// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/**********************************************************************
DALLAS DS2404
RTC + BACKUP RAM
**********************************************************************/
#pragma once
#ifndef __DS2404_H__
#define __DS2404_H__
#include "emu.h"
/***************************************************************************
DEVICE CONFIGURATION MACROS
***************************************************************************/
#define MCFG_DS2404_ADD(_tag, _ref_year, _ref_month, _ref_day) \
MCFG_DEVICE_ADD(_tag, DS2404, 0) \
MCFG_DS2404_REF_YEAR(_ref_year) \
MCFG_DS2404_REF_MONTH(_ref_month) \
MCFG_DS2404_REF_DAY(_ref_day)
#define MCFG_DS2404_REF_YEAR(_ref_year) \
ds2404_device::static_set_ref_year(*device, _ref_year);
#define MCFG_DS2404_REF_MONTH(_ref_month) \
ds2404_device::static_set_ref_month(*device, _ref_month);
#define MCFG_DS2404_REF_DAY(_ref_day) \
ds2404_device::static_set_ref_day(*device, _ref_day);
//**************************************************************************
// TYPE DEFINITIONS
//**************************************************************************
// ======================> ds2404_device
class ds2404_device : public device_t,
public device_nvram_interface
{
public:
// construction/destruction
ds2404_device(const machine_config &mconfig, std::string tag, device_t *owner, UINT32 clock);
// inline configuration helpers
static void static_set_ref_year(device_t &device, UINT32 m_ref_year);
static void static_set_ref_month(device_t &device, UINT8 m_ref_month);
static void static_set_ref_day(device_t &device, UINT8 m_ref_day);
/* 1-wire interface reset */
DECLARE_WRITE8_MEMBER(ds2404_1w_reset_w);
/* 3-wire interface reset */
DECLARE_WRITE8_MEMBER(ds2404_3w_reset_w);
DECLARE_READ8_MEMBER(ds2404_data_r);
DECLARE_WRITE8_MEMBER(ds2404_data_w);
DECLARE_WRITE8_MEMBER(ds2404_clk_w);
protected:
// device-level overrides
virtual void device_start() override;
virtual void device_reset() override { }
virtual void device_post_load() override { }
virtual void device_clock_changed() override { }
// device_nvram_interface overrides
virtual void nvram_default() override;
virtual void nvram_read(emu_file &file) override;
virtual void nvram_write(emu_file &file) override;
virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
private:
void ds2404_rom_cmd(UINT8 cmd);
void ds2404_cmd(UINT8 cmd);
UINT8 ds2404_readmem();
void ds2404_writemem(UINT8 value);
enum DS2404_STATE
{
DS2404_STATE_IDLE = 1, /* waiting for ROM command, in 1-wire mode */
DS2404_STATE_COMMAND, /* waiting for memory command */
DS2404_STATE_ADDRESS1, /* waiting for address bits 0-7 */
DS2404_STATE_ADDRESS2, /* waiting for address bits 8-15 */
DS2404_STATE_OFFSET, /* waiting for ending offset */
DS2404_STATE_INIT_COMMAND,
DS2404_STATE_READ_MEMORY, /* Read Memory command active */
DS2404_STATE_WRITE_SCRATCHPAD, /* Write Scratchpad command active */
DS2404_STATE_READ_SCRATCHPAD, /* Read Scratchpad command active */
DS2404_STATE_COPY_SCRATCHPAD /* Copy Scratchpad command active */
};
emu_timer *m_tick_timer;
// configuration state
UINT32 m_ref_year;
UINT8 m_ref_month;
UINT8 m_ref_day;
UINT16 m_address;
UINT16 m_offset;
UINT16 m_end_offset;
UINT8 m_a1;
UINT8 m_a2;
UINT8 m_sram[512]; /* 4096 bits */
UINT8 m_ram[32]; /* scratchpad ram, 256 bits */
UINT8 m_rtc[5]; /* 40-bit RTC counter */
DS2404_STATE m_state[8];
int m_state_ptr;
};
// device type definition
extern const device_type DS2404;
#endif /* __DS2404_H__ */