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
   8 #ifndef __V63701_H__
   9 #define __V63701_H__
  10
  11 #include <stdint.h>
  12
  13 // Useful defines
  14
  15 #define FLAG_H          0x20            // Half carry
  16 #define FLAG_I          0x10            // IRQ
  17 #define FLAG_N          0x08            // Negative
  18 #define FLAG_Z          0x04            // Zero
  19 #define FLAG_V          0x02            // oVerflow
  20 #define FLAG_C          0x01            // Carry
  21
  22 #define V63701_ASSERT_LINE_RESET        0x0001  // v63701 RESET line
  23 #define V63701_ASSERT_LINE_IRQ          0x0002  // v63701 IRQ line
  24 #define V63701_ASSERT_LINE_NMI          0x0004  // v63701 NMI line
  25 #define V63701_STATE_WAI                        0x0008  // v63701 wait for IRQ line
  26 #define V63701_ASSERT_TIMER_OVERFLOW    0x0010
  27 #define V63701_ASSERT_OUTPUT_COMPARE    0x0020
  28 #define V63701_ASSERT_INPUT_CAPTURE     0x0040
  29 #define V63701_ASSERT_TRAP                      0x0080  // Illegal instruction executed flag
  30 //#define V6809_START_DEBUG_LOG         0x8000  // Debug log go (temporary!)
  31
  32 // Useful structs
  33
  34 union Byte
  35 {
  36         struct
  37         {
  38                 uint8_t b0: 1; uint8_t b1: 1; uint8_t b2: 1; uint8_t b3: 1;
  39                 uint8_t b4: 1; uint8_t b5: 1; uint8_t b6: 1; uint8_t b7: 1;
  40         } bit;
  41         uint8_t byte;
  42 };
  43
  44 union Word
  45 {
  46         struct
  47         {
  48                 uint8_t lo: 8;
  49                 uint8_t hi: 8;
  50         } byte;
  51         uint16_t word;
  52 };
  53
  54 union Flags
  55 {
  56         struct
  57         {
  58                 uint8_t c: 1;
  59                 uint8_t v: 1;
  60                 uint8_t z: 1;
  61                 uint8_t n: 1;
  62                 uint8_t i: 1;
  63                 uint8_t h: 1;
  64         } flag;
  65         uint8_t byte;
  66 };
  67
  68 union TCSR
  69 {
  70         struct
  71         {
  72                 uint8_t olvl: 1;
  73                 uint8_t iedg: 1;
  74                 uint8_t etoi: 1;        // Enable Timer Over
  75                 uint8_t eoci: 1;        // Enable Output Compare
  76                 uint8_t eici: 1;        // Enable Input Capture
  77                 uint8_t tof: 1;         // Timer Over
  78                 uint8_t ocf: 1;         // Output Compare
  79                 uint8_t icf: 1;         // Input Capture
  80         } bit;
  81         uint8_t byte;
  82 };
  83
  84 union WordReg
  85 {
  86         struct
  87         {
  88                 uint8_t b: 8;
  89                 uint8_t a: 8;
  90         } acc;
  91         uint16_t word;
  92 };
  93
  94 struct V63701REGS
  95 {
  96         uint16_t pc;                                    // 63701 PC register
  97         uint16_t x;                                             // 63701 X index register
  98         uint16_t s;                                             // 63701 System stack pointer
  99         uint8_t cc;                                             // 63701 Condition Code register
 100 //      uint8_t a;                                              // 63701 A register
 101 //      uint8_t b;                                              // 63701 B register
 102         WordReg d;                                              // 63701 A & B registers (A is hi, B is lo)
 103         TCSR tcsr;                                              // 63701 Timer control/Status register
 104         Word counter;                                   // 63701 Counter register
 105         Word outputCompare;                             // 63701 Output Compare register
 106         uint8_t ddr1;
 107         uint8_t ddr2;
 108         uint8_t port1;
 109         uint8_t port2;
 110         uint8_t ramCtrl;
 111         uint8_t cWriteLatch;                    // Counter write latch
 112         uint8_t cReadLatch;                             // Counter read latch
 113         bool tcsrWasRead;                               // TCSR was read flag
 114         uint64_t clock;                                 // 63701 clock
 115         uint8_t (* RdMem)(uint16_t);    // Address of uint8 read routine
 116         void (* WrMem)(uint16_t, uint8_t);      // Address of uint8 write routine
 117         uint32_t cpuFlags;                              // v63701 IRQ/RESET flags
 118         uint32_t clockOverrun;                  // Amount of overflow between runs
 119 };
 120
 121 // Function prototypes
 122
 123 void Execute63701(V63701REGS *, uint32_t);      // Function to execute 63701 instructions
 124 uint64_t GetCurrentV63701Clock(void);           // Get the clock of the currently executing CPU
 125
 126 // It's the responsibility of the user to call these from their R/W handlers.
 127 // These are usually memory mapped at $00-$1F.
 128 uint8_t InternalRegisterRead(uint16_t);
 129 void InternalRegisterWrite(uint16_t, uint8_t);
 130
 131 #endif  // __V63701_H__
 132