Project

General

Profile

Statistics
| Revision:

root / proj / include / i8254.h @ 176

History | View | Annotate | Download (2.89 KB)

1
#ifndef _LCOM_I8254_H_
2
#define _LCOM_I8254_H_
3

    
4
#include <lcom/lcf.h>
5

    
6
/** @defgroup i8254 i8254
7
 *
8
 * Constants for programming the i8254 Timer. Needs to be completed.
9
 */
10

    
11
#define TIMER_FREQ     1193182                                                          /**< @brief clock frequency for timer in PC and AT */
12
#define TIMER_MIN_FREQ (TIMER_FREQ/UINT16_MAX) + ((TIMER_FREQ % UINT16_MAX) ? 1 : 0)    /**< @brief mininum frequency for timer */
13
#define TIMER0_IRQ     0                                                                /**< @brief Timer 0 IRQ line */
14

    
15
/* I/O port addresses */
16

    
17
#define TIMER_0    0x40         /**< @brief Timer 0 count register */
18
#define TIMER_1    0x41         /**< @brief Timer 1 count register */
19
#define TIMER_2    0x42         /**< @brief Timer 2 count register */
20
#define TIMER_CTRL 0x43         /**< @brief Control register */
21

    
22
#define SPEAKER_CTRL 0x61       /**< @brief Register for speaker control  */
23

    
24
/* Timer control */
25

    
26
/* Timer selection: bits 7 and 6 */
27

    
28
#define TIMER_SEL0   0x00              /**< @brief Control Word for Timer 0 */
29
#define TIMER_SEL1   BIT(6)            /**< @brief Control Word for Timer 1 */
30
#define TIMER_SEL2   BIT(7)            /**< @brief Control Word for Timer 2 */
31
#define TIMER_RB_CMD (BIT(7) | BIT(6)) /**< @brief Read Back Command */
32

    
33
/* Register selection: bits 5 and 4 */
34

    
35
#define TIMER_LSB     BIT(4)                    /**< @brief Initialize Counter LSB only */
36
#define TIMER_MSB     BIT(5)                    /**< @brief Initialize Counter MSB only */
37
#define TIMER_LSB_MSB (TIMER_LSB | TIMER_MSB)   /**< @brief Initialize LSB first and MSB afterwards */
38
#define TIMER_INMODE_MASK 0x30                  /**< @brief Mask for Timer Counter Mode */
39
#define TIMER_INMODE_POS  4                     /**< @brief Bit position of Timer Counter Mode */
40

    
41
/* Operating mode: bits 3, 2 and 1 */
42

    
43
#define TIMER_SQR_WAVE (BIT(2) | BIT(1)) /**< @brief Mode 3: square wave generator */
44
#define TIMER_RATE_GEN BIT(2)            /**< @brief Mode 2: rate generator */
45
#define TIMER_MODE_MASK 0x0E             /**< @brief Mask for mode */
46
#define TIMER_MODE_POS  1                /**< @brief Position of smallest bit from mode */
47
#define TIMER_MODE_2ALT 0x6              /**< @brief Alternative notation for mode 2 */
48
#define TIMER_MODE_3ALT 0x7              /**< @brief Alternative notation for mode 3 */
49
#define TIMER_MODE_RED2 0x03             /**< @brief Reduce 3-bit mode to 2-bit mode */
50

    
51
/* Counting mode: bit 0 */
52

    
53
#define TIMER_BCD 0x01 /**< @brief Count in BCD */
54
#define TIMER_BIN 0x00 /**< @brief Count in binary */
55

    
56
/* READ-BACK COMMAND FORMAT */
57

    
58
#define TIMER_RB_COUNT_  BIT(5)         /**< @brief Read counter value on read-back (0 to activate) */
59
#define TIMER_RB_STATUS_ BIT(4)         /**< @brief Read status value on read-back (0 to activate) */
60
#define TIMER_RB_SEL(n)  BIT((n) + 1)   /**< @brief Select timer to read information from */
61

    
62
/**@}*/
63

    
64
#endif /* _LCOM_I8254_H */