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// license:BSD-3-Clause
// copyright-holders:Sandro Ronco
// thanks-to:rfka01
/***************************************************************************
K233 16K Shared RAM
***************************************************************************/
#include "emu.h"
#include "k233.h"
/***************************************************************************
IMPLEMENTATION
***************************************************************************/
//**************************************************************************
// GLOBAL VARIABLES
//**************************************************************************
DEFINE_DEVICE_TYPE(DMV_K233, dmv_k233_device, "dmv_k233", "K233 16K Shared RAM")
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
//-------------------------------------------------
// dmv_k233_device - constructor
//-------------------------------------------------
dmv_k233_device::dmv_k233_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: device_t(mconfig, DMV_K233, tag, owner, clock)
, device_dmvslot_interface(mconfig, *this)
, m_enabled(false)
, m_ram(nullptr)
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void dmv_k233_device::device_start()
{
m_ram = machine().memory().region_alloc( "sharedram", 0x4000, 1, ENDIANNESS_LITTLE )->base();
// register for state saving
save_item(NAME(m_enabled));
save_pointer(NAME(m_ram), 0x4000);
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void dmv_k233_device::device_reset()
{
m_enabled = false;
}
void dmv_k233_device::io_write(int ifsel, offs_t offset, uint8_t data)
{
if (ifsel == 1)
m_enabled = !m_enabled;
}
//-------------------------------------------------
// read
//-------------------------------------------------
bool dmv_k233_device::read(offs_t offset, uint8_t &data)
{
if (m_enabled && offset >= 0xc000 && offset < 0x10000)
{
data = m_ram[offset & 0x3fff];
return true;
}
return false;
}
//-------------------------------------------------
// write
//-------------------------------------------------
bool dmv_k233_device::write(offs_t offset, uint8_t data)
{
if (m_enabled && offset >= 0xc000 && offset < 0x10000)
{
m_ram[offset & 0x3fff] = data;
return true;
}
return false;
}
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