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#include <cassert>
#include <cstdint>
#include <memory>
#include "mem.hpp"
namespace taller::avalon
{
mem::mem(std::uint32_t base, std::uint32_t size)
: base(base), mask(~(size - 1)),
block(std::make_unique<std::uint32_t[]>(size >> 2))
{
assert(!(size & 0b11) && !((size - 1) & size));
}
bool mem::read(std::uint32_t addr, std::uint32_t &data)
{
data = block[addr];
return ready();
}
bool mem::write(std::uint32_t addr, std::uint32_t data, unsigned byte_enable)
{
std::uint32_t bytes = 0;
if(byte_enable & 0b1000)
{
bytes |= 0xff << 24;
}
if(byte_enable & 0b0100)
{
bytes |= 0xff << 16;
}
if(byte_enable & 0b0010)
{
bytes |= 0xff << 8;
}
if(byte_enable & 0b0001)
{
bytes |= 0xff;
}
block[addr] = (data & bytes) | (block[addr] & ~bytes);
return ready();
}
bool mem::ready() noexcept
{
count = count > 0 ? count - 1 : 2;
return count == 0;
}
}
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