memoria.cpp

#include "memoria.h"

using namespace std;

int32_t mem[MEM_SIZE];

void check_address_range(uint32_t address) {
	// endereco em bytes, memoria em words
	if ((address >> 2) > MEM_SIZE) {
		cout << "Erro: Endereco fora dos limites da memoria - " << address;
		exit(-1);
	}
}

int32_t lb(uint32_t address, int32_t kte) {
	auto target_addr = address + kte;

	check_address_range(target_addr);
	auto* pb = (int8_t*)&mem;

	return (*(pb + target_addr));
}

int32_t lbu(uint32_t address, int32_t kte) {
	auto target_addr = address + kte;

	check_address_range(target_addr);
	auto* pb = (uint8_t*)&mem;

	return (*(pb + target_addr));
}

int32_t lh(uint32_t address, int32_t kte) {
	auto target_addr = address + kte;

	check_address_range(target_addr);


	if ((target_addr % 2) != 0) {
		cout << "Erro: endereco de meia palavra desalinhado!" << endl;
		return -1;
	}
	auto  word = mem[target_addr >> 2];
	word = (word >> 8 * (target_addr & 2));

	return (word & 0xFFFF);
}

//int32_t lhu(uint32_t address, int32_t kte) {
//	uint32_t target_addr = address + kte;
//
//	check_address_range(target_addr);
//
//	if ((target_addr % 2) != 0) {
//		cout << "Erro: endereco de meia palavra desalinhado!";
//		return -1;
//	}
//
//	auto word = mem[target_addr];
//	word = (word >> 8 * (target_addr & 2));
//
//	return (word & 0xFFFF);
//}

int32_t lw(uint32_t address, int32_t kte) {
	auto target_addr = address + kte;

	check_address_range(target_addr);

	return mem[target_addr >> 2];
}



void sb(uint32_t address, int32_t kte, int8_t dado) {
	auto target_addr = address + kte;

	check_address_range(target_addr);


	auto* pb = (uint8_t*)&mem[target_addr >> 2];
	auto bi = (target_addr % 4);
	pb += bi;

	*pb = (uint8_t)dado;
}

void sh(uint32_t address, int32_t kte, int8_t dado) {
	auto target_addr = address + kte;

	check_address_range(target_addr);

	if ((target_addr % 2) != 0)
		cout << "Erro: endereco de meia palavra desalinhado!" << endl;

	uint16_t *ph = (uint16_t *)&mem[target_addr>>2];

	if (target_addr) ph++;

	*ph = (uint16_t)dado;
}

void sw(uint32_t address, int32_t kte, int32_t dado){
	auto target_address = address + kte;

	check_address_range(target_address);

	mem[target_address >> 2] = dado;

}