简易RAM的C++实现_c++ram

简易RAM的C++实现

本文通过C++程序设计语言实现了一个简易的RAM，具有数据读写功能。

#include <stdio.h>
#define memsize (4096)
typedef int word;
union dataunion {
	char c[sizeof(double)];
	double d;
	float f;
	long l;
	int i;
	short s;
} datarray;
char mem[memsize];
char readbyte(unsigned addr)
{
	return mem[addr];
}
word readword(unsigned addr)
{ 
	return *((word*)&(mem[addr]));
}
short readshort(unsigned addr)
{ 
	unsigned k = addr;
	for(int i=0; i<sizeof(short); i++, k++)
	datarray.c[i] = mem[k];
	return datarray.s;
}
int readint(unsigned addr)
{
	unsigned k = addr;
	for(int i=0; i<sizeof(int); i++, k++)
	datarray.c[i] = mem[k];
	return datarray.i;
}
long readlong(unsigned addr)
{
	unsigned k = addr;
	for(int i=0; i<sizeof(long); i++, k++)
	datarray.c[i] = mem[k];
	return datarray.l;
}
float readfloat(unsigned addr)
{
	unsigned k = addr;
	for(int i=0; i<sizeof(float); i++, k++)
	datarray.c[i] = mem[k];
	return datarray.f;
}
double readdouble(unsigned addr)
{
	unsigned k = addr;
	for(int i=0; i<sizeof(double); i++, k++)
	datarray.c[i] = mem[k];
	return datarray.d;
}
void writeword(unsigned addr,word data)
{
	*((word*)&mem[addr])=data;
}
int main()
{
	for(int i=0; i<memsize; i+=sizeof(word))
	writeword(i,i); 
	for(int i=0; i<memsize; i+=sizeof(int))
	printf("mem[%d] = %d\n", i, readint(i));
	for(int i=0; i<memsize; i++)
	printf("mem[%d] = %d\n", i, readbyte(i));
	return 0;
}
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