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117 lines
2.6 KiB
C
117 lines
2.6 KiB
C
//
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// main.c
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// 6502
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//
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// Created by Tamas Rudnai on 7/14/19.
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// Copyright © 2019 GameAlloy. All rights reserved.
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//
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#ifndef __6502_INSTR_INC_DEC_H__
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#define __6502_INSTR_INC_DEC_H__
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/**
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INC Increment Memory by One
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M + 1 -> M N Z C I D V
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+ + - - - -
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addressing assembler opc bytes cyles
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--------------------------------------------
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zeropage INC oper E6 2 5
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zeropage,X INC oper,X F6 2 6
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absolute INC oper EE 3 6
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absolute,X INC oper,X FE 3 7
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**/
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static inline void INC( uint8_t * dst ) {
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dbgPrintf("INC ");
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(*dst)++;
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set_flags_NZ(*dst);
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}
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/**
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INX Increment Index X by One
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X + 1 -> X N Z C I D V
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+ + - - - -
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addressing assembler opc bytes cyles
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--------------------------------------------
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implied INX E8 1 2
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**/
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static inline void INX() {
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dbgPrintf("INX ");
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m6502.X++;
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set_flags_NZ(m6502.X);
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}
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/**
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INY Increment Index Y by One
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Y + 1 -> Y N Z C I D V
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+ + - - - -
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addressing assembler opc bytes cyles
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--------------------------------------------
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implied INY C8 1 2
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**/
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static inline void INY() {
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dbgPrintf("INY %02X -> ", m6502.Y);
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set_flags_NZ(++m6502.Y);
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dbgPrintf("%02X ", m6502.Y);
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}
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/**
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DEC Decrement Memory by One
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M - 1 -> M N Z C I D V
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+ + - - - -
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addressing assembler opc bytes cyles
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--------------------------------------------
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zeropage DEC oper C6 2 5
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zeropage,X DEC oper,X D6 2 6
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absolute DEC oper CE 3 3
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absolute,X DEC oper,X DE 3 7
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**/
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static inline void DEC( uint8_t * dst ) {
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dbgPrintf("DEC ");
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(*dst)--;
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set_flags_NZ(*dst);
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}
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/**
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DEX Decrement Index X by One
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X - 1 -> X N Z C I D V
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+ + - - - -
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addressing assembler opc bytes cyles
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--------------------------------------------
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implied DEC CA 1 2
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**/
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static inline void DEX() {
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dbgPrintf("DEX ");
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m6502.X--;
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set_flags_NZ(m6502.X);
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}
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/**
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DEY Decrement Index Y by One
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Y - 1 -> Y N Z C I D V
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+ + - - - -
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addressing assembler opc bytes cyles
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--------------------------------------------
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implied DEC 88 1 2
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**/
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static inline void DEY() {
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dbgPrintf("DEY ");
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m6502.Y--;
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set_flags_NZ(m6502.Y);
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}
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#endif // __6502_INSTR_INC_DEC_H__
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