// 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"
//**************************************************************************
// INTERFACE CONFIGURATION MACROS
//**************************************************************************
#define MCFG_I8251_TXD_HANDLER(_devcb) \
devcb = &downcast<i8251_device &>(*device).set_txd_handler(DEVCB_##_devcb);
#define MCFG_I8251_DTR_HANDLER(_devcb) \
devcb = &downcast<i8251_device &>(*device).set_dtr_handler(DEVCB_##_devcb);
#define MCFG_I8251_RTS_HANDLER(_devcb) \
devcb = &downcast<i8251_device &>(*device).set_rts_handler(DEVCB_##_devcb);
#define MCFG_I8251_RXRDY_HANDLER(_devcb) \
devcb = &downcast<i8251_device &>(*device).set_rxrdy_handler(DEVCB_##_devcb);
#define MCFG_I8251_TXRDY_HANDLER(_devcb) \
devcb = &downcast<i8251_device &>(*device).set_txrdy_handler(DEVCB_##_devcb);
#define MCFG_I8251_TXEMPTY_HANDLER(_devcb) \
devcb = &downcast<i8251_device &>(*device).set_txempty_handler(DEVCB_##_devcb);
#define MCFG_I8251_SYNDET_HANDLER(_devcb) \
devcb = &downcast<i8251_device &>(*device).set_syndet_handler(DEVCB_##_devcb);
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 <class Object> devcb_base &set_txd_handler(Object &&cb) { return m_txd_handler.set_callback(std::forward<Object>(cb)); }
template <class Object> devcb_base &set_dtr_handler(Object &&cb) { return m_dtr_handler.set_callback(std::forward<Object>(cb)); }
template <class Object> devcb_base &set_rts_handler(Object &&cb) { return m_rts_handler.set_callback(std::forward<Object>(cb)); }
template <class Object> devcb_base &set_rxrdy_handler(Object &&cb) { return m_rxrdy_handler.set_callback(std::forward<Object>(cb)); }
template <class Object> devcb_base &set_txrdy_handler(Object &&cb) { return m_txrdy_handler.set_callback(std::forward<Object>(cb)); }
template <class Object> devcb_base &set_txempty_handler(Object &&cb) { return m_txempty_handler.set_callback(std::forward<Object>(cb)); }
template <class Object> devcb_base &set_syndet_handler(Object &&cb) { return m_syndet_handler.set_callback(std::forward<Object>(cb)); }
DECLARE_READ8_MEMBER(data_r);
DECLARE_WRITE8_MEMBER(data_w);
DECLARE_READ8_MEMBER(status_r);
DECLARE_WRITE8_MEMBER(control_w);
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);
/// TODO: REMOVE THIS
void receive_character(uint8_t ch);
/// TODO: this shouldn't be public
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
};
protected:
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 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 v53_scu_device : public i8251_device
{
public:
// construction/destruction
v53_scu_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
DECLARE_WRITE8_MEMBER(command_w);
DECLARE_WRITE8_MEMBER(mode_w);
};
// device type definition
DECLARE_DEVICE_TYPE(I8251, i8251_device)
DECLARE_DEVICE_TYPE(V53_SCU, v53_scu_device)
#endif // MAME_MACHINE_I8251_H