// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/***************************************************************************
eeprom.c
Base class for EEPROM devices.
***************************************************************************/
#include "emu.h"
#include "machine/eeprom.h"
//#define VERBOSE 1
#include "logmacro.h"
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
//-------------------------------------------------
// eeprom_base_device - constructor
//-------------------------------------------------
eeprom_base_device::eeprom_base_device(const machine_config &mconfig, device_type devtype, const char *tag, device_t *owner)
: device_t(mconfig, devtype, tag, owner, 0),
device_nvram_interface(mconfig, *this),
m_region(*this, DEVICE_SELF),
m_cells(0),
m_address_bits(0),
m_data_bits(0),
m_default_data(nullptr),
m_default_data_size(0),
m_default_value(0),
m_default_value_set(false),
m_completion_time(attotime::zero)
{
// a 2ms write time is too long for rfjetsa
m_operation_time[WRITE_TIME] = attotime::from_usec(1750);
m_operation_time[WRITE_ALL_TIME] = attotime::from_usec(8000);
m_operation_time[ERASE_TIME] = attotime::from_usec(1000);
m_operation_time[ERASE_ALL_TIME] = attotime::from_usec(8000);
}
//-------------------------------------------------
// set_default_data - configuration helpers
// to set the default data
//-------------------------------------------------
eeprom_base_device& eeprom_base_device::size(int cells, int cellbits)
{
m_cells = cells;
m_data_bits = cellbits;
// compute address bits (validation checks verify cells was an even power of 2)
cells--;
m_address_bits = 0;
while (cells != 0)
{
cells >>= 1;
m_address_bits++;
}
return *this;
}
//-------------------------------------------------
// set_default_data - configuration helpers
// to set the default data
//-------------------------------------------------
eeprom_base_device& eeprom_base_device::default_data(const uint8_t *data, uint32_t size)
{
assert(m_data_bits == 8);
m_default_data = data;
m_default_data_size = size;
return *this;
}
eeprom_base_device& eeprom_base_device::default_data(const uint16_t *data, uint32_t size)
{
assert(m_data_bits == 16);
m_default_data = data;
m_default_data_size = size / 2;
return *this;
}
//-------------------------------------------------
// read - read data at the given address
//-------------------------------------------------
uint32_t eeprom_base_device::read(offs_t address)
{
if (!ready())
logerror("EEPROM: Read performed before previous operation completed!\n");
return internal_read(address);
}
//-------------------------------------------------
// write - write data at the given address
//-------------------------------------------------
void eeprom_base_device::write(offs_t address, uint32_t data)
{
if (!ready())
logerror("EEPROM: Write performed before previous operation completed!\n");
internal_write(address, data);
m_completion_time = machine().time() + m_operation_time[WRITE_TIME];
}
//-------------------------------------------------
// write_all - write data at all addresses
// (assumes an erase has previously been
// performed)
//-------------------------------------------------
void eeprom_base_device::write_all(uint32_t data)
{
if (!ready())
logerror("EEPROM: Write all performed before previous operation completed!\n");
for (offs_t address = 0; address < (1 << m_address_bits); address++)
internal_write(address, internal_read(address) & data);
m_completion_time = machine().time() + m_operation_time[WRITE_ALL_TIME];
}
//-------------------------------------------------
// erase - erase data at the given address
//-------------------------------------------------
void eeprom_base_device::erase(offs_t address)
{
if (!ready())
logerror("EEPROM: Erase performed before previous operation completed!\n");
internal_write(address, ~0);
m_completion_time = machine().time() + m_operation_time[ERASE_TIME];
}
//-------------------------------------------------
// erase_all - erase data at all addresses
//-------------------------------------------------
void eeprom_base_device::erase_all()
{
if (!ready())
logerror("EEPROM: Erase all performed before previous operation completed!\n");
for (offs_t address = 0; address < (1 << m_address_bits); address++)
internal_write(address, ~0);
m_completion_time = machine().time() + m_operation_time[ERASE_ALL_TIME];
}
//-------------------------------------------------
// device_validity_check - perform validity checks
// on this device
//-------------------------------------------------
void eeprom_base_device::device_validity_check(validity_checker &valid) const
{
// ensure the number of cells is an even power of 2
if (m_cells != (1 << m_address_bits))
osd_printf_error("Invalid EEPROM size %d specified\n", m_cells);
// ensure only the sizes we support are requested
if (m_data_bits != 8 && m_data_bits != 16)
osd_printf_error("Invalid EEPROM data width %d specified\n", m_data_bits);
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void eeprom_base_device::device_start()
{
uint32_t size = (m_data_bits == 8 ? 1 : 2) << m_address_bits;
m_data = std::make_unique<uint8_t []>(size);
// save states
save_item(NAME(m_completion_time));
save_pointer(NAME(m_data), size);
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void eeprom_base_device::device_reset()
{
// reset any pending operations
m_completion_time = attotime::zero;
}
//-------------------------------------------------
// nvram_default - called to initialize NVRAM to
// its default state
//-------------------------------------------------
void eeprom_base_device::nvram_default()
{
uint32_t eeprom_length = 1 << m_address_bits;
uint32_t eeprom_bytes = eeprom_length * m_data_bits / 8;
// initialize to the default value
uint32_t default_value = m_default_value_set ? m_default_value : ~0;
for (offs_t offs = 0; offs < eeprom_length; offs++)
internal_write(offs, default_value);
// handle hard-coded data from the driver
if (m_default_data != nullptr)
{
osd_printf_verbose("Warning: Driver-specific EEPROM defaults are going away soon.\n");
for (offs_t offs = 0; offs < m_default_data_size; offs++)
{
if (m_data_bits == 8)
internal_write(offs, static_cast<const u8 *>(m_default_data)[offs]);
else
internal_write(offs, static_cast<const u16 *>(m_default_data)[offs]);
}
}
// populate from a memory region if present
if (m_region.found())
{
if (m_region->bytes() != eeprom_bytes)
fatalerror("eeprom region '%s' wrong size (expected size = 0x%X)\n", tag(), eeprom_bytes);
if (m_data_bits == 8 && m_region->bytewidth() != 1)
fatalerror("eeprom region '%s' needs to be an 8-bit region\n", tag());
if (m_data_bits == 16 && m_region->bytewidth() != 2)
fatalerror("eeprom region '%s' needs to be a 16-bit region\n", tag());
osd_printf_verbose("Loading data from EEPROM region '%s'\n", tag());
memcpy(&m_data[0], m_region->base(), eeprom_bytes);
}
}
//-------------------------------------------------
// nvram_read - called to read NVRAM from the
// .nv file
//-------------------------------------------------
void eeprom_base_device::nvram_read(emu_file &file)
{
uint32_t eeprom_length = 1 << m_address_bits;
uint32_t eeprom_bytes = eeprom_length * m_data_bits / 8;
file.read(&m_data[0], eeprom_bytes);
}
//-------------------------------------------------
// nvram_write - called to write NVRAM to the
// .nv file
//-------------------------------------------------
void eeprom_base_device::nvram_write(emu_file &file)
{
uint32_t eeprom_length = 1 << m_address_bits;
uint32_t eeprom_bytes = eeprom_length * m_data_bits / 8;
file.write(&m_data[0], eeprom_bytes);
}
//-------------------------------------------------
// internal_read - read data at the given address
//-------------------------------------------------
uint32_t eeprom_base_device::internal_read(offs_t address)
{
if (m_data_bits == 16)
return m_data[address * 2] | (m_data[address * 2 + 1] << 8);
else
return m_data[address];
}
//-------------------------------------------------
// internal_write - write data at the given
// address
//-------------------------------------------------
void eeprom_base_device::internal_write(offs_t address, uint32_t data)
{
if (m_data_bits == 16)
{
m_data[address * 2] = data;
m_data[address * 2 + 1] = data >> 8;
} else
m_data[address] = data;
}