Shamusworld >> Repos - thunder/blob - src/v6809.h

   1 //
   2 // Virtual 6809 Header file
   3 //
   4 // by James Hammons
   5 //
   6 // (C) 1997, 2014 Underground Software
   7 //
   8
   9 #ifndef __V6809_H__
  10 #define __V6809_H__
  11
  12 #include <stdint.h>
  13
  14 // Useful defines
  15
  16 #define FLAG_E  0x80            // Entire
  17 #define FLAG_F  0x40            // Fast IRQ
  18 #define FLAG_H  0x20            // Half carry
  19 #define FLAG_I  0x10            // IRQ
  20 #define FLAG_N  0x08            // Negative
  21 #define FLAG_Z  0x04            // Zero
  22 #define FLAG_V  0x02            // oVerflow
  23 #define FLAG_C  0x01            // Carry
  24
  25 #define V6809_ASSERT_LINE_RESET         0x0001          // v6809 RESET line
  26 #define V6809_ASSERT_LINE_IRQ           0x0002          // v6809 IRQ line
  27 #define V6809_ASSERT_LINE_FIRQ          0x0004          // v6809 FIRQ line
  28 #define V6809_ASSERT_LINE_NMI           0x0008          // v6809 NMI line
  29 #define V6809_STATE_SYNC                        0x0010          // v6809 SYNC line
  30 #define V6809_STATE_ILLEGAL_INST        0x0020          // Illegal instruction executed flag
  31 //#define V6809_START_DEBUG_LOG EQU     0020h           // Debug log go (temporary!)
  32
  33 // Useful structs
  34
  35 struct V6809REGS
  36 {
  37         uint16_t pc;                                    // 6809 PC register
  38         uint16_t x;                                             // 6809 X index register
  39         uint16_t y;                                             // 6809 Y index register
  40         uint16_t s;                                             // 6809 System stack pointer
  41         uint16_t u;                                             // 6809 User stack pointer
  42         uint8_t cc;                                             // 6809 Condition Code register
  43         uint8_t a;                                              // 6809 A register
  44         uint8_t b;                                              // 6809 B register
  45         uint8_t dp;                                             // 6809 Direct Page register
  46 //      uint32_t clock;                                 // 6809 clock (@ 1 MHz, wraps at 71.5 minutes)
  47         uint64_t clock;                                 // 6809 clock (@ 1 MHz, wraps at 570842 years)
  48         uint8_t (* RdMem)(uint16_t);            // Address of uint8_t read routine
  49         void (* WrMem)(uint16_t, uint8_t);      // Address of uint8_t write routine
  50         uint32_t cpuFlags;                              // v6809 IRQ/RESET flags
  51         uint32_t clockOverrun;
  52 };
  53
  54 // Function prototypes
  55
  56 void Execute6809(V6809REGS *, uint32_t);                // Function to execute 6809 instructions
  57 uint64_t GetCurrentV6809Clock(void);                    // Get the clock of the currently executing CPU
  58 uint16_t GetCurrentV6809PC(void);                               // Get the PC of the currently executing CPU
  59 void SetLineOfCurrentV6809(uint32_t line);              // Set a line of the currently executing CPU
  60 void ClearLineOfCurrentV6809(uint32_t line);    // Clear a line of the currently executing CPU
  61
  62 #endif  // __V6809_H__
  63