mirror of https://github.com/trudnai/Steve2.git
133 lines
3.3 KiB
C
133 lines
3.3 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_SHIFT_ROTATE_H__
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#define __6502_INSTR_SHIFT_ROTATE_H__
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/**
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ASL Shift Left One Bit (Memory or Accumulator)
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C <- [76543210] <- 0 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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accumulator ASL A 0A 1 2
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zeropage ASL oper 06 2 5
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zeropage,X ASL oper,X 16 2 6
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absolute ASL oper 0E 3 6
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absolute,X ASL oper,X 1E 3 7
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**/
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static inline void ASL( uint8_t * dst ) {
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dbgPrintf("ASL ");
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m6502.flags.C = *dst >> 7;
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;
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set_flags_NZ( *dst <<= 1 );
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}
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static inline void ASLA() {
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dbgPrintf("ASL ");
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m6502.flags.C = m6502.A >> 7;
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;
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set_flags_NZ( m6502.A <<= 1 );
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}
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/**
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LSR Shift One Bit Right (Memory or Accumulator)
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0 -> [76543210] -> C N Z C I D V
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0 + + - - -
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addressing assembler opc bytes cyles
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--------------------------------------------
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accumulator LSR A 4A 1 2
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zeropage LSR oper 46 2 5
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zeropage,X LSR oper,X 56 2 6
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absolute LSR oper 4E 3 6
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absolute,X LSR oper,X 5E 3 7
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**/
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static inline void LSR( uint8_t * dst ) {
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dbgPrintf("LSR ");
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m6502.flags.C = *dst & 1;
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;
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set_flags_NZ( *dst >>= 1 );
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}
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static inline void LSRA() {
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dbgPrintf("LSR ");
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m6502.flags.C = m6502.A & 1;
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;
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set_flags_NZ( m6502.A >>= 1 );
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}
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/**
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ROL Rotate One Bit Left (Memory or Accumulator)
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C <- [76543210] <- C 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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accumulator ROL A 2A 1 2
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zeropage ROL oper 26 2 5
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zeropage,X ROL oper,X 36 2 6
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absolute ROL oper 2E 3 6
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absolute,X ROL oper,X 3E 3 7
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**/
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static inline void ROL( uint8_t * dst ) {
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dbgPrintf("ROL ");
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uint8_t C = m6502.flags.C;
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m6502.flags.C = *dst >> 7;
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*dst <<= 1;
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;
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set_flags_NZ( *dst |= C );
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}
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static inline void ROLA() {
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dbgPrintf("ROL ");
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uint8_t C = m6502.flags.C;
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m6502.flags.C = m6502.A >> 7;
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m6502.A <<= 1;
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;
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set_flags_NZ( m6502.A |= C );
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}
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/**
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ROR Rotate One Bit Right (Memory or Accumulator)
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C -> [76543210] -> C 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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accumulator ROR A 6A 1 2
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zeropage ROR oper 66 2 5
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zeropage,X ROR oper,X 76 2 6
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absolute ROR oper 6E 3 6
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absolute,X ROR oper,X 7E 3 7
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**/
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static inline void ROR( uint8_t * dst ) {
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dbgPrintf("ROR ");
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uint8_t C = m6502.flags.C << 7;
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m6502.flags.C = *dst & 1;
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*dst >>= 1;
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;
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set_flags_NZ( *dst |= C );
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}
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static inline void RORA() {
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dbgPrintf("ROR ");
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uint8_t C = m6502.flags.C << 7;
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m6502.flags.C = m6502.A & 1;
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m6502.A >>= 1;
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;
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set_flags_NZ( m6502.A |= C );
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}
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#endif // __6502_INSTR_SHIFT_ROTATE_H__
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