// license:BSD-3-Clause // copyright-holders:smf /********************************************************************* i8251.h Intel 8251 Universal Synchronous/Asynchronous Receiver Transmitter code *********************************************************************/ #ifndef MAME_MACHINE_I8251_H #define MAME_MACHINE_I8251_H #pragma once #include "diserial.h" class i8251_device : public device_t, public device_serial_interface { public: // construction/destruction i8251_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock); // configuration helpers template devcb_base &set_txd_handler(Object &&cb) { return m_txd_handler.set_callback(std::forward(cb)); } template devcb_base &set_dtr_handler(Object &&cb) { return m_dtr_handler.set_callback(std::forward(cb)); } template devcb_base &set_rts_handler(Object &&cb) { return m_rts_handler.set_callback(std::forward(cb)); } template devcb_base &set_rxrdy_handler(Object &&cb) { return m_rxrdy_handler.set_callback(std::forward(cb)); } template devcb_base &set_txrdy_handler(Object &&cb) { return m_txrdy_handler.set_callback(std::forward(cb)); } template devcb_base &set_txempty_handler(Object &&cb) { return m_txempty_handler.set_callback(std::forward(cb)); } template devcb_base &set_syndet_handler(Object &&cb) { return m_syndet_handler.set_callback(std::forward(cb)); } auto txd_handler() { return m_txd_handler.bind(); } auto dtr_handler() { return m_dtr_handler.bind(); } auto rts_handler() { return m_rts_handler.bind(); } auto rxrdy_handler() { return m_rxrdy_handler.bind(); } auto txrdy_handler() { return m_txrdy_handler.bind(); } auto txempty_handler() { return m_txempty_handler.bind(); } auto syndet_handler() { return m_syndet_handler.bind(); } uint8_t data_r(); void data_w(uint8_t data); uint8_t status_r(); void control_w(uint8_t data); virtual uint8_t read(offs_t offset); virtual void write(offs_t offset, uint8_t data); DECLARE_WRITE_LINE_MEMBER( write_rxd ); DECLARE_WRITE_LINE_MEMBER( write_cts ); DECLARE_WRITE_LINE_MEMBER( write_dsr ); DECLARE_WRITE_LINE_MEMBER( write_txc ); DECLARE_WRITE_LINE_MEMBER( write_rxc ); DECLARE_READ_LINE_MEMBER(txrdy_r); protected: enum { I8251_STATUS_FRAMING_ERROR = 0x20, I8251_STATUS_OVERRUN_ERROR = 0x10, I8251_STATUS_PARITY_ERROR = 0x08, I8251_STATUS_TX_EMPTY = 0x04, I8251_STATUS_RX_READY = 0x02, I8251_STATUS_TX_READY = 0x01 }; i8251_device( const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock); // device-level overrides virtual void device_start() override; virtual void device_reset() override; void command_w(uint8_t data); void mode_w(uint8_t data); void receive_character(uint8_t ch); void update_rx_ready(); void update_tx_ready(); void update_tx_empty(); void transmit_clock(); void receive_clock(); bool is_tx_enabled() const; void check_for_tx_start(); void start_tx(); enum { I8251_EXPECTING_MODE = 0x01, I8251_EXPECTING_SYNC_BYTE = 0x02, I8251_DELAYED_TX_EN = 0x04 }; private: devcb_write_line m_txd_handler; devcb_write_line m_dtr_handler; devcb_write_line m_rts_handler; devcb_write_line m_rxrdy_handler; devcb_write_line m_txrdy_handler; devcb_write_line m_txempty_handler; devcb_write_line m_syndet_handler; /* flags controlling how i8251_control_w operates */ uint8_t m_flags; /* offset into sync_bytes used during sync byte transfer */ uint8_t m_sync_byte_offset; /* number of sync bytes written so far */ uint8_t m_sync_byte_count; /* the sync bytes written */ uint8_t m_sync_bytes[2]; /* status of i8251 */ uint8_t m_status; uint8_t m_command; /* mode byte - bit definitions depend on mode - e.g. synchronous, asynchronous */ uint8_t m_mode_byte; int m_cts; int m_dsr; int m_rxd; int m_rxc; int m_txc; int m_rxc_count; int m_txc_count; int m_br_factor; /* data being received */ uint8_t m_rx_data; /* tx buffer */ uint8_t m_tx_data; }; class v5x_scu_device : public i8251_device { public: // construction/destruction v5x_scu_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock); virtual uint8_t read(offs_t offset) override; virtual void write(offs_t offset, uint8_t data) override; protected: virtual void device_start() override; virtual void device_reset() override; // TODO: currently unimplemented interrupt masking u8 simk_r() { return m_simk; } void simk_w(u8 data) { m_simk = data; } private: u8 m_simk; }; // device type definition DECLARE_DEVICE_TYPE(I8251, i8251_device) DECLARE_DEVICE_TYPE(V5X_SCU, v5x_scu_device) #endif // MAME_MACHINE_I8251_H