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// license:BSD-3-Clause
// copyright-holders:Curt Coder
/**********************************************************************
RCA CDP1852 Byte-Wide Input/Output Port emulation
**********************************************************************
_____ _____
CSI/_CSI 1 |* \_/ | 24 Vdd
MODE 2 | | 23 _SR/SR
DI0 3 | | 22 DI7
DO0 4 | | 21 DO7
DI1 5 | | 20 DI6
DO1 6 | CDP1852 | 19 DO6
DI2 7 | | 18 DI5
DO2 8 | | 17 DO5
DI3 9 | | 16 DI4
DO3 10 | | 15 DO4
CLOCK 11 | | 14 _CLEAR
Vss 12 |_____________| 13 CS2
**********************************************************************/
#ifndef MAME_MACHINE_CDP1852_H
#define MAME_MACHINE_CDP1852_H
#pragma once
class cdp1852_device : public device_t
{
public:
// construction/destruction
cdp1852_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock = 0);
auto mode_cb() { return m_read_mode.bind(); }
auto sr_cb() { return m_write_sr.bind(); }
auto di_cb() { return m_read_data.bind(); }
auto do_cb() { return m_write_data.bind(); }
DECLARE_READ8_MEMBER(read);
DECLARE_WRITE8_MEMBER(write);
DECLARE_WRITE_LINE_MEMBER(clock_w);
uint8_t do_r() { return m_data; }
protected:
// device-level overrides
virtual void device_start() override;
virtual void device_reset() override;
private:
void set_sr_line(bool state);
TIMER_CALLBACK_MEMBER(update_do);
TIMER_CALLBACK_MEMBER(update_sr);
devcb_read_line m_read_mode;
devcb_write_line m_write_sr;
devcb_read8 m_read_data;
devcb_write8 m_write_data;
bool m_new_data; // new data written
u8 m_data; // data latch
bool m_clock_active; // input clock
bool m_sr; // service request flag
bool m_next_sr; // next value of service request flag
// timers
emu_timer *m_update_do_timer;
emu_timer *m_update_sr_timer;
};
DECLARE_DEVICE_TYPE(CDP1852, cdp1852_device)
#endif // MAME_MACHINE_CDP1852_H
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