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
|
namespace Q1Emu.Chip;
using System;
using System.Collections.Generic;
public partial class Q1Cpu
{
public u16 FetchData(u8 mode)
{
return mode switch
{
0x0 => this.AddressingMode_Implicit(),
0x1 => this.AddressingMode_Immediate(),
0x2 => this.AddressingMode_Direct(),
0x3 => this.AddressingMode_Indirect(),
0x4 => this.AddressingMode_Relative(),
0x5 => this.AddressingMode_Register(),
0x6 => this.AddressingMode_RegisterIndirect(),
0x7 => this.AddressingMode_RegisterIndirectOffset(),
_ => throw new InvalidOperationException($"Unknown addressing mode: {mode:X2}"),
};
}
public void StoreData(u8 mode, u16 value)
{
Console.WriteLine($"StoreData: mode={mode:X8}, value={value:X16}");
if (mode != 0x05)
{
u16 address = this.FetchData(mode);
Console.WriteLine($"StoreData: address={address:X16}");
this.Bus.WriteWord(address, value);
}
else
{
u8 regIndex = this.Bus.Read(this.PC);
this.PC += 1;
this.StoreRegister(regIndex, value);
}
}
public void TransformData(u8 mode, Func<u16, u16> transform)
{
if (mode != 0x05)
{
u16 address = this.FetchData(mode);
u16 value = this.Bus.ReadWord(address);
u16 transformedValue = transform(value);
this.Bus.WriteWord(address, transformedValue);
}
else
{
u8 regIndex = this.Bus.Read(this.PC);
this.PC += 1;
u16 value = this.FetchRegister(regIndex);
u16 transformedValue = transform(value);
this.StoreRegister(regIndex, transformedValue);
}
}
public u8 AddressingModeLength(u8 mode)
{
return mode switch
{
0x0 => 0, // Implicit
0x1 => 2, // Immediate
0x2 => 2, // Direct
0x3 => 2, // Indirect
0x4 => 2, // Relative
0x5 => 1, // Register
0x6 => 1, // Register indirect
0x7 => 3, // Register indirect with offset
_ => throw new InvalidOperationException($"Unknown addressing mode: {mode:X2}"),
};
}
public u16 AddressingMode_Implicit()
{
return 0;
}
public u16 AddressingMode_Immediate()
{
u16 value = this.Bus.ReadWord(this.PC);
this.PC += 2;
return value;
}
public u16 AddressingMode_Direct()
{
u16 address = this.Bus.ReadWord(this.PC);
this.PC += 2;
u16 value = this.Bus.ReadWord(address);
return value;
}
public u16 AddressingMode_Indirect()
{
u16 address = this.Bus.ReadWord(this.PC);
this.PC += 2;
u16 indirectAddress = this.Bus.ReadWord(address);
u16 value = this.Bus.ReadWord(indirectAddress);
return value;
}
public u16 AddressingMode_Relative()
{
u16 offset = this.Bus.ReadWord(this.PC);
this.PC += 2;
u16 address = (u16) (this.PC + offset);
return address;
}
public u16 AddressingMode_Register()
{
u8 regIndex = this.Bus.Read(this.PC);
this.PC += 1;
return this.FetchRegister(regIndex);
}
public u16 AddressingMode_RegisterIndirect()
{
u8 regIndex = this.Bus.Read(this.PC);
this.PC += 1;
u16 address = this.FetchRegister(regIndex);
u16 value = this.Bus.ReadWord(address);
return value;
}
public u16 AddressingMode_RegisterIndirectOffset()
{
u8 regIndex = this.Bus.Read(this.PC);
this.PC += 1;
u16 offset = this.Bus.ReadWord(this.PC);
this.PC += 2;
u16 address = (u16) (this.FetchRegister(regIndex) + offset);
u16 value = this.Bus.ReadWord(address);
return value;
}
}
|
