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1 | 4 | up20180655 | #ifndef _LCOM_I8254_H_
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2 | #define _LCOM_I8254_H_
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3 | |||
4 | #include <lcom/lcf.h> |
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5 | |||
6 | /** @defgroup i8254 i8254
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7 | * @{
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8 | *
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9 | * Constants for programming the i8254 Timer. Needs to be completed.
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10 | */
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11 | |||
12 | 20 | up20180655 | #define TIMER_FREQ 1193182 /**< @brief clock frequency for timer in PC and AT */ |
13 | 27 | up20180655 | #define TIMER_MIN_FREQ (TIMER_FREQ/UINT16_MAX) + ((TIMER_FREQ % UINT16_MAX) ? 1 : 0) /**< @brief mininum frequency for timer */ |
14 | 20 | up20180655 | #define TIMER0_IRQ 0 /**< @brief Timer 0 IRQ line */ |
15 | 4 | up20180655 | |
16 | /* I/O port addresses */
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17 | |||
18 | #define TIMER_0 0x40 /**< @brief Timer 0 count register */ |
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19 | #define TIMER_1 0x41 /**< @brief Timer 1 count register */ |
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20 | #define TIMER_2 0x42 /**< @brief Timer 2 count register */ |
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21 | #define TIMER_CTRL 0x43 /**< @brief Control register */ |
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22 | |||
23 | #define SPEAKER_CTRL 0x61 /**< @brief Register for speaker control */ |
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24 | |||
25 | /* Timer control */
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26 | |||
27 | /* Timer selection: bits 7 and 6 */
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28 | |||
29 | #define TIMER_SEL0 0x00 /**< @brief Control Word for Timer 0 */ |
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30 | #define TIMER_SEL1 BIT(6) /**< @brief Control Word for Timer 1 */ |
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31 | #define TIMER_SEL2 BIT(7) /**< @brief Control Word for Timer 2 */ |
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32 | #define TIMER_RB_CMD (BIT(7) | BIT(6)) /**< @brief Read Back Command */ |
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33 | |||
34 | /* Register selection: bits 5 and 4 */
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35 | |||
36 | #define TIMER_LSB BIT(4) /**< @brief Initialize Counter LSB only */ |
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37 | #define TIMER_MSB BIT(5) /**< @brief Initialize Counter MSB only */ |
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38 | #define TIMER_LSB_MSB (TIMER_LSB | TIMER_MSB) /**< @brief Initialize LSB first and MSB afterwards */ |
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39 | 10 | up20180655 | #define TIMER_INMODE_MASK 0x30 //0011 0000 |
40 | 6 | up20180642 | #define TIMER_INMODE_POS 4 |
41 | 4 | up20180655 | |
42 | /* Operating mode: bits 3, 2 and 1 */
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43 | |||
44 | #define TIMER_SQR_WAVE (BIT(2) | BIT(1)) /**< @brief Mode 3: square wave generator */ |
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45 | #define TIMER_RATE_GEN BIT(2) /**< @brief Mode 2: rate generator */ |
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46 | 10 | up20180655 | #define TIMER_MODE_MASK 0x0E /**< @brief Mask for mode */ |
47 | 6 | up20180642 | #define TIMER_MODE_POS 1 /**< @brief Position of smallest bit from mode */ |
48 | 17 | up20180642 | #define TIMER_MODE_2ALT 0x6 /**< @brief Alternative notation for mode 2 */ |
49 | #define TIMER_MODE_3ALT 0x7 /**< @brief Alternative notation for mode 3 */ |
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50 | 16 | up20180642 | #define TIMER_MODE_RED2 0x03 /**< @brief Reduce 3-bit mode to 2-bit mode */ |
51 | 4 | up20180655 | |
52 | /* Counting mode: bit 0 */
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53 | |||
54 | #define TIMER_BCD 0x01 /**< @brief Count in BCD */ |
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55 | #define TIMER_BIN 0x00 /**< @brief Count in binary */ |
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56 | |||
57 | /* READ-BACK COMMAND FORMAT */
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58 | |||
59 | #define TIMER_RB_COUNT_ BIT(5) |
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60 | #define TIMER_RB_STATUS_ BIT(4) |
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61 | #define TIMER_RB_SEL(n) BIT((n) + 1) |
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62 | |||
63 | /**@}*/
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64 | |||
65 | #endif /* _LCOM_I8254_H */ |