COSC530-RISC-V-Emulator-/DRAM.cpp at main · gardenqu/COSC530-RISC-V-Emulator- · GitHub

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#include "DRAM.h"
#include <iostream>
#include "Constants.h"


DRAM::DRAM() {
	// Allocate MEM_SIZE bytes, initialized to 0
	mem.resize(MEM_SIZE, 0);
}


uint32_t DRAM::load(uint32_t addr, uint32_t size)
{
	//std::cout << "DRAM::load called with size = " << size << ", addr = " << addr << std::endl;

	switch (size) {

		case BYTE_SIZE: return loadByte(addr);
		case HALF_WORD_SIZE_BITS: return loadHalf(addr);
		case WORD_SIZE_BITS: return loadWord(addr);
		default:
			std::cerr << "DRAM_Load: Error: invalid input!\n";
			break;


	}
	return 0;
}

void DRAM::store(uint32_t addr, uint32_t size, uint32_t value)
{

	switch (size) {
	case BYTE_SIZE: storeByte(addr, value);
		break;
	case HALF_WORD_SIZE_BITS: storeHalf(addr, value);
		break;
	case WORD_SIZE_BITS: storeWord(addr, value);
		break;
	default:
		std::cerr << "DRAM_Store: Error: invalid input!\n";
		break;
	}
}

uint32_t DRAM::getMemorySize()
{
	return MEM_SIZE;
}


/*Private Functions */

uint8_t DRAM::loadByte(uint32_t addr)
{
	return mem[addr];
}

void DRAM::storeByte(uint32_t addr, uint8_t value)
{
	mem[addr] = value;
}

uint16_t DRAM::loadHalf(uint32_t addr)
{
	return mem[addr]
		| (mem[addr+1]<<BYTE_SIZE);
}

void DRAM::storeHalf(uint32_t addr, uint16_t value)
{
	mem[addr] = value & 0xFF;
	mem[addr + 1] = (value >> BYTE_SIZE) & UINT8_MAX;
}

uint32_t DRAM::loadWord(uint32_t addr)
{
	return mem[addr]
		| (mem[addr+1]<<BYTE_SIZE)
		| (mem[addr+2]<<HALF_WORD_SIZE_BITS)
		|(mem[addr+3]<<THREE_BYTE_SIZE);
}

void DRAM::storeWord(uint32_t addr, uint32_t value)
{
	mem[addr] = value & 0xFF;
	mem[addr + 1] = (value>>BYTE_SIZE) & UINT8_MAX;
	mem[addr + 2] = (value>> HALF_WORD_SIZE_BITS) & UINT8_MAX;
	mem[addr + 3] = (value >> THREE_BYTE_SIZE) & UINT8_MAX;

}