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
|
#ifndef H__USART_
#define H__USART_
#include "common.h"
#include "rcc.h"
#include <stdint.h>
/*
* Possibel USART clock sources.
*/
typedef enum {
USART_CLK_SRC_PLK = 0, /* Clock derived from the SysClk. */
USART_CLK_SRC_SYSCLK = 1, /* System clock. */
USART_CLK_SRC_HSI16 = 2, /* 16MHz oscillator. */
USART_CLK_SRC_LSE = 3 /* Low power 32kHz clock. */
} usart_clk_src_t;
typedef struct {
/* USART configuration registers 0x04 - 0x0c. */
uint32_t c_r1;
uint32_t c_r2;
uint32_t c_r3;
/* USART baud rate register. */
uint32_t br_r;
uint32_t gtp_r;
uint32_t rto_r;
uint32_t rq_r;
uint32_t is_r;
uint32_t ic_r;
uint32_t rd_r;
uint32_t td_r;
} usart_t;
#define USART1 (* (__IO usart_t*) 0x40013800)
#define USART2 (* (__IO usart_t*) 0x40004400)
typedef enum {
OVERSAMPLE_8,
OVERSAMPLE_16
} oversampling_mode_t;
static inline void usart_set_divisor(
__IO usart_t* usart,
uint32_t usartdiv)
{
if (usart->c_r1 & (1 << 15)) {
/* OVER8 is set. */
usart->br_r =
(usartdiv & ~7) |
((usartdiv & 7) >> 1);
} else {
/* OVER8 is not set. */
usart->br_r = usartdiv;
}
}
static inline void usart_set_oversampling_mode(
__IO usart_t* usart,
oversampling_mode_t mode)
{
if (mode == OVERSAMPLE_8) {
usart->c_r1 |= 1 << 15;
} else {
usart->c_r1 &= ~(1 << 15);
}
}
typedef enum {
USART_PARITY_DISABLED = 0,
USART_PARITY_EVEN = 2 << 9,
USART_PARITY_ODD = 3 << 9,
} usart_parity_t;
typedef enum {
USART_ENABLE_TX_RX = 0x0d, /* 0b1101 */
USART_ENABLE_TX = 0x09, /* 0b1001 */
USART_ENABLE_RX = 0x05, /* 0b0101 */
USART_ENABLE_DISABLED = 0x00, /* 0b0000 */
} usart_enable_t;
void usart_set_parity(__IO usart_t* usart, usart_parity_t parity);
void usart_set_enabled(__IO usart_t* usart, usart_enable_t enabled);
/*
* Send a byte on the usart, This command blocks until the data
* is fully sent.
*/
void usart_transmit_byte(__IO usart_t* usart, uint8_t byte);
void set_usart1_clock_src(__IO rcc_t* rcc, usart_clk_src_t usart_clk_src);
void set_usart1_clock_enabled(__IO rcc_t* rcc, bool enable);
void set_usart2_clock_src(__IO rcc_t* rcc, usart_clk_src_t usart_clk_src);
void set_usart2_clock_enabled(__IO rcc_t* rcc, bool enable);
#endif /* H__USART_ */
|
