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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
// license:BSD-3-Clause
// copyright-holders:Juergen Buchmueller
/***************************************************************************
z80daisy.c
Z80/180 daisy chaining support functions.
***************************************************************************/
#include "emu.h"
#include "z80daisy.h"
//**************************************************************************
// DEVICE Z80 DAISY INTERFACE
//**************************************************************************
//-------------------------------------------------
// device_z80daisy_interface - constructor
//-------------------------------------------------
device_z80daisy_interface::device_z80daisy_interface(const machine_config &mconfig, device_t &device)
: device_interface(device, "z80daisy")
{
}
//-------------------------------------------------
// ~device_z80daisy_interface - destructor
//-------------------------------------------------
device_z80daisy_interface::~device_z80daisy_interface()
{
}
//**************************************************************************
// Z80 DAISY CHAIN
//**************************************************************************
//-------------------------------------------------
// z80_daisy_chain - constructor
//-------------------------------------------------
z80_daisy_chain::z80_daisy_chain()
: m_daisy_list(nullptr)
{
}
//-------------------------------------------------
// init - allocate the daisy chain based on the
// provided configuration
//-------------------------------------------------
void z80_daisy_chain::init(device_t *cpudevice, const z80_daisy_config *daisy)
{
// create a linked list of devices
daisy_entry **tailptr = &m_daisy_list;
for ( ; daisy->devname != nullptr; daisy++)
{
// find the device
device_t *target;
if ((target = cpudevice->subdevice(daisy->devname)) == nullptr)
{
if ((target = cpudevice->siblingdevice(daisy->devname)) == nullptr)
fatalerror("Unable to locate device '%s'\n", daisy->devname);
}
// make sure it has an interface
device_z80daisy_interface *intf;
if (!target->interface(intf))
fatalerror("Device '%s' does not implement the z80daisy interface!\n", daisy->devname);
// append to the end, or overwrite existing entry
daisy_entry *next = (*tailptr) ? (*tailptr)->m_next : nullptr;
if (*tailptr != nullptr)
auto_free(cpudevice->machine(), *tailptr);
*tailptr = auto_alloc(cpudevice->machine(), daisy_entry(target));
(*tailptr)->m_next = next;
tailptr = &(*tailptr)->m_next;
}
}
//-------------------------------------------------
// reset - send a reset signal to all chained
// devices
//-------------------------------------------------
void z80_daisy_chain::reset()
{
// loop over all devices and call their reset function
for (daisy_entry *daisy = m_daisy_list; daisy != nullptr; daisy = daisy->m_next)
daisy->m_device->reset();
}
//-------------------------------------------------
// update_irq_state - update the IRQ state and
// return assert/clear based on the state
//-------------------------------------------------
int z80_daisy_chain::update_irq_state()
{
// loop over all devices; dev[0] is highest priority
for (daisy_entry *daisy = m_daisy_list; daisy != nullptr; daisy = daisy->m_next)
{
// if this device is asserting the INT line, that's the one we want
int state = daisy->m_interface->z80daisy_irq_state();
if (state & Z80_DAISY_INT)
return ASSERT_LINE;
// if this device is asserting the IEO line, it blocks everyone else
if (state & Z80_DAISY_IEO)
return CLEAR_LINE;
}
return CLEAR_LINE;
}
//-------------------------------------------------
// call_ack_device - acknowledge an interrupt
// from a chained device and return the vector
//-------------------------------------------------
int z80_daisy_chain::call_ack_device()
{
int vector = 0;
// loop over all devices; dev[0] is the highest priority
for (daisy_entry *daisy = m_daisy_list; daisy != nullptr; daisy = daisy->m_next)
{
// if this device is asserting the INT line, that's the one we want
int state = daisy->m_interface->z80daisy_irq_state();
vector = daisy->m_interface->z80daisy_irq_ack();
if (state & Z80_DAISY_INT)
return vector;
}
//logerror("z80daisy_call_ack_device: failed to find an device to ack!\n");
return vector;
}
//-------------------------------------------------
// call_reti_device - signal a RETI operator to
// the chain
//-------------------------------------------------
void z80_daisy_chain::call_reti_device()
{
// loop over all devices; dev[0] is the highest priority
for (daisy_entry *daisy = m_daisy_list; daisy != nullptr; daisy = daisy->m_next)
{
// if this device is asserting the IEO line, that's the one we want
int state = daisy->m_interface->z80daisy_irq_state();
if (state & Z80_DAISY_IEO)
{
daisy->m_interface->z80daisy_irq_reti();
return;
}
}
//logerror("z80daisy_call_reti_device: failed to find an device to reti!\n");
}
//-------------------------------------------------
// daisy_entry - constructor
//-------------------------------------------------
z80_daisy_chain::daisy_entry::daisy_entry(device_t *device)
: m_next(nullptr),
m_device(device),
m_interface(nullptr)
{
device->interface(m_interface);
}
|