instruction.c File Reference

#include "instruction.h"
#include "../chip8.h"
#include "../common.h"
#include "../decode.h"
#include "../font.h"
#include "../graphics.h"
#include "exception.h"
#include <stdlib.h>
#include <string.h>

Macros
#define	C8_VERBOSE(c)   (c->flags & C8_FLAG_VERBOSE)
#define	C8_SCHIP_EXCLUSIVE(c)
#define	C8_XOCHIP_EXCLUSIVE(c)
#define	C8_QUIRK_VF_RESET(c)
#define	C8_QUIRK_MEMORY(c)
#define	C8_QUIRK_SHIFTING(c)

Functions
int	c8_parse_instruction (C8 *c8)
	Execute the instruction at c8->pc
void	print_binary (unsigned int n)

Detailed Description

Note

NOT EXPORTED

This file contains the implementation of the instruction parsing and execution for the CHIP-8 interpreter.

Macro Definition Documentation

C8_QUIRK_MEMORY

#define C8_QUIRK_MEMORY

(

c

)

Value:

    if (c->flags & C8_FLAG_QUIRK_MEMORY) {                                                         \
        c8->I = (c8->I + x + 1) & 0xFFF;                                                           \
    }

C8_QUIRK_SHIFTING

#define C8_QUIRK_SHIFTING

(

c

)

Value:

    if (c->flags & C8_FLAG_QUIRK_SHIFTING) {                                                       \
        y = x;                                                                                     \
    }

C8_QUIRK_VF_RESET

#define C8_QUIRK_VF_RESET

(

c

)

Value:

    if (c->flags & C8_FLAG_QUIRK_VF_RESET) {                                                       \
        c->V[0xF] = 0;                                                                             \
    }

C8_SCHIP_EXCLUSIVE

#define C8_SCHIP_EXCLUSIVE

(

c

)

Value:

    if (c->mode == C8_MODE_CHIP8) {                                                                \
        fprintf(stderr, "SCHIP instruction detected in CHIP-8 mode.\n");                           \
        return C8_INVALID_STATE_EXCEPTION;                                                         \
    }

C8_VERBOSE

#define C8_VERBOSE

(

c

)

(c->flags & C8_FLAG_VERBOSE)

C8_XOCHIP_EXCLUSIVE

#define C8_XOCHIP_EXCLUSIVE

(

c

)

Value:

    if (c->mode != C8_MODE_XOCHIP) {                                                               \
        const char* modeStr = (c->mode == C8_MODE_CHIP8) ? "CHIP-8" : "SCHIP";                     \
        fprintf(stderr, "XOCHIP instruction detected in %s mode.\n", modeStr);                     \
        return C8_INVALID_STATE_EXCEPTION;                                                         \
    }

Function Documentation

c8_parse_instruction()

int c8_parse_instruction

(

C8 *

c8

)

Execute the instruction at c8->pc

This function parses and executes the instruction at the current program counter.

If verbose flag is set, this will print the instruction to stdout as well.

Parameters

c8	the C8 to execute the instruction from

Returns

amount to increase the program counter, or an exception code if an error occurs.

print_binary()

void print_binary

(

unsigned int

n

)