder.hpp
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// Clock Signal
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//
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// Created by Thomas Harte on 10/04/2022.
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// Copyright © 2022 Thomas Harte. All rights reserved.
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//
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#ifndef Decoder_hpp
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#define Decoder_hpp
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#include "Instruction.hpp"
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namespace InstructionSet {
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namespace M68k {
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/*!
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A stateless decoder that can map from instruction words to preinstructions
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(i.e. enough to know the operation and size, and either know the addressing mode
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and registers or else know how many further extension words are needed).
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*/
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class Predecoder {
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public:
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Preinstruction decode(uint16_t instruction);
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private:
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// Page by page decoders; each gets a bit ad hoc so
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// it is neater to separate them.
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Preinstruction decode8(uint16_t instruction);
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Preinstruction decodeC(uint16_t instruction);
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// Specific instruction decoders.
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template <Operation operation> Preinstruction decode(uint16_t instruction);
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};
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}
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}
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#endif /* Decoder_hpp */
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