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
|
// license:BSD-3-Clause
// copyright-holders:Fabio Priuli
/***********************************************************************************************************
Generic RAM socket emulation
This offers generic access to RAM
generic_ram_plain : returns 0xff when the system reads beyond the end of the RAM
generic_ram_linear : maps linearly the RAM in the accessed area (i.e., read/write offset is masked with
(RAM size - 1) )
TODO:
- support variable RAM size
- possibly support linear mapping when non-power of 2 RAMs are mapped
- add support for 16bit & 32bit RAM access
***********************************************************************************************************/
#include "emu.h"
#include "ram.h"
//-------------------------------------------------
// constructor
//-------------------------------------------------
const device_type GENERIC_RAM_32K_PLAIN = &device_creator<generic_ram_32k_plain_device>;
const device_type GENERIC_RAM_64K_PLAIN = &device_creator<generic_ram_64k_plain_device>;
const device_type GENERIC_RAM_128K_PLAIN = &device_creator<generic_ram_128k_plain_device>;
const device_type GENERIC_RAM_32K_LINEAR = &device_creator<generic_ram_32k_linear_device>;
const device_type GENERIC_RAM_64K_LINEAR = &device_creator<generic_ram_64k_linear_device>;
const device_type GENERIC_RAM_128K_LINEAR = &device_creator<generic_ram_128k_linear_device>;
generic_ram_plain_device::generic_ram_plain_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, UINT32 size, const char *shortname, const char *source)
: device_t(mconfig, type, name, tag, owner, clock, shortname, source),
device_generic_cart_interface(mconfig, *this),
m_size(size)
{
}
generic_ram_linear_device::generic_ram_linear_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, UINT32 size, const char *shortname, const char *source)
: device_t(mconfig, type, name, tag, owner, clock, shortname, source),
device_generic_cart_interface(mconfig, *this),
m_size(size)
{
}
generic_ram_32k_plain_device::generic_ram_32k_plain_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: generic_ram_plain_device(mconfig, GENERIC_RAM_32K_PLAIN, "Generic RAM 32K (plain mapping)", tag, owner, clock, 0x8000, "generic_ram32p", __FILE__)
{
}
generic_ram_64k_plain_device::generic_ram_64k_plain_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: generic_ram_plain_device(mconfig, GENERIC_RAM_64K_PLAIN, "Generic RAM 64K (plain mapping)", tag, owner, clock, 0x10000, "generic_ram64p", __FILE__)
{
}
generic_ram_128k_plain_device::generic_ram_128k_plain_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: generic_ram_plain_device(mconfig, GENERIC_RAM_128K_PLAIN, "Generic RAM 128K (plain mapping)", tag, owner, clock, 0x20000, "generic_ram128p", __FILE__)
{
}
generic_ram_32k_linear_device::generic_ram_32k_linear_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: generic_ram_linear_device(mconfig, GENERIC_RAM_32K_LINEAR, "Generic RAM 32K (linear mapping)", tag, owner, clock, 0x8000, "generic_ram32l", __FILE__)
{
}
generic_ram_64k_linear_device::generic_ram_64k_linear_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: generic_ram_linear_device(mconfig, GENERIC_RAM_64K_LINEAR, "Generic RAM 64K (linear mapping)", tag, owner, clock, 0x10000, "generic_ram64l", __FILE__)
{
}
generic_ram_128k_linear_device::generic_ram_128k_linear_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: generic_ram_linear_device(mconfig, GENERIC_RAM_128K_LINEAR, "Generic RAM 128K (linear mapping)", tag, owner, clock, 0x20000, "generic_ram128l", __FILE__)
{
}
void generic_ram_plain_device::device_start()
{
m_ram.resize(m_size);
save_item(NAME(m_ram));
}
void generic_ram_linear_device::device_start()
{
m_ram.resize(m_size);
save_item(NAME(m_ram));
}
/*-------------------------------------------------
mapper specific handlers
-------------------------------------------------*/
READ8_MEMBER(generic_ram_plain_device::read_ram)
{
if (offset < m_ram.size())
return m_ram[offset];
else
return 0xff;
}
WRITE8_MEMBER(generic_ram_plain_device::write_ram)
{
if (offset < m_ram.size())
m_ram[offset] = data;
}
READ8_MEMBER(generic_ram_linear_device::read_ram)
{
return m_ram[offset % m_ram.size()];
}
WRITE8_MEMBER(generic_ram_linear_device::write_ram)
{
m_ram[offset % m_ram.size()] = data;
}
|