Shamusworld >> Repos - thunder/blob - src/v63701.h

   1 //
   2 // Virtual 63701 Header file
   3 //
   4 // by James Hammons
   5 // (C) 2014 Underground Software
   6 //
   7 #ifndef __V63701_H__
   8 #define __V63701_H__
   9
  10 #include <stdint.h>
  11
  12 // Useful defines
  13
  14 #define FLAG_H          0x20            // Half carry
  15 #define FLAG_I          0x10            // IRQ
  16 #define FLAG_N          0x08            // Negative
  17 #define FLAG_Z          0x04            // Zero
  18 #define FLAG_V          0x02            // oVerflow
  19 #define FLAG_C          0x01            // Carry
  20
  21 #define V63701_LINE_RESET               0x0001  // v63701 RESET line
  22 #define V63701_LINE_IRQ                 0x0002  // v63701 IRQ line
  23 #define V63701_LINE_NMI                 0x0004  // v63701 NMI line
  24 #define V63701_STATE_WAI                0x0008  // v63701 wait for IRQ line
  25 #define V63701_TIMER_OVERFLOW   0x0010
  26 #define V63701_OUTPUT_COMPARE   0x0020
  27 #define V63701_INPUT_CAPTURE    0x0040
  28 #define V63701_TRAP                             0x0080  // Illegal instruction executed flag
  29 //#define V6809_START_DEBUG_LOG         0x8000  // Debug log go (temporary!)
  30
  31 // Useful structs
  32
  33 union Byte
  34 {
  35         struct
  36         {
  37                 uint8_t b0: 1; uint8_t b1: 1; uint8_t b2: 1; uint8_t b3: 1;
  38                 uint8_t b4: 1; uint8_t b5: 1; uint8_t b6: 1; uint8_t b7: 1;
  39         } bit;
  40         uint8_t byte;
  41 };
  42
  43 union Word
  44 {
  45         struct
  46         {
  47                 uint8_t lo: 8;
  48                 uint8_t hi: 8;
  49         } byte;
  50         uint16_t word;
  51 };
  52
  53 union Flags
  54 {
  55         struct
  56         {
  57                 uint8_t c: 1;
  58                 uint8_t v: 1;
  59                 uint8_t z: 1;
  60                 uint8_t n: 1;
  61                 uint8_t i: 1;
  62                 uint8_t h: 1;
  63         } flag;
  64         uint8_t byte;
  65 };
  66
  67 union TCSR
  68 {
  69         struct
  70         {
  71                 uint8_t olvl: 1;
  72                 uint8_t iedg: 1;
  73                 uint8_t etoi: 1;        // Enable Timer Over
  74                 uint8_t eoci: 1;        // Enable Output Compare
  75                 uint8_t eici: 1;        // Enable Input Capture
  76                 uint8_t tof: 1;         // Timer Over
  77                 uint8_t ocf: 1;         // Output Compare
  78                 uint8_t icf: 1;         // Input Capture
  79         } bit;
  80         uint8_t byte;
  81 };
  82
  83 union WordReg
  84 {
  85         struct
  86         {
  87                 uint8_t b: 8;
  88                 uint8_t a: 8;
  89         } acc;
  90         uint16_t word;
  91 };
  92
  93 struct V63701REGS
  94 {
  95         uint16_t pc;                                    // 63701 PC register
  96         uint16_t x;                                             // 63701 X index register
  97         uint16_t s;                                             // 63701 System stack pointer
  98         uint8_t cc;                                             // 63701 Condition Code register
  99 //      uint8_t a;                                              // 63701 A register
 100 //      uint8_t b;                                              // 63701 B register
 101         WordReg d;                                              // 63701 A & B registers (A is hi, B is lo)
 102         TCSR tcsr;                                              // 63701 Timer control/Status register
 103         Word counter;                                   // 63701 Counter register
 104         Word outputCompare;                             // 63701 Output Compare register
 105         uint8_t ddr1;
 106         uint8_t ddr2;
 107         uint8_t port1data;
 108         uint8_t port2data;
 109         uint8_t ramCtrl;
 110         uint8_t cWriteLatch;                    // Counter write latch
 111         uint8_t cReadLatch;                             // Counter read latch
 112         bool tcsrWasRead;                               // TCSR was read flag
 113         uint64_t clock;                                 // 63701 clock
 114         uint8_t (* RdMem)(uint16_t);    // Address of uint8 read routine
 115         void (* WrMem)(uint16_t, uint8_t);      // Address of uint8 write routine
 116         uint32_t cpuFlags;                              // v63701 IRQ/RESET flags
 117         uint32_t clockOverrun;                  // Amount of overflow between runs
 118 };
 119
 120 // Function prototypes
 121
 122 void Execute63701(V63701REGS *, uint32_t);      // Function to execute 63701 instructions
 123 uint64_t GetCurrentV63701Clock(void);           // Get the clock of the currently executing CPU
 124
 125 // It's the responsibility of the user to call these from their R/W handlers.
 126 // These are usually memory mapped at $00-$1F.
 127 uint8_t InternalRegisterRead(uint16_t);
 128 void InternalRegisterWrite(uint16_t, uint8_t);
 129
 130 // These functions must be implemented by the user...
 131 extern uint8_t V63701ReadPort1(void);
 132 extern uint8_t V63701ReadPort2(void);
 133 extern void V63701WritePort1(uint8_t);
 134 extern void V63701WritePort2(uint8_t);
 135
 136 #endif  // __V63701_H__