// license:BSD-3-Clause // copyright-holders:Aaron Giles /********************************************************************** DALLAS DS2404 RTC + BACKUP RAM **********************************************************************/ #ifndef MAME_MACHINE_DS2404_H #define MAME_MACHINE_DS2404_H #pragma once class ds2404_device : public device_t, public device_nvram_interface { public: // construction/destruction ds2404_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock); // inline configuration helpers void ref_year(uint32_t year) { m_ref_year = year; } void ref_month(uint8_t month) { m_ref_month = month; } void ref_day(uint8_t day) { m_ref_day = day; } /* 1-wire interface reset */ void _1w_reset_w(uint8_t data); /* 3-wire interface reset */ void _3w_reset_w(uint8_t data); uint8_t data_r(); void data_w(uint8_t data); void clk_w(uint8_t data); 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 bool nvram_read(util::read_stream &file) override; virtual bool nvram_write(util::write_stream &file) override; TIMER_CALLBACK_MEMBER(timer_tick); private: void rom_cmd(uint8_t cmd); void cmd(uint8_t cmd); uint8_t readmem(); void writemem(uint8_t value); enum STATE { STATE_IDLE = 1, /* waiting for ROM command, in 1-wire mode */ STATE_COMMAND, /* waiting for memory command */ STATE_ADDRESS1, /* waiting for address bits 0-7 */ STATE_ADDRESS2, /* waiting for address bits 8-15 */ STATE_OFFSET, /* waiting for ending offset */ STATE_INIT_COMMAND, STATE_READ_MEMORY, /* Read Memory command active */ STATE_WRITE_SCRATCHPAD, /* Write Scratchpad command active */ STATE_READ_SCRATCHPAD, /* Read Scratchpad command active */ STATE_COPY_SCRATCHPAD /* Copy Scratchpad command active */ }; emu_timer *m_tick_timer; // configuration state uint32_t m_ref_year; uint8_t m_ref_month; uint8_t m_ref_day; uint16_t m_address; uint16_t m_offset; uint16_t m_end_offset; uint8_t m_a1; uint8_t m_a2; uint8_t m_sram[512]; /* 4096 bits */ uint8_t m_ram[32]; /* scratchpad ram, 256 bits */ uint8_t m_rtc[5]; /* 40-bit RTC counter */ STATE m_state[8]; int m_state_ptr; }; DECLARE_DEVICE_TYPE(DS2404, ds2404_device) #endif // MAME_MACHINE_DS2404_H