INCLUDE equates.s INCLUDE 6502mac.s IMPORT NES_RAM ;nes_main.c __align(1024) uint8 NES_RAM[0x800];//保持1024字节对齐 IMPORT NES_SRAM ;nes_main.c uint8 NES_SRAM[0x2000]; IMPORT spr_ram ; uint8 spr_ram[0x100]; EXPORT cpunmi ;cpu中断标志 EXPORT cpuirq ;cpu中断标志 EXPORT clocks ;apu要的cpu时钟 EXPORT cpu_data ;地址 cart.s EXPORT NMI6502 EXPORT CPU_reset EXPORT run6502 EXPORT op_table IRQ_VECTOR EQU 0xfffe ; //IRQ / BRK中断向量地址 RES_VECTOR EQU 0xfffc ;// 复位中断向量地址 NMI_VECTOR EQU 0xfffa ;// NMI中断向量地址 ;cycle flags- (stored in cycles reg for speed)存储在周期章速度 CYC_C EQU 0x01 ;Carry bit 进位 ;BRANCH EQU 0x02 ;branch instruction encountered 遇到分支指令 CYC_I EQU 0x04 ;IRQ mask CYC_D EQU 0x08 ;Decimal bit 小数位 CYC_V EQU 0x40 ;Overflow bit 溢出位 ;CYC_MASK EQU 0xFF;CYCLE-1 ;Mask AREA cpu_code, CODE, READONLY ;, ALIGN=2 ; 不要对 ARM 代码节使用 ALIGN=0 或 ALIGN=1。 ; 不要对 Thumb 代码节使用 ALIGN=0。 ;AREA 伪代码也是需要语法的，AREA 后面跟着段名标号，然后是属性，CODE 表示这是一 ;个代码段，READONLY 表示这个段是只读的 ;|.text|系统默认的代码段名 ; ALIGN 指令通过用零或 NOP 指令进行填充将当前位置对齐到指定边界 ;ENTRY 这个伪代码是用来定义入口点 THUMB ;Thumb是ARM体系结构中一种16位的指令集 ; REQUIRE8 ;REQUIRE8 指令指定当前文件要求堆栈八字节对齐。 它设置 REQ8 编译属性以通知链接器。 PRESERVE8 ;{TRUE} ;PRESERVE8 指令指定当前文件保持堆栈八字节对齐。 它设置 PRES8 编译属性以通知链接器。 ;如果您省略 PRESERVE8 和 PRESERVE8 {FALSE}，汇编程序会检查修改 sp 的指令， ;以决定是否设置 PRES8 编译属性。 ARM 建议明确指定 PRESERVE8。 ; ARM使用r0作为返回值 ;参数传递ARM：寄存器到堆栈，首先将参数赋给r0, r1等 ; PROC 为子程序开始，ENDP 为子程序结束 ;r0,r1,r2=temp regs m6502_nz RN r3 ;bit 31=N, Z=1 if bits 0-7=0 ;RN定义寄存器名 m6502_rmem RN r4 ;readmem_tbl m6502_a RN r5 ;//bits 0-23=0, 还用于清除在内存中的字节 m6502_x RN r6 ;bits 0-23=0 m6502_y RN r7 ;bits 0-23=0 cycles RN r8 ;//also VDIC flags也VDIC标志 m6502_pc RN r9 globalptr RN r10 ;=wram_globals* ptr m6502_optbl RN r10 cpu_zpage RN r11 ;=CPU_RAM addy RN r12 ;//keep this at r12 (从头 APCS) //addr :代表8位地址 ;r13=SP ;r14=LR ;r15=PC ;--------------------------------------------------- _00; BRK ;---------------------------------------------------------------------------- ldr r0,lastbank ; 6502PC从 ROM的最后偏移量 sub r1,m6502_pc,r0 add r0,r1,#1 push16 ;save PC encodeP (B+R) ;save P ldr r12,=IRQ_VECTOR bl VecCont fetch 7 LTORG ;指令， LTORG可能是在一个可执行的位置 ;---------------------------------------------------------------------------- _01; ORA ($nn,X) ;---------------------------------------------------------------------------- doIIX opORA fetch 6 ;---------------------------------------------------------------------------- _05; ORA $nn ;---------------------------------------------------------------------------- doZ opORA fetch 3 ;---------------------------------------------------------------------------- _06; ASL $nn ;---------------------------------------------------------------------------- doZ opASL fetch_c 5 ;---------------------------------------------------------------------------- _08; PHP ;---------------------------------------------------------------------------- encodeP (B+R) push8 r0 fetch 3 ;---------------------------------------------------------------------------- _09; ORA #$nn ;---------------------------------------------------------------------------- doIMM opORA fetch 2 ;---------------------------------------------------------------------------- _0A; ASL ;---------------------------------------------------------------------------- adds m6502_a,m6502_a,m6502_a mov m6502_nz,m6502_a,asr#24 ;NZ orr cycles,cycles,#CYC_C ;Prepare C fetch_c 2 ;also subs carry ;---------------------------------------------------------------------------- _0D; ORA $nnnn ;---------------------------------------------------------------------------- doABS opORA fetch 4 ;---------------------------------------------------------------------------- _0E; ASL $nnnn ;---------------------------------------------------------------------------- doABS opASL fetch_c 6 ;---------------------------------------------------------------------------- _10; BPL * ;---------------------------------------------------------------------------- tst m6502_nz,#0x80000000 ldrsb r0,[m6502_pc],#1 addeq m6502_pc,m6502_pc,r0 ; subeq cycles,cycles,#3*CYCLE subeq cycles,cycles,#256 fetch 2 ;---------------------------------------------------------------------------- _11; ORA ($nn),Y ;---------------------------------------------------------------------------- doIIY opORA fetch 5 ;---------------------------------------------------------------------------- _15; ORA $nn,X ;---------------------------------------------------------------------------- doZIXf opORA fetch 4 ;---------------------------------------------------------------------------- _16; ASL $nn,X ;---------------------------------------------------------------------------- doZIXf opASL fetch_c 6 ;---------------------------------------------------------------------------- _18; CLC ;---------------------------------------------------------------------------- bic cycles,cycles,#CYC_C fetch 2 ;---------------------------------------------------------------------------- _19; ORA $nnnn,Y ;---------------------------------------------------------------------------- doAIY opORA fetch 4 ;---------------------------------------------------------------------------- _1D; ORA $nnnn,X ;---------------------------------------------------------------------------- doAIX opORA fetch 4 ;---------------------------------------------------------------------------- _1E; ASL $nnnn,X ;---------------------------------------------------------------------------- doAIX opASL fetch_c 7 ;---------------------------------------------------------------------------- _20; JSR $nnnn ;---------------------------------------------------------------------------- ldrb r2,[m6502_pc],#1 ldr r1,lastbank sub r0,m6502_pc,r1 ldrb r1,[m6502_pc] orr m6502_pc,r2,r1,lsl#8 push16 encodePC fetch 6 ;---------------------------------------------------------------------------- _21; AND ($nn,X) ;---------------------------------------------------------------------------- doIIX opAND fetch 6 ;---------------------------------------------------------------------------- _24; BIT $nn ;---------------------------------------------------------------------------- doZ opBIT fetch 3 ;---------------------------------------------------------------------------- _25; AND $nn ;---------------------------------------------------------------------------- doZ opAND fetch 3 ;---------------------------------------------------------------------------- _26; ROL $nn ;---------------------------------------------------------------------------- doZ opROL fetch 5 ;---------------------------------------------------------------------------- _28; PLP ;---------------------------------------------------------------------------- pop8 r0 decodeP fetch 4 ;---------------------------------------------------------------------------- _29; AND #$nn ;---------------------------------------------------------------------------- doIMM opAND fetch 2 ;---------------------------------------------------------------------------- _2A; ROL ;---------------------------------------------------------------------------- movs cycles,cycles,lsr#1 ;get C orrcs m6502_a,m6502_a,#0x00800000 adds m6502_a,m6502_a,m6502_a mov m6502_nz,m6502_a,asr#24 ;NZ adc cycles,cycles,cycles ;Set C fetch 2 ;---------------------------------------------------------------------------- _2C; BIT $nnnn ;---------------------------------------------------------------------------- doABS opBIT fetch 4 ;---------------------------------------------------------------------------- _2D; AND $nnnn ;---------------------------------------------------------------------------- doABS opAND fetch 4 ;---------------------------------------------------------------------------- _2E; ROL $nnnn ;---------------------------------------------------------------------------- doABS opROL fetch 6 ;---------------------------------------------------------------------------- _30; BMI * ;---------------------------------------------------------------------------- tst m6502_nz,#0x80000000 ldrsb r0,[m6502_pc],#1 addne m6502_pc,m6502_pc,r0 ; subne cycles,cycles,#3*CYCLE subne cycles,cycles,#256 fetch 2 ;---------------------------------------------------------------------------- _31; AND ($nn),Y ;---------------------------------------------------------------------------- doIIY opAND fetch 5 ;---------------------------------------------------------------------------- _35; AND $nn,X ;---------------------------------------------------------------------------- doZIXf opAND fetch 4 ;---------------------------------------------------------------------------- _36; ROL $nn,X ;---------------------------------------------------------------------------- doZIXf opROL fetch 6 ;---------------------------------------------------------------------------- _38; SEC ;---------------------------------------------------------------------------- orr cycles,cycles,#CYC_C fetch 2 ;---------------------------------------------------------------------------- _39; AND $nnnn,Y ;---------------------------------------------------------------------------- doAIY opAND fetch 4 ;---------------------------------------------------------------------------- _3D; AND $nnnn,X ;---------------------------------------------------------------------------- doAIX opAND fetch 4 ;---------------------------------------------------------------------------- _3E; ROL $nnnn,X ;---------------------------------------------------------------------------- doAIX opROL fetch 7 ;---------------------------------------------------------------------------- _40; RTI ;---------------------------------------------------------------------------- pop8 r0 ;pop 6502 flags and decode decodeP pop16 ;pop the return address encodePC fetch 6 ;---------------------------------------------------------------------------- _41; EOR ($nn,X) ;---------------------------------------------------------------------------- doIIX opEOR fetch 6 ;---------------------------------------------------------------------------- _45; EOR $nn ;---------------------------------------------------------------------------- doZ opEOR fetch 3 ;---------------------------------------------------------------------------- _46; LSR $nn ;---------------------------------------------------------------------------- doZ opLSR fetch_c 5 ;---------------------------------------------------------------------------- _48; PHA ;---------------------------------------------------------------------------- mov r0,m6502_a,lsr#24 push8 r0 fetch 3 ;---------------------------------------------------------------------------- _49; EOR #$nn ;---------------------------------------------------------------------------- doIMM opEOR fetch 2 ;---------------------------------------------------------------------------- _4A; LSR ;---------------------------------------------------------------------------- movs m6502_nz,m6502_a,lsr#25 ;Z, N=0 mov m6502_a,m6502_nz,lsl#24 ;result without garbage orr cycles,cycles,#CYC_C ;Prepare C fetch_c 2 ;---------------------------------------------------------------------------- _4C; JMP $nnnn ;---------------------------------------------------------------------------- ldrb r0,[m6502_pc],#1 ldrb r1,[m6502_pc] orr m6502_pc,r0,r1,lsl#8 encodePC fetch 3 ;---------------------------------------------------------------------------- _4D; EOR $nnnn ;---------------------------------------------------------------------------- doABS opEOR fetch 4 ;---------------------------------------------------------------------------- _4E; LSR $nnnn ;---------------------------------------------------------------------------- doABS opLSR fetch_c 6 ;---------------------------------------------------------------------------- _50; BVC * ;---------------------------------------------------------------------------- tst cycles,#CYC_V ldrsb r0,[m6502_pc],#1 addeq m6502_pc,m6502_pc,r0 ; subeq cycles,cycles,#3*CYCLE subeq cycles,cycles,#256 fetch 2 ;---------------------------------------------------------------------------- _51; EOR ($nn),Y ;---------------------------------------------------------------------------- doIIY opEOR fetch 5 ;---------------------------------------------------------------------------- _55; EOR $nn,X ;---------------------------------------------------------------------------- doZIXf opEOR fetch 4 ;---------------------------------------------------------------------------- _56; LSR $nn,X ;---------------------------------------------------------------------------- doZIXf opLSR fetch_c 6 ;---------------------------------------------------------------------------- _58; CLI ;---------------------------------------------------------------------------- bic cycles,cycles,#CYC_I fetch 2 ;---------------------------------------------------------------------------- _59; EOR $nnnn,Y ;---------------------------------------------------------------------------- doAIY opEOR fetch 4 ;---------------------------------------------------------------------------- _5D; EOR $nnnn,X ;---------------------------------------------------------------------------- doAIX opEOR fetch 4 ;---------------------------------------------------------------------------- _5E; LSR $nnnn,X ;---------------------------------------------------------------------------- doAIX opLSR fetch_c 7 ;---------------------------------------------------------------------------- _60; RTS ;---------------------------------------------------------------------------- pop16 add m6502_pc,m6502_pc,#1 encodePC fetch 6 ;---------------------------------------------------------------------------- _61; ADC ($nn,X) ;---------------------------------------------------------------------------- doIIX opADC fetch_c 6 ;---------------------------------------------------------------------------- _65; ADC $nn ;---------------------------------------------------------------------------- doZ opADC fetch_c 3 ;---------------------------------------------------------------------------- _66; ROR $nn ;---------------------------------------------------------------------------- doZ opROR fetch 5 ;---------------------------------------------------------------------------- _68; PLA ;---------------------------------------------------------------------------- pop8 m6502_nz mov m6502_a,m6502_nz,lsl#24 fetch 4 ;---------------------------------------------------------------------------- _69; ADC #$nn ;---------------------------------------------------------------------------- doIMM opADC fetch_c 2 ;---------------------------------------------------------------------------- _6A; ROR ;---------------------------------------------------------------------------- movs cycles,cycles,lsr#1 ;get C mov m6502_a,m6502_a,rrx movs m6502_nz,m6502_a,asr#24 ;NZ and m6502_a,m6502_a,#0xff000000 adc cycles,cycles,cycles ;Set C fetch 2 ;---------------------------------------------------------------------------- _6C; JMP ($nnnn) JMP ($data16) 间接寻址 ********************************* ;---------------------------------------------------------------------------- doABS adr r1,memmap_tbl and r2,addy,#0xE000 ; ; ldr r1,[r1,r2,lsr#11] ;>>11 addr&0x7FF lsr r0,r2,#11 ldr r1,[r1,r0] ;在数据传送之前,将偏移量加到Rn 中,其结果作为传送数据的存储地址 ldrb m6502_pc,[r1,addy] ;//若使用后缀"!",则结果写回到Rn中 add r1,r1,addy ldrb r0,[r1,#1] orr m6502_pc,m6502_pc,r0,lsl#8 ;m6502_pc=r9使用ORR 指令将近R9的高8 位数据移入到R0低8位 encodePC fetch 5 ;---------------------------------------------------------------------------- _6D; ADC $nnnn ;---------------------------------------------------------------------------- doABS opADC fetch_c 4 ;---------------------------------------------------------------------------- _6E; ROR $nnnn ;---------------------------------------------------------------------------- doABS opROR fetch 6 ;---------------------------------------------------------------------------- _70; BVS * ;---------------------------------------------------------------------------- tst cycles,#CYC_V ldrsb r0,[m6502_pc],#1 addne m6502_pc,m6502_pc,r0 ; subne cycles,cycles,#3*CYCLE subne cycles,cycles,#256 fetch 2 ;---------------------------------------------------------------------------- _71; ADC ($nn),Y ;---------------------------------------------------------------------------- doIIY opADC fetch_c 5 ;---------------------------------------------------------------------------- _75; ADC $nn,X ;---------------------------------------------------------------------------- doZIXf opADC fetch_c 4 ;---------------------------------------------------------------------------- _76; ROR $nn,X ;---------------------------------------------------------------------------- doZIXf opROR fetch 6 ;---------------------------------------------------------------------------- _78; SEI ;---------------------------------------------------------------------------- orr cycles,cycles,#CYC_I fetch 2 ;---------------------------------------------------------------------------- _79; ADC $nnnn,Y ;---------------------------------------------------------------------------- doAIY opADC fetch_c 4 ;---------------------------------------------------------------------------- _7D; ADC $nnnn,X ;---------------------------------------------------------------------------- doAIX opADC fetch_c 4 ;---------------------------------------------------------------------------- _7E; ROR $nnnn,X ;---------------------------------------------------------------------------- doAIX opROR fetch 7 ;---------------------------------------------------------------------------- _81; STA ($nn,X) ;---------------------------------------------------------------------------- doIIX opSTORE m6502_a fetch 6 ;---------------------------------------------------------------------------- _84; STY $nn ;---------------------------------------------------------------------------- doZ opSTORE m6502_y fetch 3 ;---------------------------------------------------------------------------- _85; STA $nn ;---------------------------------------------------------------------------- doZ opSTORE m6502_a fetch 3 ;---------------------------------------------------------------------------- _86; STX $nn ;---------------------------------------------------------------------------- doZ opSTORE m6502_x fetch 3 ;---------------------------------------------------------------------------- _88; DEY ;---------------------------------------------------------------------------- sub m6502_y,m6502_y,#0x01000000 mov m6502_nz,m6502_y,asr#24 fetch 2 ;---------------------------------------------------------------------------- _8A; TXA ;---------------------------------------------------------------------------- mov m6502_a,m6502_x mov m6502_nz,m6502_x,asr#24 fetch 2 ;---------------------------------------------------------------------------- _8C; STY $nnnn ;---------------------------------------------------------------------------- doABS opSTORE m6502_y fetch 4 ;---------------------------------------------------------------------------- _8D; STA $nnnn ;---------------------------------------------------------------------------- doABS opSTORE m6502_a fetch 4 ;---------------------------------------------------------------------------- _8E; STX $nnnn ;---------------------------------------------------------------------------- doABS opSTORE m6502_x fetch 4 ;---------------------------------------------------------------------------- _90; BCC * ;---------------------------------------------------------------------------- tst cycles,#CYC_C ;Test Carry ldrsb r0,[m6502_pc],#1 addeq m6502_pc,m6502_pc,r0 ; subeq cycles,cycles,#3*CYCLE subeq cycles,cycles,#256 fetch 2 ;---------------------------------------------------------------------------- _91; STA ($nn),Y ;---------------------------------------------------------------------------- doIIY opSTORE m6502_a fetch 6 ;---------------------------------------------------------------------------- _94; STY $nn,X ;---------------------------------------------------------------------------- doZIXf opSTORE m6502_y fetch 4 ;---------------------------------------------------------------------------- _95; STA $nn,X ;---------------------------------------------------------------------------- doZIXf opSTORE m6502_a fetch 4 ;---------------------------------------------------------------------------- _96; STX $nn,Y ;---------------------------------------------------------------------------- doZIYf opSTORE m6502_x fetch 4 ;---------------------------------------------------------------------------- _98; TYA ;---------------------------------------------------------------------------- mov m6502_a,m6502_y mov m6502_nz,m6502_y,asr#24 fetch 2 ;---------------------------------------------------------------------------- _99; STA $nnnn,Y ;---------------------------------------------------------------------------- doAIY opSTORE m6502_a fetch 5 ;---------------------------------------------------------------------------- _9A; TXS ;---------------------------------------------------------------------------- mov r0,m6502_x,lsr#24 strb r0,m6502_s fetch 2 ;---------------------------------------------------------------------------- _9D; STA $nnnn,X ;---------------------------------------------------------------------------- doAIX opSTORE m6502_a fetch 5 ;---------------------------------------------------------------------------- _A0; LDY #$nn ;---------------------------------------------------------------------------- doIMM opLOAD m6502_y fetch 2 ;---------------------------------------------------------------------------- _A1; LDA ($nn,X) ;---------------------------------------------------------------------------- doIIX opLOAD m6502_a fetch 6 ;---------------------------------------------------------------------------- _A2; LDX #$nn ;---------------------------------------------------------------------------- doIMM opLOAD m6502_x fetch 2 ;---------------------------------------------------------------------------- _A4; LDY $nn ;---------------------------------------------------------------------------- doZ opLOAD m6502_y fetch 3 ;---------------------------------------------------------------------------- _A5; LDA $nn ;---------------------------------------------------------------------------- doZ opLOAD m6502_a fetch 3 ;---------------------------------------------------------------------------- _A6; LDX $nn ;---------------------------------------------------------------------------- doZ opLOAD m6502_x fetch 3 ;---------------------------------------------------------------------------- _A8; TAY ;---------------------------------------------------------------------------- mov m6502_y,m6502_a mov m6502_nz,m6502_y,asr#24 fetch 2 ;---------------------------------------------------------------------------- _A9; LDA #$nn ;---------------------------------------------------------------------------- doIMM opLOAD m6502_a fetch 2 ;---------------------------------------------------------------------------- _AA; TAX ;---------------------------------------------------------------------------- mov m6502_x,m6502_a mov m6502_nz,m6502_x,asr#24 fetch 2 ;---------------------------------------------------------------------------- _AC; LDY $nnnn ;---------------------------------------------------------------------------- doABS opLOAD m6502_y fetch 4 ;---------------------------------------------------------------------------- _AD; LDA $nnnn ;---------------------------------------------------------------------------- doABS opLOAD m6502_a fetch 4 ;---------------------------------------------------------------------------- _AE; LDX $nnnn ;---------------------------------------------------------------------------- doABS opLOAD m6502_x fetch 4 ;---------------------------------------------------------------------------- _B0; BCS * ;---------------------------------------------------------------------------- tst cycles,#CYC_C ;Test Carry ldrsb r0,[m6502_pc],#1 addne m6502_pc,m6502_pc,r0 ; subne cycles,cycles,#3*CYCLE subne cycles,cycles,#256 fetch 2 ;---------------------------------------------------------------------------- _B1; LDA ($nn),Y ;---------------------------------------------------------------------------- doIIY opLOAD m6502_a fetch 5 ;---------------------------------------------------------------------------- _B4; LDY $nn,X ;---------------------------------------------------------------------------- doZIX opLOAD m6502_y fetch 4 ;---------------------------------------------------------------------------- _B5; LDA $nn,X ;---------------------------------------------------------------------------- doZIX opLOAD m6502_a fetch 4 ;---------------------------------------------------------------------------- _B6; LDX $nn,Y ;---------------------------------------------------------------------------- doZIY opLOAD m6502_x fetch 4 ;---------------------------------------------------------------------------- _B8; CLV ;---------------------------------------------------------------------------- bic cycles,cycles,#CYC_V fetch 2 ;---------------------------------------------------------------------------- _B9; LDA $nnnn,Y ;---------------------------------------------------------------------------- doAIY opLOAD m6502_a fetch 4 ;---------------------------------------------------------------------------- _BA; TSX ;---------------------------------------------------------------------------- ldrb m6502_x,m6502_s mov m6502_x,m6502_x,lsl#24 mov m6502_nz,m6502_x,asr#24 fetch 2 ;---------------------------------------------------------------------------- _BC; LDY $nnnn,X ;---------------------------------------------------------------------------- doAIX opLOAD m6502_y fetch 4 ;---------------------------------------------------------------------------- _BD; LDA $nnnn,X ;---------------------------------------------------------------------------- doAIX opLOAD m6502_a fetch 4 ;---------------------------------------------------------------------------- _BE; LDX $nnnn,Y ;---------------------------------------------------------------------------- doAIY opLOAD m6502_x fetch 4 ;---------------------------------------------------------------------------- _C0; CPY #$nn ;---------------------------------------------------------------------------- doIMM opCOMP m6502_y fetch_c 2 ;---------------------------------------------------------------------------- _C1; CMP ($nn,X) ;---------------------------------------------------------------------------- doIIX opCOMP m6502_a fetch_c 6 ;---------------------------------------------------------------------------- _C4; CPY $nn ;---------------------------------------------------------------------------- doZ opCOMP m6502_y fetch_c 3 ;---------------------------------------------------------------------------- _C5; CMP $nn ;---------------------------------------------------------------------------- doZ opCOMP m6502_a fetch_c 3 ;---------------------------------------------------------------------------- _C6; DEC $nn ;---------------------------------------------------------------------------- doZ opDEC fetch 5 ;---------------------------------------------------------------------------- _C8; INY ;---------------------------------------------------------------------------- add m6502_y,m6502_y,#0x01000000 mov m6502_nz,m6502_y,asr#24 fetch 2 ;---------------------------------------------------------------------------- _C9; CMP #$nn ;---------------------------------------------------------------------------- doIMM opCOMP m6502_a fetch_c 2 ;---------------------------------------------------------------------------- _CA; DEX ;---------------------------------------------------------------------------- sub m6502_x,m6502_x,#0x01000000 mov m6502_nz,m6502_x,asr#24 fetch 2 ;---------------------------------------------------------------------------- _CC; CPY $nnnn ;---------------------------------------------------------------------------- doABS opCOMP m6502_y fetch_c 4 ;---------------------------------------------------------------------------- _CD; CMP $nnnn ;---------------------------------------------------------------------------- doABS opCOMP m6502_a fetch_c 4 ;---------------------------------------------------------------------------- _CE; DEC $nnnn ;---------------------------------------------------------------------------- doABS opDEC fetch 6 ;---------------------------------------------------------------------------- _D0; BNE * ;---------------------------------------------------------------------------- tst m6502_nz,#0xff ldrsb r0,[m6502_pc],#1 addne m6502_pc,m6502_pc,r0 ; subne cycles,cycles,#3*CYCLE subne cycles,cycles,#256 fetch 2 ;---------------------------------------------------------------------------- _D1; CMP ($nn),Y ;---------------------------------------------------------------------------- doIIY opCOMP m6502_a fetch_c 5 ;---------------------------------------------------------------------------- _D5; CMP $nn,X ;---------------------------------------------------------------------------- doZIXf opCOMP m6502_a fetch_c 4 ;---------------------------------------------------------------------------- _D6; DEC $nn,X ;---------------------------------------------------------------------------- doZIXf opDEC fetch 6 ;---------------------------------------------------------------------------- _D8; CLD ;---------------------------------------------------------------------------- bic cycles,cycles,#CYC_D fetch 2 ;---------------------------------------------------------------------------- _D9; CMP $nnnn,Y ;---------------------------------------------------------------------------- doAIY opCOMP m6502_a fetch_c 4 ;---------------------------------------------------------------------------- _DD; CMP $nnnn,X ;---------------------------------------------------------------------------- doAIX opCOMP m6502_a fetch_c 4 ;---------------------------------------------------------------------------- _DE; DEC $nnnn,X ;---------------------------------------------------------------------------- doAIX opDEC fetch 7 ;---------------------------------------------------------------------------- _E0; CPX #$nn ;---------------------------------------------------------------------------- doIMM opCOMP m6502_x fetch_c 2 ;---------------------------------------------------------------------------- _E1; SBC ($nn,X) ;---------------------------------------------------------------------------- doIIX opSBC fetch_c 6 ;---------------------------------------------------------------------------- _E4; CPX $nn ;---------------------------------------------------------------------------- doZ opCOMP m6502_x fetch_c 3 ;---------------------------------------------------------------------------- _E5; SBC $nn ;---------------------------------------------------------------------------- doZ opSBC fetch_c 3 ;---------------------------------------------------------------------------- _E6; INC $nn ;---------------------------------------------------------------------------- doZ opINC fetch 5 ;---------------------------------------------------------------------------- _E8; INX ;---------------------------------------------------------------------------- add m6502_x,m6502_x,#0x01000000 mov m6502_nz,m6502_x,asr#24 fetch 2 ;---------------------------------------------------------------------------- _E9; SBC #$nn ;---------------------------------------------------------------------------- doIMM opSBC fetch_c 2 ;---------------------------------------------------------------------------- _EA; NOP ;---------------------------------------------------------------------------- fetch 2 ;---------------------------------------------------------------------------- _EC; CPX $nnnn ;---------------------------------------------------------------------------- doABS opCOMP m6502_x fetch_c 4 ;---------------------------------------------------------------------------- _ED; SBC $nnnn ;---------------------------------------------------------------------------- doABS opSBC fetch_c 4 ;---------------------------------------------------------------------------- _EE; INC $nnnn ;---------------------------------------------------------------------------- doABS opINC fetch 6 ;---------------------------------------------------------------------------- _F0; BEQ * ;---------------------------------------------------------------------------- tst m6502_nz,#0xff ldrsb r0,[m6502_pc],#1 addeq m6502_pc,m6502_pc,r0 ; subeq cycles,cycles,#3*CYCLE subeq cycles,cycles,#256 fetch 2 ;---------------------------------------------------------------------------- _F1; SBC ($nn),Y ;---------------------------------------------------------------------------- doIIY opSBC fetch_c 5 ;---------------------------------------------------------------------------- _F5; SBC $nn,X ;---------------------------------------------------------------------------- doZIXf opSBC fetch_c 4 ;---------------------------------------------------------------------------- _F6; INC $nn,X ;---------------------------------------------------------------------------- doZIXf opINC fetch 6 ;---------------------------------------------------------------------------- _F8; SED ;---------------------------------------------------------------------------- orr cycles,cycles,#CYC_D fetch 2 ;---------------------------------------------------------------------------- _F9; SBC $nnnn,Y ;---------------------------------------------------------------------------- doAIY opSBC fetch_c 4 ;---------------------------------------------------------------------------- _FD; SBC $nnnn,X ;---------------------------------------------------------------------------- doAIX opSBC fetch_c 4 ;---------------------------------------------------------------------------- _FE; INC $nnnn,X ;---------------------------------------------------------------------------- doAIX opINC fetch 7 ;***********************************************************以下指令是一些HACK游戏需要****************** _FF; ISB $????,X 加的，不确定正确 激龟忍者传2无敌HACK需要 ;------------------------------------------------------------------- doAIX ;MR_AX(); opSBC ;ISB(); ;MW_EA(); #define MW_EA() WR6502(EA,DT) // EA .... EFFECTIVE ADDRESS fetch 5 ;ADD_CYCLE(5); // DT .... DATA ;------------------------------------------------------------------------ _FB; ISB $????,X 加的，不确定正确 激龟忍者传2无敌HACK需要 ;------------------------------------------------------------------- doAIY ;MR_AY(); opSBC ;ISB(); ;MW_EA(); fetch 5 ;ADD_CYCLE(5); ;------------------------------------------------------------------------ _14; 加的，不确定正确 激龟忍者传2无敌HACK需要 ;------------------------------------------------------------------- add m6502_pc,m6502_pc,#1 ;R.PC++; fetch 4 ;ADD_CYCLE(4); ;------------------------------------------------------------------- _67; // RRA $?? 帝国战机无敌HACK需要 ;------------------------------------------------------------------- doZ ;MR_ZP(); opADC ;RRA(); ;MW_ZP(); fetch 5 ;ADD_CYCLE(5); ;-------------------------------------------------------------------- _03; // SLO ($??,X) 帝国战机无敌HACK需要 ;------------------------------------------------------------------- doIIX ;MR_IX(); ;SLO(); ;MW_EA(); fetch 8; ;ADD_CYCLE(8); ;----------------------------------------------------------------- _07; // SLO $?? ;------------------------------------------------------------------ doZ ;MR_ZP(); ;SLO(); ;MW_ZP(); fetch 5 ;ADD_CYCLE(5); ;---------------------------------------------------------------------------- IMPORT debug_6502 ;main.c _xx; ??? ;invalid opcode 无效的操作码 ;---------------------------------------------------------------------------- mov r1,#1 ;不用debug可以直接注译这两行 bl debug_6502 fetch 2 ;***************************************************************************************************** AREA cpu_run, CODE, READONLY run6502 PROC;r0=要运行的cpu周期*256 ;---------------------------------------------------------------------------- stmfd sp!,{r4-r11,lr} ;将这几个寄存器中的值保存到堆栈中 ldr globalptr,=cpu_data ;r10 wram_globals: 读取地址 ldr cpu_zpage,=NES_RAM ;r11 ldr cpu_zpage,[cpu_zpage] ;NES_RAM用了指针 adr r1,cpuregs ldmia r1,{m6502_nz-m6502_pc} ;restore 6502 state恢复6502状态 r3-r9 add cycles,cycles,r0 ldrb r0,cpuirqf ;cpu中断标志 cmp r0,#0x01; beq CheckI ;EQ 相等(EQual) irq6502; fetch 0 ;//提取操作码并运行 exit_run ldrb r0,cpunmif ;cpu中断标志 cmp r0,#0x01; beq NMI6502 ;EQ 相等(EQual) exit_nmi adr r0,cpuregs stmia r0,{m6502_nz-m6502_pc} ;保存6502状态 r3-r9 ldmfd sp!,{r4-r11,pc} ;exit ENDP ;*************************************************************************************** NMI6502 PROC;--------------------------- mov r0,#0 str r0,cpunmif;清除cpu中断标志 ldr r12,=NMI_VECTOR ;NMI? addy bl Vec6502 sub cycles,cycles,#7*256 ;CYCLE=256 6502的中断潜伏期为七 (7) 个周 ; 期; 这也就是说需要需要七 (7) 个周期来移入和移出一个中断 b exit_nmi ;return ENDP ;---------------------------------------------------------------------------- default_scanlinehook fetch 0 ;---------------------------------------------------------- CheckI ;Check Interrupt Disable 检查中断禁用 ;---------------------------------------------------------- tst cycles,#CYC_I bne default_scanlinehook ;we dont want no stinkin irqs 我们不需要没有讨厌的IRQ ;---------------------------------------------------------- irq6502 ;---------------------------------------------------------- mov r0,#0 str r0,cpuirqf;清除cpu中断标志 ldr r12,=IRQ_VECTOR bl Vec6502 fetch 7 ;---------------------------------------------------------- Vec6502 ;---------------------------------------------------------- ldr r0,lastbank sub r0,m6502_pc,r0 push16 ;save PC encodeP (R) ;save P VecCont push8 r0 orr cycles,cycles,#CYC_I ;disable IRQ 禁用IRQ ldr r0,memmap_tbl+28 ;7*4 ; ldrb m6502_pc,[r0,r12]! ldrb m6502_pc,[r0,r12] ;在数据传送之前,将偏移量加到Rn 中,其结果作为传送数据的存储地址 ;若使用后缀"!",则结果写回到Rn中 add r0,r0,r12 ;R12=0xfffc ;// 复位中断向量地址 ldrb r2,[r0,#1] orr m6502_pc,m6502_pc,r2,lsl#8 encodePC ;get IRQ vector得到6502 PC ROM的偏移量 bx lr ; 函数返回 ;---------------------------------------------------------------------------- CPU_reset PROC ;called by loadcart (r0-r9 are free to use) ;---------------------------------------------------------------------------- str lr,[sp,#-4]! mov m6502_a,#0 mov m6502_x,#0 mov m6502_y,#0 mov m6502_nz,#0 adr m6502_rmem,readmem_tbl ;把readmem_tbl的地址加载到m6502_rmem ; ldr r0,=NES_RAM+0x100 ;256 ldr r0,=NES_RAM ;NES_RAM用了指针 ldr r0,[r0] ; add r0,#0x100 str r0,m6502_s ;S=0xFD (0x100-3) 把一个寄存器按字存储到存储器中 ;------------------------------------------------------- mov r0,#0 str r0,cpunmif;清除cpu中断标志 str r0,cpuirqf ;清除cpu中断标志 ;------------------------------------------ mov cycles,#0 ;D=0, C=0, V=0, I=1 disable IRQ. ldr r12,=RES_VECTOR ;// 复位中断向量地址 bl Vec6502 adr r0,cpuregs ;读取地址 stmia r0,{m6502_nz-m6502_pc} ;保存6502状态 ldr r1,=exit_run ; str r1,nexttimeout ;保存指令执行完后下一步的PC地址 ldr pc,[sp],#4 ENDP ; nop ;------------------------------------------------------------------------- AREA rwram_code, CODE, READONLY;READWRITE************************************** ;---------------------------------------------------------------------------- ;memory ;------------------------------------------------------------------------ empty_R ;读地址不正确read bad address (error) ;---------------------------------------------------------------------------- mov r0,r12 mov r1,#2 bl debug_6502 ;---------------------------------- mov r0,#0 orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- void PROC;- - - - - - - - -空函数 mov r0,#0 orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ENDP ;---------------------------------------------------------------------------- ram_R ;ram read ($0000-$1FFF) ;---------------------------------------------------------------------------- bic addy,addy,#0x1f800 ;only 0x07FF is RAM ldrb r0,[cpu_zpage,addy] orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- ram_W ;ram write ($0000-$1FFF) ;---------------------------------------------------------------------------- bic addy,addy,#0x1f800 ;only 0x07FF is RAM strb r0,[cpu_zpage,addy] ; cpu_zpage RN r11 ;=CPU_RAM orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- sram_R ;sram read ($6000-$7FFF) ;---------------------------------------------------------------------------- sub r1,addy,#0x6000 ldr r2,memmap_tbl+12 ; ldrb r0,[cpu_zpage,r1] ldrb r0,[r2,r1] orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- sram_W ;sram write ($6000-$7FFF) ;---------------------------------------------------------------------------- sub addy,addy,#0x6000 ldr r1,memmap_tbl+12 ; strb r0,[cpu_zpage,addy] strb r0,[r1,addy] orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- rom_R60 ;rom read ($6000-$7FFF) ;---------------------------------------------------------------------------- ldr r1,memmap_tbl+12 ldrb r0,[r1,addy] orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- rom_R80 ;rom read ($8000-$9FFF) ;---------------------------------------------------------------------------- ldr r1,memmap_tbl+16 ldrb r0,[r1,addy] orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- rom_RA0 ;rom read ($A000-$BFFF) ;---------------------------------------------------------------------------- ldr r1,memmap_tbl+20 ldrb r0,[r1,addy] orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- rom_RC0 ;rom read ($C000-$DFFF) ;---------------------------------------------------------------------------- ldr r1,memmap_tbl+24 ldrb r0,[r1,addy] orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- rom_RE0 ;rom read ($E000-$FFFF) ;---------------------------------------------------------------------------- ldr r1,memmap_tbl+28 ldrb r0,[r1,addy] orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr nop ;---------------------------------------------------------------------------- ;IO AREA io_code, CODE, READONLY ;-- ;---------------------------------------------------------------------------- ;---------------------------------------------------------------------------- IO_R ;I/O read ;---------------------------------------------------------------------------- mov r2,#0x4018 ;$4018-$6000 cmp r12,r2 bhi Read_Low ;HI 无符号数大于 C==1 && Z==0 sub r1,r12,#0x4000 ;addy=r12 subs r1,r1,#0x15 bmi empty_R ;读地址不正确 MI 负数(MInus) N==1 cmp r1,#3 ; ldrmi pc,[pc,r2,lsl#2] ldr r2,=io_read_tbl ;//改过，加3行 add r2,r2,r1,lsl#2 ;<<2 ldrmi pc,[r2] b empty_R ;读地址不正确 ; nop io_read_tbl DCD apu_4015R;void;_4015r ;4015 (sound) DCD joy0_R ;4016: controller 1 DCD joy1_R ;4017: controller 2 ;---------------------------------------------------------------------------- IO_W ;I/O write ;---------------------------------------------------------------------------- mov r2,#0x4018 ;$4018-$6000 cmp r12,r2 bhi Write_Low ;HI 无符号数大于 C==1 && Z==0 sub r1,r12,#0x4000 ;addy=r12 cmp r1,#0x18 ; ldrmi pc,[pc,r2,lsl#2] ldr r2,=io_write_tbl ;//改过，加3行 add r2,r2,r1,lsl#2 ;<<2 ldrmi pc,[r2] ;//直接操作pc太他妈危险了 b empty_R ;读地址不正确 nop io_write_tbl DCD apu_w;void;_4000w DCD apu_w;_4001w DCD apu_w;_4002w DCD apu_w;_4003w DCD apu_w;_4004w DCD apu_w;_4005w DCD apu_w;_4006w DCD apu_w;_4007w DCD apu_w;_4008w DCD apu_w;void; DCD apu_w;_400aw DCD apu_w;void;_400bw DCD apu_w;void;_400cw DCD apu_w;void DCD apu_w;void;_400ew DCD apu_w;void;_400fw DCD apu_w;void;_4010w DCD apu_w;void;_4011w DCD apu_w;void;_4012w DCD apu_w;void;_4013w DCD dma_W ;$4014: Sprite DMA transfer DCD apu_4015w;void;_4015w ; 声音通道切换 DCD joy0_W ;$4016: Joypad 0 write;joypad_write_ptr DCD void;joy1_W;$4017: ? ;------------------------------------------------------------------------------- IMPORT asm_Mapper_ReadLow Read_Low PROC;$5000-$6000 mapper->MemoryReadLow(addr); ;------------------------------------------------------------------------------ stmfd sp!,{r3,lr} ;LR 寄存器放栈 mov r0,r12 bl asm_Mapper_ReadLow ldmfd sp!,{r3,lr} orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ENDP ;------------------------------------------------------------------------------- IMPORT asm_Mapper_WriteLow Write_Low PROC;$5000-$6000 mapper->MemoryWriteLow( data, addr); ;------------------------------------------------------------------------------ stmfd sp!,{r3,lr} ;LR 寄存器放栈 mov r1,r12 bl asm_Mapper_WriteLow ldmfd sp!,{r3,lr} orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ENDP ;----------------------------------------------------------------------------- IMPORT Apu_Write ;apu.c IMPORT Apu_Write4015 ;apu.c ;----------------------------------------------------------------------------------- apu_w ; 0x4000--0x4013 ;--------------------------------------------------------------------------------- stmfd sp!,{r3,lr} ;LR 寄存器放栈 bl Apu_Write ldmfd sp!,{r3,lr} orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;----------------------------------------------------------------------------------- apu_4015w ;------------------------------------------------------------------------- stmfd sp!,{r3,lr} ;LR 寄存器放栈 bl Apu_Write4015 ldmfd sp!,{r3,lr} orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- IMPORT Apu_Read4015 ;apu.c apu_4015R ;4015 ;---------------------------------------------------------------------------------- stmfd sp!,{r3,lr} ;LR 寄存器放栈 add r0,r1,#0x15 bl Apu_Read4015 ldmfd sp!,{r3,lr} orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- dma_W ;(4014) sprite DMA transfer 精灵DMA传输 DMA访问精灵RAM： ;通过写一个值xx到这个端口，引起CPU内存地址为$xx00－$xxFF的区域传送到精灵内存 ;---------------------------------------------------------------------------- sub cycles,cycles,#512*256 stmfd sp!,{r3,lr} and r1,r0,#0xe0 adr r2,memmap_tbl lsr r1,r1,#3 ldr r2,[r2,r1] and r0,r0,#0xff add r2,r2,r0,lsl#8 ;addy r2=DMA source 源 ldr r1,=spr_ram ;r1 DMA的 目的地 ppu.c ldr r1,[r1] ;spr_ram用了指针 mov r0,#64 ;256/4/8 copy_ subs r0,r0,#1 ;-1 ldr r3,[r2,r0,lsl#2] str r3,[r1,r0,lsl#2] ;<<2 *4 bne copy_ ldmfd sp!,{r3,lr} orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- IMPORT PADdata IMPORT PADdata1 joy0_W ;4016 手柄1键值 [7:0]右7 左6 下5 上4 Start3 Select2 B1 A0 ) ;---------------------------------------------------------------------------- tst r0,#1 ;0＝写，1＝读 orr lr,#0x01 ;lr最低位置1防止进入arm状态 bxne lr ;NE 不等（NotEqual） ldr r1,=PADdata; //手柄1键值 ldr r1,[r1] str r1,joy0data ldr r1,=PADdata1; //手柄1键值 ldr r1,[r1] str r1,joy1data bx lr ;----------------------------------------------------------------------------- joy1_W ;4017 手柄1键值 [7:0]右7 左6 下5 上4 Start3 Select2 B1 A0 ) ;---------------------------------------------------------------------------- ;tst r0,#1 ; 0＝??，1＝读 ;orr lr,#0x01 ;lr最低位置1防止进入arm状态 ;bxne lr ;NE 不等（NotEqual） bx lr ;---------------------------------------------------------------------------- joy0_R ;4016 ;---------------------------------------------------------------------------- ldr r0,joy0data ;串行数据 当前读取位;joy0data是键值 mov r1,r0,lsr#1 ;>>1 str r1,joy0data and r0,r0,#1 ;&1 orr r0,r0,#0x40 ;|0x40 orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;---------------------------------------------------------------------------- joy1_R ;4017 ;---------------------------------------------------------------------------- ldr r0,joy1data ;串行数据 当前读取位;joy0data是键值 mov r1,r0,lsr#1 ;>>1 str r1,joy1data and r0,r0,#1 ;&1 orr r0,r0,#0x40 ;|0x80？ 0xf8? orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;-------------------------------------------------------------- K6502_Read PROC;apu Rendering DPCM channel #5 r0=APU->ApuC5Address不确定正确* ;--------------------------------------------------------------- EXPORT K6502_Read ;switch ( wAddr & 0xe000 ) apu.c stmfd sp!,{lr} mov r1,r0,lsr#13 ;>>13= & 0xe000 ldr r2,=CPU_RAM;;//存储器映象 ram+rom ldr r1,[r2,r1,lsl#2] ;lookup rom ptr..查找ptr bic r0,r0,#0xe000 ;and r0,#0x1fff &0x1fff ldrb r0,[r1,r0] ldmfd sp!,{lr} bx lr ENDP nop ;------------------------------------------------------------------------ AREA CPU_GPU, CODE, READONLY IMPORT PPU_WriteToPort ;PPU.c IMPORT PPU_ReadFromPort ;PPU.c ;------------------------------------------------------------------------------------ PPU_W stmfd sp!,{r3,lr} ;LR 寄存器放栈 mov r1,r12 bl PPU_WriteToPort ldmfd sp!,{r3,lr} orr lr,#0x01 ;lr最低位置1防止进入arm状态 bx lr ;-------------------------------------------------------------------------------------- PPU_R stmfd sp!,{r3,lr} ;LR 寄存器放栈 会改变R4 mov r0,r12 bl PPU_ReadFromPort ldmfd sp!,{r3,lr} orr lr,#0x01 bx lr nop ;----------------------------------------------------------------------------------------- AREA cpu_code, DATA, READONLY ;----------------------------------------------------------------------------------------- op_table ;DCD 用于分配一段字内存单元 op_table内存块起始地址标号 DCD _00,_01,_xx,_03,_xx,_05,_06,_07,_08,_09,_0A,_xx,_xx,_0D,_0E,_xx DCD _10,_11,_xx,_xx,_14,_15,_16,_xx,_18,_19,_xx,_xx,_xx,_1D,_1E,_xx DCD _20,_21,_xx,_xx,_24,_25,_26,_xx,_28,_29,_2A,_xx,_2C,_2D,_2E,_xx DCD _30,_31,_xx,_xx,_xx,_35,_36,_xx,_38,_39,_xx,_xx,_xx,_3D,_3E,_xx DCD _40,_41,_xx,_xx,_xx,_45,_46,_xx,_48,_49,_4A,_xx,_4C,_4D,_4E,_xx DCD _50,_51,_xx,_xx,_xx,_55,_56,_xx,_58,_59,_xx,_xx,_xx,_5D,_5E,_xx DCD _60,_61,_xx,_xx,_xx,_65,_66,_67,_68,_69,_6A,_xx,_6C,_6D,_6E,_xx DCD _70,_71,_xx,_xx,_xx,_75,_76,_xx,_78,_79,_xx,_xx,_xx,_7D,_7E,_xx DCD _xx,_81,_xx,_xx,_84,_85,_86,_xx,_88,_xx,_8A,_xx,_8C,_8D,_8E,_xx DCD _90,_91,_xx,_xx,_94,_95,_96,_xx,_98,_99,_9A,_xx,_xx,_9D,_xx,_xx DCD _A0,_A1,_A2,_xx,_A4,_A5,_A6,_xx,_A8,_A9,_AA,_xx,_AC,_AD,_AE,_xx DCD _B0,_B1,_xx,_xx,_B4,_B5,_B6,_xx,_B8,_B9,_BA,_xx,_BC,_BD,_BE,_xx DCD _C0,_C1,_xx,_xx,_C4,_C5,_C6,_xx,_C8,_C9,_CA,_xx,_CC,_CD,_CE,_xx DCD _D0,_D1,_xx,_xx,_xx,_D5,_D6,_xx,_D8,_D9,_xx,_xx,_xx,_DD,_DE,_xx DCD _E0,_E1,_xx,_xx,_E4,_E5,_E6,_xx,_E8,_E9,_EA,_xx,_EC,_ED,_EE,_xx DCD _F0,_F1,_xx,_xx,_xx,_F5,_F6,_xx,_F8,_F9,_xx,_FB,_xx,_FD,_FE,_FF ;--------------------------------------------------------------------------------- AREA wram_globals0, DATA, READWRITE ;--------------------------------------------------------------------------------- cpu_data DCD 0 ;opz # 4 //代码表地址 ;readmem_tbl DCD ram_R ;$0000 DCD PPU_R ;$2000 DCD IO_R ;$4000 DCD sram_R ;$6000 DCD rom_R80 ;$8000 DCD rom_RA0 ;$A000 DCD rom_RC0 ;$C000 DCD rom_RE0 ;$E000 ;writemem_tbl DCD ram_W ;$0000 DCD PPU_W ;$2000 r0传参数 DCD IO_W ;$4000 DCD sram_W ;$6000 DCD void ;$8000 DCD void ;$A000 DCD void ;$C000 DCD void ;$E000 CPU_RAM ;memmap_tbl 存储器映象 DCD NES_RAM ;$0000 0000-7fff keep $400 byte aligned for 6502 stack shit DCD NES_RAM ;$2000 should 保持1024字节对齐 DCD NES_RAM ;$4000 never DCD NES_SRAM; NES_RAM-0x5800 ;$6000 change改变 rommap % 4*4 ;$8000-FFFF memmap_tbl+16 cpustate ;group these together for save/loadstate % 7*4 ;cpuregs (nz,c,a,x,y,cycles,pc) DCD 0 ;m6502_s: DCD 0 ;lastbank: 最后MEMMAP添加到PC （用于计算当前的PC ） DCD 0 ;nexttimeout: jump here when cycles runs out 跳到下一个时钟周期运行 DCD 0 ;rombase # 4 ;//ROM开始地址 DCD 0 ;romnumber # 4 ;// DCD 0 ;rommask # 4 ;//ROM掩膜 rommask=romsize-1 DCD 0 ;joy0data # 4 ;//手柄1串行数据 DCD 0 ;joy1data # 4 ;//手柄2串行数据 clocks DCD 0 ;clocksh # 4 ;//执行的时钟数 apu用 cpunmi DCD 0 ;cpunmif # 4 ;cpu中断标志 cpuirq DCD 0 ;cpuirqf # 4 ;cpu中断标志 ; DCW 0 DCW定义16位变量 ;---------------------------------------------------------------------------- ; ALIGN ;通过用零或空指令NOP填充，来使当前位置与一个指定的边界对齐 END ;align 4