| 4 |
4 |
#include "graph.h"
|
| 5 |
5 |
#include "sprite.h"
|
| 6 |
6 |
|
| 7 |
|
#include "i8254.h"
|
|
7 |
#define TIMER_FREQ 1193182 /**< @brief clock frequency for timer in PC and AT */
|
|
8 |
#define TIMER_MIN_FREQ (TIMER_FREQ/UINT16_MAX) + ((TIMER_FREQ % UINT16_MAX) ? 1 : 0) /**< @brief mininum frequency for timer */
|
| 8 |
9 |
|
|
10 |
/* I/O port addresses */
|
|
11 |
|
|
12 |
#define TIMER_0 0x40 /**< @brief Timer 0 count register */
|
|
13 |
#define TIMER_1 0x41 /**< @brief Timer 1 count register */
|
|
14 |
#define TIMER_2 0x42 /**< @brief Timer 2 count register */
|
|
15 |
#define TIMER_CTRL 0x43 /**< @brief Control register */
|
|
16 |
|
|
17 |
#define SPEAKER_CTRL 0x61 /**< @brief Register for speaker control */
|
|
18 |
|
|
19 |
/* Timer control */
|
|
20 |
|
|
21 |
/* Timer selection: bits 7 and 6 */
|
|
22 |
|
|
23 |
#define TIMER_SEL0 0x00 /**< @brief Control Word for Timer 0 */
|
|
24 |
#define TIMER_SEL1 BIT(6) /**< @brief Control Word for Timer 1 */
|
|
25 |
#define TIMER_SEL2 BIT(7) /**< @brief Control Word for Timer 2 */
|
|
26 |
#define TIMER_RB_CMD (BIT(7) | BIT(6)) /**< @brief Read Back Command */
|
|
27 |
|
|
28 |
/* Register selection: bits 5 and 4 */
|
|
29 |
|
|
30 |
#define TIMER_LSB BIT(4) /**< @brief Initialize Counter LSB only */
|
|
31 |
#define TIMER_MSB BIT(5) /**< @brief Initialize Counter MSB only */
|
|
32 |
#define TIMER_LSB_MSB (TIMER_LSB | TIMER_MSB) /**< @brief Initialize LSB first and MSB afterwards */
|
|
33 |
#define TIMER_INMODE_MASK 0x30 /**< @brief Mask for Timer Counter Mode */
|
|
34 |
#define TIMER_INMODE_POS 4 /**< @brief Bit position of Timer Counter Mode */
|
|
35 |
|
|
36 |
/* Operating mode: bits 3, 2 and 1 */
|
|
37 |
|
|
38 |
#define TIMER_SQR_WAVE (BIT(2) | BIT(1)) /**< @brief Mode 3: square wave generator */
|
|
39 |
#define TIMER_RATE_GEN BIT(2) /**< @brief Mode 2: rate generator */
|
|
40 |
#define TIMER_MODE_MASK 0x0E /**< @brief Mask for mode */
|
|
41 |
#define TIMER_MODE_POS 1 /**< @brief Position of smallest bit from mode */
|
|
42 |
#define TIMER_MODE_2ALT 0x6 /**< @brief Alternative notation for mode 2 */
|
|
43 |
#define TIMER_MODE_3ALT 0x7 /**< @brief Alternative notation for mode 3 */
|
|
44 |
#define TIMER_MODE_RED2 0x03 /**< @brief Reduce 3-bit mode to 2-bit mode */
|
|
45 |
|
|
46 |
/* Counting mode: bit 0 */
|
|
47 |
|
|
48 |
#define TIMER_BCD 0x01 /**< @brief Count in BCD */
|
|
49 |
#define TIMER_BIN 0x00 /**< @brief Count in binary */
|
|
50 |
|
|
51 |
/* READ-BACK COMMAND FORMAT */
|
|
52 |
|
|
53 |
#define TIMER_RB_COUNT_ BIT(5) /**< @brief Read counter value on read-back (0 to activate) */
|
|
54 |
#define TIMER_RB_STATUS_ BIT(4) /**< @brief Read status value on read-back (0 to activate) */
|
|
55 |
#define TIMER_RB_SEL(n) BIT((n) + 1) /**< @brief Select timer to read information from */
|
|
56 |
|
| 9 |
57 |
int (subscribe_timer_interrupt)(uint8_t interrupt_bit, int *interrupt_id) {
|
| 10 |
58 |
if (interrupt_id == NULL) return 1;
|
| 11 |
59 |
*interrupt_id = interrupt_bit;
|