// license:BSD-3-Clause
// copyright-holders:Sergey Svishchev
/***************************************************************************
KR1601RR1 1024x4 bit EAROM
Same geometry as GI ER2401, but not pin-compatible.
To do:
- realistic timing esp. for ERASE_ALL
- alternate wirings
***************************************************************************/
#include "emu.h"
#include "kr1601rr1.h"
#include <algorithm>
#define LOG_GENERAL (1U << 0)
#define VERBOSE (LOG_GENERAL)
//#define LOG_OUTPUT_FUNC printf
#include "logmacro.h"
DEFINE_DEVICE_TYPE(KR1601RR1, kr1601rr1_device, "kr1601rr1", "KR1601RR1 EAROM")
//-------------------------------------------------
// ctor
//-------------------------------------------------
kr1601rr1_device::kr1601rr1_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: device_t(mconfig, KR1601RR1, tag, owner, clock)
, device_nvram_interface(mconfig, *this)
{
}
uint8_t kr1601rr1_device::read(offs_t offset)
{
assert(EAROM_SIZE > offset);
if (m_earom_mode == EAROM_READ)
{
LOG("earom R %03x == %x\n", offset, m_earom[offset] & 15);
return m_earom[offset] & 15;
}
else return 0;
}
/*
* wiring hardcoded for ms6102:
*
* b7..b4 = CS _PR _ER RD
* b3..b0 = data
*/
void kr1601rr1_device::write(offs_t offset, uint8_t data)
{
assert(EAROM_SIZE > offset);
switch (data >> 4)
{
case 0x0: case 0x1: case 0x2: case 0x3:
case 0x4: case 0x5: case 0x6: case 0x7:
m_earom_mode = EAROM_IDLE;
break;
case 0x8:
m_earom_mode = EAROM_ERASE;
break;
case 0xa:
m_earom_mode = EAROM_WRITE;
break;
case 0xc:
m_earom_mode = EAROM_ERASE_ALL;
break;
case 0xf:
m_earom_mode = EAROM_READ;
break;
}
LOG("earom new mode = %u (from %02X)\n", m_earom_mode, data);
switch (m_earom_mode)
{
case EAROM_WRITE:
LOG("earom W %03x <- %x\n", offset, data & 15);
m_earom[offset] |= (data & 15);
break;
case EAROM_ERASE:
LOG("earom erase %03x\n", offset);
m_earom[offset] = 0;
break;
case EAROM_ERASE_ALL:
LOG("earom erase all\n");
std::fill(std::begin(m_earom), std::end(m_earom), 0);
break;
default:
break;
}
}
//-------------------------------------------------
// nvram_default - called to initialize NVRAM to
// its default state
//-------------------------------------------------
void kr1601rr1_device::nvram_default()
{
std::fill(std::begin(m_earom), std::end(m_earom), 0);
}
//-------------------------------------------------
// nvram_read - called to read NVRAM from the
// .nv file
//-------------------------------------------------
void kr1601rr1_device::nvram_read(emu_file &file)
{
file.read(m_earom, EAROM_SIZE);
}
//-------------------------------------------------
// nvram_write - called to write NVRAM to the
// .nv file
//-------------------------------------------------
void kr1601rr1_device::nvram_write(emu_file &file)
{
file.write(m_earom, EAROM_SIZE);
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void kr1601rr1_device::device_start()
{
/* register for save states */
save_item(NAME(m_earom));
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void kr1601rr1_device::device_reset()
{
m_earom_mode = EAROM_IDLE;
}