81 lines
3.2 KiB
C
81 lines
3.2 KiB
C
/*
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operandDefs_6502.h -- Define operand types and flag bits for 6502.
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Chip Morningstar -- Lucasfilm Ltd.
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18-April-1985
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*/
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typedef enum {
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EXPRESSION_OPND, IMMEDIATE_OPND, INDIRECT_OPND,
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A_REGISTER_OPND, X_REGISTER_OPND, Y_REGISTER_OPND,
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POST_INDEXED_Y_OPND, PRE_INDEXED_X_OPND, X_INDEXED_OPND,
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Y_INDEXED_OPND, X_SELECTED_OPND, Y_SELECTED_OPND,
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PRE_SELECTED_X_OPND, STRING_OPND, BLOCK_OPND
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} operandKindType;
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#define operandKindField(op) op
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/* Opcodes: */
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/* In the opcode table we want to have information that tells which possible
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address modes the corresponding instruction can utilize. The
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instruction set of the 6502 breaks up into classes of instructions, such
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that all of the instructions in a class accept the same address modes.
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We encode the instructions by class and the classes by permissible address
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modes. This helps us reduce errors in construction of the opcode table,
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since getting one instruction of a given class right means getting all the
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others right too. */
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typedef enum {
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RELATIVE, DIR_1, DIR_2, DIR_INDIR, DIR_X_1, DIR_X_2, DIR_X_3,
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DIR_Y, IMM_DIR, IMM_DIR_X, IMM_DIR_Y, NONE, INDEX, IMM_INDEX
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} addressClassType;
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#define NO_OPND_BIT 0x0000
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#define EXPRESSION_OPND_BIT 0x0001
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#define IMMEDIATE_OPND_BIT 0x0002
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#define INDIRECT_OPND_BIT 0x0004
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#define A_REGISTER_OPND_BIT 0x0008
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#define X_REGISTER_OPND_BIT 0x0010
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#define Y_REGISTER_OPND_BIT 0x0020
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#define POST_INDEXED_Y_OPND_BIT 0x0040
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#define PRE_INDEXED_X_OPND_BIT 0x0080
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#define X_INDEXED_OPND_BIT 0x0100
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#define Y_INDEXED_OPND_BIT 0x0200
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#define X_SELECTED_OPND_BIT 0x0400
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#define Y_SELECTED_OPND_BIT 0x0800
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#define PRE_SELECTED_X_OPND_BIT 0x1000
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#define STRING_OPND_BIT 0x2000
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#define BLOCK_OPND_BIT 0x4000
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#define ANY_OPND_BITS 0xFFFF
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#define REL_CLASS_BITS EXPRESSION_OPND_BIT
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#define DIR_1_CLASS_BITS EXPRESSION_OPND_BIT
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#define DIR_2_CLASS_BITS EXPRESSION_OPND_BIT
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#define DIR_INDIR_CLASS_BITS EXPRESSION_OPND_BIT | INDIRECT_OPND_BIT
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#define DIR_X_1_CLASS_BITS EXPRESSION_OPND_BIT | X_INDEXED_OPND_BIT | \
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X_SELECTED_OPND_BIT | A_REGISTER_OPND_BIT
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#define DIR_X_2_CLASS_BITS EXPRESSION_OPND_BIT | X_INDEXED_OPND_BIT | \
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X_SELECTED_OPND_BIT
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#define DIR_X_3_CLASS_BITS EXPRESSION_OPND_BIT | X_INDEXED_OPND_BIT | \
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X_SELECTED_OPND_BIT
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#define DIR_Y_CLASS_BITS EXPRESSION_OPND_BIT | Y_INDEXED_OPND_BIT | \
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Y_SELECTED_OPND_BIT
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#define IMM_DIR_CLASS_BITS EXPRESSION_OPND_BIT | IMMEDIATE_OPND_BIT
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#define IMM_DIR_X_CLASS_BITS EXPRESSION_OPND_BIT | IMMEDIATE_OPND_BIT | \
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X_INDEXED_OPND_BIT | X_SELECTED_OPND_BIT
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#define IMM_DIR_Y_CLASS_BITS EXPRESSION_OPND_BIT | IMMEDIATE_OPND_BIT | \
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Y_INDEXED_OPND_BIT | Y_SELECTED_OPND_BIT
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#define NONE_CLASS_BITS NO_OPND_BIT
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#define IMM_INDEX_CLASS_BITS X_INDEXED_OPND_BIT | Y_INDEXED_OPND_BIT | \
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X_SELECTED_OPND_BIT | Y_SELECTED_OPND_BIT | \
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IMMEDIATE_OPND_BIT | PRE_INDEXED_X_OPND_BIT |\
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POST_INDEXED_Y_OPND_BIT | \
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EXPRESSION_OPND_BIT | PRE_SELECTED_X_OPND_BIT
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#define INDEX_CLASS_BITS X_INDEXED_OPND_BIT | Y_INDEXED_OPND_BIT | \
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X_SELECTED_OPND_BIT | Y_SELECTED_OPND_BIT | \
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PRE_INDEXED_X_OPND_BIT | \
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POST_INDEXED_Y_OPND_BIT | \
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EXPRESSION_OPND_BIT | PRE_SELECTED_X_OPND_BIT
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#define MAX_NUMBER_OF_OPERANDS 1
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