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#ifndef _LCOM_I8254_H_
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#define _LCOM_I8254_H_
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#include <lcom/lcf.h> |
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/** @defgroup i8254 i8254
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*
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* Constants for programming the i8254 Timer. Needs to be completed.
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*/
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#define TIMER_FREQ 1193182 /**< @brief clock frequency for timer in PC and AT */ |
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#define TIMER_MIN_FREQ (TIMER_FREQ/UINT16_MAX) + ((TIMER_FREQ % UINT16_MAX) ? 1 : 0) /**< @brief mininum frequency for timer */ |
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#define TIMER0_IRQ 0 /**< @brief Timer 0 IRQ line */ |
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/* I/O port addresses */
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#define TIMER_0 0x40 /**< @brief Timer 0 count register */ |
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#define TIMER_1 0x41 /**< @brief Timer 1 count register */ |
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#define TIMER_2 0x42 /**< @brief Timer 2 count register */ |
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#define TIMER_CTRL 0x43 /**< @brief Control register */ |
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#define SPEAKER_CTRL 0x61 /**< @brief Register for speaker control */ |
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/* Timer control */
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/* Timer selection: bits 7 and 6 */
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#define TIMER_SEL0 0x00 /**< @brief Control Word for Timer 0 */ |
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#define TIMER_SEL1 BIT(6) /**< @brief Control Word for Timer 1 */ |
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#define TIMER_SEL2 BIT(7) /**< @brief Control Word for Timer 2 */ |
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#define TIMER_RB_CMD (BIT(7) | BIT(6)) /**< @brief Read Back Command */ |
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/* Register selection: bits 5 and 4 */
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#define TIMER_LSB BIT(4) /**< @brief Initialize Counter LSB only */ |
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#define TIMER_MSB BIT(5) /**< @brief Initialize Counter MSB only */ |
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#define TIMER_LSB_MSB (TIMER_LSB | TIMER_MSB) /**< @brief Initialize LSB first and MSB afterwards */ |
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#define TIMER_INMODE_MASK 0x30 /**< @brief Mask for Timer Counter Mode */ |
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#define TIMER_INMODE_POS 4 /**< @brief Bit position of Timer Counter Mode */ |
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/* Operating mode: bits 3, 2 and 1 */
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#define TIMER_SQR_WAVE (BIT(2) | BIT(1)) /**< @brief Mode 3: square wave generator */ |
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#define TIMER_RATE_GEN BIT(2) /**< @brief Mode 2: rate generator */ |
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#define TIMER_MODE_MASK 0x0E /**< @brief Mask for mode */ |
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#define TIMER_MODE_POS 1 /**< @brief Position of smallest bit from mode */ |
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#define TIMER_MODE_2ALT 0x6 /**< @brief Alternative notation for mode 2 */ |
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#define TIMER_MODE_3ALT 0x7 /**< @brief Alternative notation for mode 3 */ |
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#define TIMER_MODE_RED2 0x03 /**< @brief Reduce 3-bit mode to 2-bit mode */ |
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/* Counting mode: bit 0 */
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#define TIMER_BCD 0x01 /**< @brief Count in BCD */ |
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#define TIMER_BIN 0x00 /**< @brief Count in binary */ |
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/* READ-BACK COMMAND FORMAT */
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#define TIMER_RB_COUNT_ BIT(5) /**< @brief Read counter value on read-back (0 to activate) */ |
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#define TIMER_RB_STATUS_ BIT(4) /**< @brief Read status value on read-back (0 to activate) */ |
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#define TIMER_RB_SEL(n) BIT((n) + 1) /**< @brief Select timer to read information from */ |
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/**@}*/
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#endif /* _LCOM_I8254_H */ |