root / lab2 / i8254.h
History | View | Annotate | Download (1.89 KB)
1 |
#ifndef _LCOM_I8254_H_
|
---|---|
2 |
#define _LCOM_I8254_H_
|
3 |
|
4 |
#include <lcom/lcf.h> |
5 |
|
6 |
/** @defgroup i8254 i8254
|
7 |
* @{
|
8 |
*
|
9 |
* Constants for programming the i8254 Timer. Needs to be completed.
|
10 |
*/
|
11 |
|
12 |
|
13 |
|
14 |
/*IRQ's*/
|
15 |
|
16 |
#define IRQ_TIMER 0 |
17 |
#define DEFAULT_FREQ 60 |
18 |
|
19 |
|
20 |
#define TIMER_FREQ 1193182 /**< @brief clock frequency for timer in PC and AT */ |
21 |
#define MIN_FREQ 19 |
22 |
#define TIMER0_IRQ 0 /**< @brief Timer 0 IRQ line */ |
23 |
|
24 |
/* I/O port addresses */
|
25 |
|
26 |
#define TIMER_0 0x40 /**< @brief Timer 0 count register */ |
27 |
#define TIMER_1 0x41 /**< @brief Timer 1 count register */ |
28 |
#define TIMER_2 0x42 /**< @brief Timer 2 count register */ |
29 |
#define TIMER_CTRL 0x43 /**< @brief Control register */ |
30 |
|
31 |
#define SPEAKER_CTRL 0x61 /**< @brief Register for speaker control */ |
32 |
|
33 |
/* Timer control */
|
34 |
|
35 |
/* Timer selection: bits 7 and 6 */
|
36 |
|
37 |
#define TIMER_SEL0 0x00 /**< @brief Control Word for Timer 0 */ |
38 |
#define TIMER_SEL1 BIT(6) /**< @brief Control Word for Timer 1 */ |
39 |
#define TIMER_SEL2 BIT(7) /**< @brief Control Word for Timer 2 */ |
40 |
#define TIMER_RB_CMD (BIT(7) | BIT(6)) /**< @brief Read Back Command */ |
41 |
|
42 |
/* Register selection: bits 5 and 4 */
|
43 |
|
44 |
#define TIMER_LSB BIT(4) /**< @brief Initialize Counter LSB only */ |
45 |
#define TIMER_MSB BIT(5) /**< @brief Initialize Counter MSB only */ |
46 |
#define TIMER_LSB_MSB (TIMER_LSB | TIMER_MSB) /**< @brief Initialize LSB first and MSB afterwards */ |
47 |
|
48 |
/* Operating mode: bits 3, 2 and 1 */
|
49 |
|
50 |
#define TIMER_SQR_WAVE (BIT(2) | BIT(1)) /**< @brief Mode 3: square wave generator */ |
51 |
#define TIMER_RATE_GEN BIT(2) /**< @brief Mode 2: rate generator */ |
52 |
|
53 |
/* Counting mode: bit 0 */
|
54 |
|
55 |
#define TIMER_BCD 0x01 /**< @brief Count in BCD */ |
56 |
#define TIMER_BIN 0x00 /**< @brief Count in binary */ |
57 |
|
58 |
/* READ-BACK COMMAND FORMAT */
|
59 |
|
60 |
#define TIMER_RB_COUNT_ BIT(5) |
61 |
#define TIMER_RB_STATUS_ BIT(4) |
62 |
#define TIMER_RB_SEL(n) BIT((n) + 1) |
63 |
|
64 |
/**@}*/
|
65 |
|
66 |
#endif /* _LCOM_I8254_H */ |