cpu/cpu.h at master · kevinms/cpu · GitHub

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#ifndef __CPU_H
#define __CPU_H

#include <inttypes.h>

/*
 * Registers:
 *
 * r0  to r10      General Purpose
 *        r11  sp  Stack Pointer
 *        r12  ba  Base Address
 *        r13  fl  CPU Flags
 *        r14  c1  Timer 1 Counter
 *        r15  c2  Timer 2 Counter
 */
#define R_SP 11
#define R_BA 12
#define R_FL 13
#define R_C1 14
#define R_C2 15

#define NUM_REGISTERS 16

struct cpuState {
	/*
	 * Memory Mapped I/O:
	 */
	uint32_t mmapIOstart;
	uint32_t mmapIOend;

	/*
	 * Interrupts.
	 */
	uint32_t intGlobalControl;
	uint32_t intPending;
	uint32_t intControl;
	uint32_t intVector[32];

	/*
	 * Timers (counters).
	 */
	uint32_t timerTerminalCount1;
	uint32_t timerControl1;
	uint32_t timerTerminalCount2;
	uint32_t timerControl2;

	/*
	 * Registers and memory.
	 */
	uint32_t	r[NUM_REGISTERS], pc;
	uint32_t	memSize;
	uint8_t		*mem;
	char		*memoryFile;

	/*
	 * Helper for flags register.
	 */
	struct flags {
		uint32_t n : 1, // negative
				 z : 1, // zero
				 o : 1, // overflow
				 c : 1; // carry
	} *flags;

	uint64_t 	ic;
	uint32_t 	nextPC;
	uint32_t	startingPC;
	uint64_t	maxCycles;

	char		msg[4096];
};

/*
 * Temporary stores decoded instructions.
 */
struct instruction {
	uint8_t op;
	uint8_t mode;
	uint8_t reg0;
	uint8_t reg1;

	uint32_t raw2;
	uint32_t opr0, opr1, opr2;
};

#endif /* __CPU_H */