[ARM] How to interface 20x4 LCD display with ADuC7026?

Code C - [expand]
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
/*
RS pin = Port 3.4
R/W pin = Port 3.5
E pin = Port 3.6
 
Data 7 = Port 3.0
Data 6 = Port 3.1
Data 5 = Port 3.2
Data 4 = Port 3.3
*/
 
 
#define RSL GP3CLR=0x00100000;
#define RSH GP3SET=0x00100000;
#define RWL GP3CLR=0x00200000;
#define RWH GP3SET=0x00200000;
#define EL GP3CLR=0x00400000;
#define EH GP3SET=0x00400000;
 
 
void initlcd(){
GP3CON = 0;
GP3SET = 0x7F000000;
delay(15000);
RSL;
write(0x30);
delay(4100);
write(0x30);
delay(100);
write(0x30);
write(0x2);
write(0x38);
write(0x08);
write(0x01);
write(0x06);
}
 
void setcursor(unsigned char col, unsigned char line_addr){
unsigned char addr;
addr = line_addr+ col;
addr = 0x80 + (addr & 0x7f);
write_cmd(addr);
}
 
void lcdclr(void){
write_cmd(0x01);
setcursor(0,0);
}
 
void write(unsigned char a){
RWL;
EH;
GP3CLR = 0xFF000000;
GP3SET = (a & 0xF)<<16;
delay(10);
EL;
delay(10);
}
 
void write_cmd(unsigned char a){
chk_busy();
RSL;
write(a>>4);
write(a);
}
 
void write_data(unsigned char a){
chk_busy();
RSH;
write(a>>4);
write(a);
}