blob: 81633923adc8ccae6071f607c2f3feff6f2c7d5a (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
// license:BSD-3-Clause
// copyright-holders:Antoine Mine
/**********************************************************************
Copyright (C) Antoine Mine' 2006
Motorola 6846 timer emulation.
**********************************************************************/
#ifndef MAME_MACHINE_MC6846_H
#define MAME_MACHINE_MC6846_H
#pragma once
class mc6846_device : public device_t
{
public:
mc6846_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
auto out_port() { return m_out_port_cb.bind(); }
auto in_port() { return m_in_port_cb.bind(); }
auto cp2() { return m_out_cp2_cb.bind(); }
auto cto() { return m_out_cto_cb.bind(); }
auto irq() { return m_irq_cb.bind(); }
/* interface to CPU via address/data bus*/
DECLARE_READ8_MEMBER(read);
DECLARE_WRITE8_MEMBER(write);
/* asynchronous write from outside world into interrupt-generating pins */
void set_input_cp1(int data);
void set_input_cp2(int data);
/* polling from outside world */
uint8_t get_output_port();
uint8_t get_output_cto();
uint8_t get_output_cp2();
/* partial access to internal state */
uint16_t get_preset(); /* timer interval - 1 in us */
protected:
// device-level overrides
virtual void device_start() override;
virtual void device_reset() override;
private:
// internal state
/* registers */
uint8_t m_csr; /* 0,4: combination status register */
uint8_t m_pcr; /* 1: peripheral control register */
uint8_t m_ddr; /* 2: data direction register */
uint8_t m_pdr; /* 3: peripheral data register (last cpu write) */
uint8_t m_tcr; /* 5: timer control register */
/* lines */
uint8_t m_cp1; /* 1-bit input */
uint8_t m_cp2; /* 1-bit input/output: last external write */
uint8_t m_cp2_cpu; /* last cpu write */
uint8_t m_cto; /* 1-bit timer output (unmasked) */
/* internal state */
uint8_t m_time_MSB; /* MSB buffer register */
uint8_t m_csr0_to_be_cleared;
uint8_t m_csr1_to_be_cleared;
uint8_t m_csr2_to_be_cleared;
uint16_t m_latch; /* timer latch */
uint16_t m_preset; /* preset value */
uint8_t m_timer_started;
/* timers */
emu_timer *m_interval; /* interval programmable timer */
emu_timer *m_one_shot; /* 1-us x factor one-shot timer */
/* CPU write to the outside through chip */
devcb_write8 m_out_port_cb; /* 8-bit output */
devcb_write_line m_out_cp2_cb; /* 1-bit output */
/* CPU read from the outside through chip */
devcb_read8 m_in_port_cb; /* 8-bit input */
/* asynchronous timer output to outside world */
devcb_write_line m_out_cto_cb; /* 1-bit output */
/* timer interrupt */
devcb_write_line m_irq_cb;
int m_old_cif;
int m_old_cto;
inline uint16_t counter();
inline void update_irq();
inline void update_cto();
inline void timer_launch();
TIMER_CALLBACK_MEMBER(timer_expire);
TIMER_CALLBACK_MEMBER(timer_one_shot);
};
DECLARE_DEVICE_TYPE(MC6846, mc6846_device)
#endif // MAME_MACHINE_MC6846_H
|