102 lines
2.2 KiB
C
102 lines
2.2 KiB
C
//
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// Created by william on 10/15/23.
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//
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#ifndef CPU_CPU_H
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#define CPU_CPU_H
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#include <stdbool.h>
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#include "memory.h"
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// Reference: https://www.nesdev.org/wiki/Status_flags
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#define CPU_STATUS_CARRY_MASK 0x01
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#define CPU_STATUS_ZERO_MASK 0x02
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#define CPU_STATUS_INTERRUPT_DISABLE_MASK 0x04
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#define CPU_STATUS_DECIMAL_MASK 0x08
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#define CPU_STATUS_B_MASK 0x10
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#define CPU_STATUS_OVERFLOW_MASK 0x40
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#define CPU_STATUS_NEGATIVE_MASK 0x80
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#define CPU_STACK_ADDR 0x0100
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/**
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* Gets a flag from the CPU registers.
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*
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* @param system The system
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* @param mask The flag mask
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* @return The value of the flag.
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*/
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bool system_get_flag(System *system, byte mask);
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static inline bool cpu_get_flag(CPU *cpu, byte mask) {
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return cpu->status & mask;
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}
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/**
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* Sets a flag in the CPU registers.
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*
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* @param system The system
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* @param mask The flag mask
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* @param set If the flag is set or not
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*/
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void system_set_flag(System *system, byte mask, bool set);
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/**
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* Gets the next byte in the program.
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* Increases the system program counter.
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*
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* @param system The system
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* @return The value of the next byte.
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*/
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byte cpu_get_next_byte(System *system);
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/**
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* Gets the next word in the program.
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* Increases the system program counter by 2.
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*
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* @param system The system
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* @return The value of the next word.
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*/
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word cpu_get_next_word(System *system);
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/**
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* Pushes a byte in to the stack.
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*
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* @param system The system
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* @param value The value to push to the stack
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*/
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void cpu_stack_push(System *system, byte value);
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/**
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* Pushes the execution context to the stack.
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* This includes the program counter and the CPU status.
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*
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* @param system The system
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*/
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void cpu_stack_push_context(System *system);
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/**
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* Pops a byte from the stack.
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*
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* @param system The system
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* @return The value of the byte
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*/
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byte cpu_stack_pop(System *system);
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/**
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* Pops an execution context from the stack and overwrite the current context.
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* This includes the program counter and the CPU status.
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*
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* @param system The system
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*/
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void cpu_stack_pop_context(System *system);
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/**
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* Adds wait cycles to the CPU.
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*
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* @param cycle_count The number of cycle to wait
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*/
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void cpu_add_cycles(System *system, unsigned int cycle_count);
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#endif //CPU_CPU_H
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