mirror of https://github.com/trudnai/Steve2.git
100 lines
2.2 KiB
C
100 lines
2.2 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_STACK_H__
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#define __6502_INSTR_STACK_H__
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static const uint16_t stack_base_addr = 0x100;
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INLINE void PUSH( uint8_t src ) {
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RAM[ stack_base_addr | m6502.SP-- ] = src;
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}
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INLINE uint8_t POP() {
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return RAM[ stack_base_addr | ++m6502.SP ];
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}
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INLINE void PUSH_addr( uint16_t addr ) {
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PUSH( (uint8_t)(addr >> 8) );
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PUSH( (uint8_t)addr );
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}
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INLINE uint16_t POP_addr() {
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return POP() + ( POP() << 8 );
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}
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/**
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PHA Push Accumulator on Stack
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push A 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 PHA 48 1 3
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**/
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INLINE void PHA() {
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dbgPrintf("PHA %02X ", m6502.A);
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disPrintf(disassembly.inst, "PHA");
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PUSH( m6502.A );
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}
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/**
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PLA Pull Accumulator from Stack
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pull A 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 PLA 68 1 4
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**/
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INLINE void PLA() {
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m6502.A = POP();
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dbgPrintf("PLA %02X ", m6502.A);
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disPrintf(disassembly.inst, "PLA");
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set_flags_NZ( m6502.A );
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}
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/**
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PHP Push Processor Status on Stack
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push SR 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 PHP 08 1 3
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**/
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INLINE void PHP() {
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dbgPrintf("PHP %02X ", m6502.SR);
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disPrintf(disassembly.inst, "PHP");
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PUSH( m6502.SR ); // res and B flag should be set
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}
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/**
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PLP Pull Processor Status from Stack
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pull SR N Z C I D V
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from stack
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addressing assembler opc bytes cyles
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--------------------------------------------
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implied PLP 28 1 4
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**/
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INLINE void PLP() {
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m6502.SR = POP() | 0x30; // res and B flag should be set
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dbgPrintf("PLP %02X ", m6502.SR);
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disPrintf(disassembly.inst, "PLP");
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}
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#endif // __6502_INSTR_STACK_H__
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