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
|
#pragma once
enum uart_16550_offset {
Data = 0, // read from receive buffer / write to transmit buffer | BaudDiv_l
InterruptControl = 1, // interrupt enable | BaudDiv_h
FifoControl = 2, // interrupt ID and FIFO control
LineControl = 3, // most significant bit is the DLAB
ModemControl = 4,
LineStatus = 5,
ModemStatus = 6,
Scratch = 7,
};
// Line Control
// | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
// |dla| | parity | s | data |
enum LineControl {
d5bit = 0b00000000, // data bits
d6bit = 0b00000001,
d7bit = 0b00000010,
d8bit = 0b00000011,
// none = 0b00000000, // parity bits
odd = 0b00001000,
even = 0b00011000,
mark = 0b00101000,
space = 0b00111000,
// s1bit = 0b00000000, // stop bits
s2bit = 0b00000100, // 1.5 for 5bit data; 2 otherwise
dlab = 0b10000000, // divisor latch access bit
};
// Line Status Register
enum LineStatus {
DR = 0b00000001, // data ready: see if there is data to read
OE = 0b00000010, // overrun error: see if there has been data lost
PE = 0b00000100, // parity error: see if there was error in transmission
FE = 0b00001000, // framing error: see if a stop bit was missing
BI = 0b00010000, // break indicator: see if there is a break in data input
THRE = 0b00100000, // transmitter holding register empty: see if transmission buffer is empty
TEMT = 0b01000000, // transmitter empty: see if transmitter is not doing anything
ERRO = 0b10000000, // impending error: see if there is an error with a word in the input buffer
};
enum UART {
COM1 = 0x3f8,
COM2 = 0x2f8,
COM3 = 0x3E8,
COM4 = 0x2E8,
COM5 = 0x5F8,
COM6 = 0x4F8,
COM7 = 0x5E8,
COM8 = 0x4E8,
};
int uart_init(enum UART port);
int uart_puts(enum UART port, const char *string, int length);
|
