jb302@34: /* mem.h */
jb302@34: #ifndef MEM_H
jb302@34: #define MEM_H
jb302@34: 
jb302@34: #if defined MAIN
jb302@34: #define EXTERN
jb302@34: #else
jb302@34: #define EXTERN extern
jb302@34: #endif
jb302@34: 
jb302@34: /* 8 bit register encodings */
jb302@34: #define R0   (0 | (get_flag(0) << 3))
jb302@34: #define R1   (1 | (get_flag(0) << 3))
jb302@34: #define R2   (2 | (get_flag(0) << 3))
jb302@34: #define R3   (3 | (get_flag(0) << 3))
jb302@34: #define DPH  4
jb302@34: #define SPH  5
jb302@34: #define PCH  6 
jb302@34: #define TMPH 7
jb302@34: #define DPL  12
jb302@34: #define SPL  13
jb302@34: #define PCL  14
jb302@34: #define TMPL 15
jb302@34: 
jb302@34: /* 16 bit register encodings */ 
jb302@34: #define DPTR 0 
jb302@34: #define SP   1 
jb302@34: #define PC   2 
jb302@34: #define TMP  3 
jb302@34:  
jb302@34: /* flag bits numbered from LSB -> MSB 
jb302@34:  *  7 6 5  4 3 2  1  0 
jb302@34:  *  C Z AC P S OV IE BS */
jb302@34: #define BS 0
jb302@34: #define IE 1
jb302@34: #define OV 2
jb302@34: #define S  3
jb302@34: #define P  4
jb302@34: #define AC 5
jb302@34: #define Z  6
jb302@34: #define C  7
jb302@34: 
jb302@34: /* for getting and setting flags */ 
jb302@34: #define GBIT(byte, n) (byte & (0x01 << n) ? 1 : 0)  
jb302@34: #define SBIT(byte, n) (byte | (0x01 << n)) 
jb302@34: #define CBIT(byte, n) (byte ^ (0x01 << n)) 
jb302@34: 
jb302@34: /* for making and breaking 16 bit values */
jb302@34: #define MWIDE(high, low) (low | (high << 8))
jb302@34: #define GHIGH(wide) ((wide >> 8) & 0xFF)
jb302@34: #define GLOW(wide) (wide & 0xFF) 
jb302@34: 
jb302@34: typedef unsigned char BYTE;
jb302@34: typedef unsigned short WIDE;
jb302@34: 
jb302@34: /* these are needed for some operations */
jb302@34: EXTERN BYTE tmpb;
jb302@34: EXTERN WIDE tmpw;
jb302@34: 
jb302@34: EXTERN BYTE IR;
jb302@34: EXTERN BYTE A;
jb302@34: EXTERN BYTE flags;
jb302@34: 
jb302@34: /*  0x00 0b0000 r0 bank 0
jb302@34:     0x01 0b0001 r1 bank 0
jb302@34:     0x02 0b0010 r2 bank 0
jb302@34:     0x03 0b0011 r3 bank 0
jb302@34:     0x04 0b0100 dph
jb302@34:     0x05 0b0101 sph
jb302@34:     0x06 0b0110 pch
jb302@34:     0x07 0b0111 tmph
jb302@34:     0x08 0b1000 r0 bank 1
jb302@34:     0x09 0b1001 r1 bank 1
jb302@34:     0x0A 0b1010 r2 bank 1
jb302@34:     0x0B 0b1011 r3 bank 1
jb302@34:     0x0C 0b1100 dpl
jb302@34:     0x0D 0b1101 spl
jb302@34:     0x0E 0b1110 pcl
jb302@34:     0x0F 0b1111 tmpl */
jb302@34: EXTERN BYTE regs[0x10];
jb302@34: 
jb302@34: /* 64K Von Neumann memory */
jb302@34: EXTERN BYTE mem[0x10000];
jb302@34: 
jb302@34: /* functions to dealing with flags */
jb302@34: EXTERN BYTE
jb302@34: get_flag(BYTE flag);
jb302@34: 
jb302@34: EXTERN void
jb302@34: set_flag(BYTE flag, BYTE on);
jb302@34: 
jb302@34: EXTERN void
jb302@34: set_zp(BYTE val);
jb302@34: 
jb302@34: /* this function a byte and returns a byte
jb302@34:  * with zero and parity flags set or unset.
jb302@34:  * result should be or'd with flags reg */
jb302@34: EXTERN BYTE
jb302@34: gen_flags(BYTE val);
jb302@34: 
jb302@34: /* functions for dealing with 16-bit registers
jb302@34:  * access the 16 bit registers.
jb302@34:  * register map for these function:
jb302@34:  *   0b00 dptr
jb302@34:  *   0b01 sp
jb302@34:  *   0b10 pc
jb302@34:  *   0b11 tmp */
jb302@34: EXTERN WIDE
jb302@34: get_wide(BYTE reg);
jb302@34: 
jb302@34: EXTERN void
jb302@34: set_wide(BYTE reg, WIDE val);
jb302@34: 
jb302@34: /* functions to fetch data at PC */
jb302@34: EXTERN void
jb302@34: inc_pc(BYTE n);
jb302@34: 
jb302@34: EXTERN BYTE
jb302@34: fetch();
jb302@34: 
jb302@34: EXTERN WIDE
jb302@34: fetch_wide();
jb302@34: 
jb302@34: /* for mapping the register encoding in the instruction
jb302@34:  * set to the register address */
jb302@34: EXTERN BYTE
jb302@34: get_reg(BYTE reg);
jb302@34: 
jb302@34: EXTERN void
jb302@34: set_reg(BYTE reg, BYTE val);
jb302@34: 
jb302@34: 
jb302@34: #endif