Annotation of hatari/src/includes/m68000.h, revision 1.1.1.15

1.1       root        1: /*
1.1.1.5   root        2:   Hatari - m68000.h
                      3: 
                      4:   This file is distributed under the GNU Public License, version 2 or at
                      5:   your option any later version. Read the file gpl.txt for details.
1.1       root        6: */
                      7: 
1.1.1.10  root        8: /* 2007/11/10  [NP]    Add pairing for lsr / dbcc (and all variants    */
                      9: /*                     working on register, not on memory).            */
                     10: /* 2008/01/07  [NP]    Use PairingArray to store all valid pairing     */
                     11: /*                     combinations (in m68000.c)                      */
1.1.1.14  root       12: /* 2010/04/05  [NP]    Rework the pairing code to take BusCyclePenalty */
                     13: /*                     into account when using d8(an,ix).              */
                     14: /* 2010/05/07  [NP]    Add BusCyclePenalty to LastInstrCycles to detect*/
                     15: /*                     a possible pairing between add.l (a5,d1.w),d0   */
                     16: /*                     and move.b 7(a5,d1.w),d5.                       */
                     17: 
1.1.1.10  root       18: 
1.1.1.5   root       19: #ifndef HATARI_M68000_H
                     20: #define HATARI_M68000_H
                     21: 
1.1.1.9   root       22: #include "cycles.h"     /* for nCyclesMainCounter */
1.1.1.6   root       23: #include "sysdeps.h"
                     24: #include "memory.h"
1.1.1.9   root       25: #include "newcpu.h"     /* for regs */
1.1.1.14  root       26: #include "cycInt.h"
1.1.1.11  root       27: #include "log.h"
                     28: 
                     29: 
                     30: /* 68000 Register defines */
                     31: enum {
                     32:   REG_D0,    /* D0.. */
                     33:   REG_D1,
                     34:   REG_D2,
                     35:   REG_D3,
                     36:   REG_D4,
                     37:   REG_D5,
                     38:   REG_D6,
                     39:   REG_D7,    /* ..D7 */
                     40:   REG_A0,    /* A0.. */
                     41:   REG_A1,
                     42:   REG_A2,
                     43:   REG_A3,
                     44:   REG_A4,
                     45:   REG_A5,
                     46:   REG_A6,
                     47:   REG_A7,    /* ..A7 (also SP) */
                     48: };
                     49: 
                     50: /* 68000 Condition code's */
                     51: #define SR_AUX              0x0010
                     52: #define SR_NEG              0x0008
                     53: #define SR_ZERO             0x0004
                     54: #define SR_OVERFLOW         0x0002
                     55: #define SR_CARRY            0x0001
                     56: 
                     57: #define SR_CLEAR_AUX        0xffef
                     58: #define SR_CLEAR_NEG        0xfff7
                     59: #define SR_CLEAR_ZERO       0xfffb
                     60: #define SR_CLEAR_OVERFLOW   0xfffd
                     61: #define SR_CLEAR_CARRY      0xfffe
                     62: 
                     63: #define SR_CCODE_MASK       (SR_AUX|SR_NEG|SR_ZERO|SR_OVERFLOW|SR_CARRY)
                     64: #define SR_MASK             0xFFE0
                     65: 
                     66: #define SR_TRACEMODE        0x8000
                     67: #define SR_SUPERMODE        0x2000
                     68: #define SR_IPL              0x0700
                     69: 
                     70: #define SR_CLEAR_IPL        0xf8ff
                     71: #define SR_CLEAR_TRACEMODE  0x7fff
                     72: #define SR_CLEAR_SUPERMODE  0xdfff
                     73: 
                     74: /* Exception vectors */
                     75: #define  EXCEPTION_BUSERROR   0x00000008
                     76: #define  EXCEPTION_ADDRERROR  0x0000000c
                     77: #define  EXCEPTION_ILLEGALINS 0x00000010
                     78: #define  EXCEPTION_DIVZERO    0x00000014
                     79: #define  EXCEPTION_CHK        0x00000018
                     80: #define  EXCEPTION_TRAPV      0x0000001c
                     81: #define  EXCEPTION_TRACE      0x00000024
                     82: #define  EXCEPTION_LINE_A     0x00000028
                     83: #define  EXCEPTION_LINE_F     0x0000002c
                     84: #define  EXCEPTION_HBLANK     0x00000068
                     85: #define  EXCEPTION_VBLANK     0x00000070
                     86: #define  EXCEPTION_TRAP0      0x00000080
                     87: #define  EXCEPTION_TRAP1      0x00000084
                     88: #define  EXCEPTION_TRAP2      0x00000088
                     89: #define  EXCEPTION_TRAP13     0x000000B4
                     90: #define  EXCEPTION_TRAP14     0x000000B8
                     91: 
                     92: 
                     93: /* Size of 68000 instructions */
                     94: #define MAX_68000_INSTRUCTION_SIZE  10  /* Longest 68000 instruction is 10 bytes(6+4) */
                     95: #define MIN_68000_INSTRUCTION_SIZE  2   /* Smallest 68000 instruction is 2 bytes(ie NOP) */
                     96: 
                     97: /* Illegal Opcode used to help emulation. eg. free entries are 8 to 15 inc' */
                     98: #define  GEMDOS_OPCODE        8  /* Free op-code to intercept GemDOS trap */
                     99: #define  SYSINIT_OPCODE      10  /* Free op-code to initialize system (connected drives etc.) */
                    100: #define  VDI_OPCODE          12  /* Free op-code to call VDI handlers AFTER Trap#2 */
                    101: 
1.1.1.10  root      102: 
                    103: 
                    104: /* Ugly hacks to adapt the main code to the different CPU cores: */
                    105: 
                    106: #define Regs regs.regs
                    107: 
                    108: 
                    109: # define M68000_GetPC()     m68k_getpc()
                    110: # define M68000_SetPC(val)  m68k_setpc(val)
                    111: 
                    112: static inline Uint16 M68000_GetSR(void)
                    113: {
                    114:        MakeSR();
                    115:        return regs.sr;
                    116: }
                    117: static inline void M68000_SetSR(Uint16 v)
                    118: {
                    119:        regs.sr = v;
                    120:        MakeFromSR();
                    121: }
                    122: 
                    123: # define M68000_SetSpecial(flags)   set_special(flags)
                    124: # define M68000_UnsetSpecial(flags) unset_special(flags)
                    125: 
                    126: 
1.1.1.9   root      127: /* bus error mode */
                    128: #define BUS_ERROR_WRITE 0
                    129: #define BUS_ERROR_READ 1
                    130: 
1.1.1.10  root      131: 
1.1.1.15! root      132: /* bus access mode */
1.1.1.12  root      133: #define        BUS_MODE_CPU            0                       /* bus is owned by the cpu */
                    134: #define        BUS_MODE_BLITTER        1                       /* bus is owned by the blitter */
                    135: 
                    136: 
1.1.1.7   root      137: extern Uint32 BusErrorAddress;
1.1.1.5   root      138: extern Uint32 BusErrorPC;
1.1.1.11  root      139: extern bool bBusErrorReadWrite;
1.1.1.7   root      140: extern int nCpuFreqShift;
1.1.1.9   root      141: extern int nWaitStateCycles;
1.1.1.12  root      142: extern int BusMode;
1.1.1.6   root      143: 
1.1.1.10  root      144: extern int     LastOpcodeFamily;
                    145: extern int     LastInstrCycles;
                    146: extern int     Pairing;
                    147: extern char    PairingArray[ MAX_OPCODE_FAMILY ][ MAX_OPCODE_FAMILY ];
                    148: extern const char *OpcodeName[];
                    149: 
1.1.1.6   root      150: 
                    151: /*-----------------------------------------------------------------------*/
1.1.1.10  root      152: /**
                    153:  * Add CPU cycles.
                    154:  * NOTE: All times are rounded up to nearest 4 cycles.
                    155:  */
1.1.1.6   root      156: static inline void M68000_AddCycles(int cycles)
                    157: {
1.1.1.10  root      158:        cycles = (cycles + 3) & ~3;
                    159:        cycles = cycles >> nCpuFreqShift;
                    160: 
                    161:        PendingInterruptCount -= INT_CONVERT_TO_INTERNAL(cycles, INT_CPU_CYCLE);
1.1.1.9   root      162:        nCyclesMainCounter += cycles;
1.1.1.6   root      163: }
1.1.1.5   root      164: 
1.1.1.10  root      165: 
                    166: /*-----------------------------------------------------------------------*/
                    167: /**
1.1.1.14  root      168:  * Add CPU cycles, take cycles pairing into account. Pairing will make
                    169:  * some specific instructions take 4 cycles less when run one after the other.
                    170:  * Pairing happens when the 2 instructions are "aligned" on different bus accesses.
                    171:  * Candidates are :
                    172:  *  - 2 instructions taking 4n+2 cycles
                    173:  *  - 1 instruction taking 4n+2 cycles, followed by 1 instruction using d8(an,ix)
                    174:  *
                    175:  * Not all the candidate instructions can pair, only the opcodes listed in PairingArray.
                    176:  * On ST, when using d8(an,ix), we get an extra 2 cycle penalty for misaligned bus access.
                    177:  * The only instruction that can generate BusCyclePenalty=4 is move d8(an,ix),d8(an,ix)
                    178:  * and although it takes 4n cycles (24 for .b/.w or 32 for .l) it can pair with
                    179:  * a previous 4n+2 instruction (but it will still have 1 misaligned bus access in the end).
                    180:  *
                    181:  * Verified pairing on an STF :
                    182:  *  - lsl.w #4,d1 + move.w 0(a4,d2.w),d1               motorola=14+14=28  stf=28
                    183:  *  - lsl.w #4,d1 + move.w 0(a4,d2.w),(a4)             motorola=14+18=32  stf=32
                    184:  *  - lsl.w #4,d1 + move.w 0(a4,d2.w),0(a4,d2.w)       motorola=14+24=38  stf=40
                    185:  *  - add.l (a5,d1.w),d0 + move.b 7(a5,d1.w),d5)       motorola=20+14=34  stf=36
                    186:  *
                    187:  * d8(an,ix) timings without pairing (2 cycles penalty) :
                    188:  *  - add.l   0(a4,d2.w),a1                            motorola=20  stf=24
                    189:  *  - move.w  0(a4,d2.w),d1                            motorola=14  stf=16
                    190:  *  - move.w  0(a4,d2.w),(a4)                          motorola=18  stf=20
                    191:  *  - move.w  0(a4,d2.w),0(a4,d2.w)                    motorola=24  stf=28
                    192:  *
1.1.1.10  root      193:  * NOTE: All times are rounded up to nearest 4 cycles.
                    194:  */
                    195: static inline void M68000_AddCyclesWithPairing(int cycles)
                    196: {
                    197:        Pairing = 0;
                    198:        /* Check if number of cycles for current instr and for */
                    199:        /* the previous one is of the form 4+2n */
                    200:        /* If so, a pairing could be possible depending on the opcode */
1.1.1.14  root      201:        /* A pairing is also possible if current instr is 4n but with BusCyclePenalty > 0 */
1.1.1.10  root      202:        if ( ( PairingArray[ LastOpcodeFamily ][ OpcodeFamily ] == 1 )
1.1.1.14  root      203:            && ( ( LastInstrCycles & 3 ) == 2 )
                    204:            && ( ( ( cycles & 3 ) == 2 ) || ( BusCyclePenalty > 0 ) ) )
1.1.1.10  root      205:        {
                    206:                Pairing = 1;
1.1.1.13  root      207:                LOG_TRACE(TRACE_CPU_PAIRING,
                    208:                          "cpu pairing detected pc=%x family %s/%s cycles %d/%d\n",
                    209:                          m68k_getpc(), OpcodeName[LastOpcodeFamily],
                    210:                          OpcodeName[OpcodeFamily], LastInstrCycles, cycles);
1.1.1.10  root      211:        }
                    212: 
1.1.1.11  root      213:        /* [NP] This part is only needed to track possible pairing instructions, */
                    214:        /* we can keep it disabled most of the time */
                    215: #if 0
                    216:        if ( (LastOpcodeFamily!=OpcodeFamily) && ( Pairing == 0 )
                    217:                && ( ( cycles & 3 ) == 2 ) && ( ( LastInstrCycles & 3 ) == 2 ) )
                    218:        {
1.1.1.13  root      219:                LOG_TRACE(TRACE_CPU_PAIRING,
                    220:                          "cpu could pair pc=%x family %s/%s cycles %d/%d\n",
                    221:                          m68k_getpc(), OpcodeName[LastOpcodeFamily],
                    222:                          OpcodeName[OpcodeFamily], LastInstrCycles, cycles);
1.1.1.11  root      223:        }
                    224: #endif
                    225: 
1.1.1.10  root      226:        /* Store current instr (not rounded) to check next time */
1.1.1.14  root      227:        LastInstrCycles = cycles + BusCyclePenalty;
1.1.1.10  root      228:        LastOpcodeFamily = OpcodeFamily;
                    229: 
                    230:        /* If pairing is true, we need to substract 2 cycles for the    */
                    231:        /* previous instr which was rounded to 4 cycles while it wasn't */
                    232:        /* needed (and we don't round the current one)                  */
                    233:        /* -> both instr will take 4 cycles less on the ST than if ran  */
                    234:        /* separately.                                                  */
                    235:        if (Pairing == 1)
1.1.1.14  root      236:        {
                    237:                if ( ( cycles & 3 ) == 2 )              /* pairing between 4n+2 and 4n+2 instructions */
                    238:                        cycles -= 2;                    /* if we have a pairing, we should not count the misaligned bus access */
                    239: 
                    240:                else                                    /* this is the case of move d8(an,ix),d8(an,ix) where BusCyclePenalty=4 */
                    241:                        /*do nothing */;                /* we gain 2 cycles for the pairing with 1st d8(an,ix) */
                    242:                                                        /* and we have 1 remaining misaligned access for the 2nd d8(an,ix). So in the end, we keep */
                    243:                                                        /* cycles unmodified as 4n cycles (eg lsl.w #4,d1 + move.w 0(a4,d2.w),0(a4,d2.w) takes 40 cycles) */
                    244:        }
1.1.1.10  root      245:        else
1.1.1.14  root      246:        {
                    247:                cycles += BusCyclePenalty;              /* >0 if d8(an,ix) was used */
                    248:                cycles = (cycles + 3) & ~3;             /* no pairing, round current instr to 4 cycles */
                    249:        }
1.1.1.10  root      250: 
                    251:        cycles = cycles >> nCpuFreqShift;
                    252: 
                    253:        PendingInterruptCount -= INT_CONVERT_TO_INTERNAL ( cycles , INT_CPU_CYCLE );
                    254: 
                    255:        nCyclesMainCounter += cycles;
1.1.1.14  root      256:        BusCyclePenalty = 0;
1.1.1.10  root      257: }
                    258: 
                    259: 
1.1.1.14  root      260: extern void M68000_Init(void);
1.1.1.11  root      261: extern void M68000_Reset(bool bCold);
1.1.1.10  root      262: extern void M68000_Start(void);
1.1.1.15! root      263: extern void M68000_CheckCpuSettings(void);
1.1.1.11  root      264: extern void M68000_MemorySnapShot_Capture(bool bSave);
                    265: extern void M68000_BusError(Uint32 addr, bool bReadWrite);
                    266: extern void M68000_Exception(Uint32 ExceptionVector , int ExceptionSource);
1.1.1.9   root      267: extern void M68000_WaitState(int nCycles);
1.1.1.5   root      268: 
                    269: #endif

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