root / lab2 / timer.h @ 9
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#ifndef __TIMER_H
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#define __TIMER_H
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/**
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* @brief Enumerated type for specifying the timer value initialization
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*/
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enum timer_init {
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INVAL_val, /*!< Invalid initialization mode */
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LSB_only, /*!< Initialization only of the LSB */
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MSB_only, /*!< Initialization only of the MSB */
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MSB_after_LSB /*!< Initialization of LSB and MSB, in this order */
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}; |
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/**
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* @brief Enumerated type for identifying the timer status fields
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*/
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enum timer_status_field {
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tsf_all, /*!< configuration/status */
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tsf_initial, /*!< timer initialization mode */
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tsf_mode, /*!< timer counting mode */
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tsf_base /*!< timer counting base */
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}; |
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/**
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* @brief Union for storing values of timer status fields, including the full status byte
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*/
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union timer_status_field_val {
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uint8_t byte; /*!< status */
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enum timer_init in_mode; /*!< initialization mode */ |
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uint8_t count_mode; /*!< counting mode: 0, 1,.., 5 */
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bool bcd; /*!< counting base, true if BCD */ |
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}; |
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/**
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* @brief Changes the operating frequency of a timer
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*
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* Must use the read-back command so that it does not change
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* the 4 LSBs (mode and BCD/binary) of the timer's control word.
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*
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* @param timer Timer to configure. (Ranges from 0 to 2)
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* @param freq Timer operating frequency
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* @return Return 0 upon success and non-zero otherwise
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*/
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int(timer_set_frequency)(uint8_t timer, uint32_t freq);
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/**
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* @brief Subscribes and enables Timer 0 interrupts
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*
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* @param bit_no address of memory to be initialized with the
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* bit number to be set in the mask returned upon an interrupt
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* @return Return 0 upon success and non-zero otherwise
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*/
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int(timer_subscribe_int)(uint8_t *bit_no);
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/**
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* @brief Unsubscribes Timer 0 interrupts
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*
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* @return Return 0 upon success and non-zero otherwise
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*/
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int(timer_unsubscribe_int)();
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/**
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* @brief Timer 0 interrupt handler
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*
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* Increments counter
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*/
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void(timer_int_handler)();
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/**
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* @brief Reads the input timer configuration (status) via read-back command
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*
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* @param timer Timer whose configuration to read (Ranges from 0 to 2)
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* @param st Address of memory position to be filled with the timer config
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* @return Return 0 upon success and non-zero otherwise
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*/
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int(timer_get_conf)(uint8_t timer, uint8_t *st);
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/**
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* @brief Shows timer configuration
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*
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#include <stdbool.h>
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#include <stdint.h>
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/** @defgroup timer timer
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* @{
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*
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* Functions for using the i8254 timers
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*/
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/** Displays, in a human friendly way, the specified field of a
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* timer status, which was read via the read-back command
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*
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* @param timer timer whose configuration should be displayed (Ranges from 0 to 2)
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* @param st status read via the read-back command
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* @param field status field to display in human friendly way
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* @return Return 0 upon success and non-zero otherwise
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*/
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int(timer_display_conf)(uint8_t timer, uint8_t st, enum timer_status_field field); |
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/**
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* @brief Prints a timer config field value
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*
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* @return Returns 0 upon success and non-zero otherwise
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*/
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int(timer_print_config)(uint8_t timer, enum timer_status_field field, |
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union timer_status_field_val val);
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/**
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* @brief Increments elapsed time count
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*
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* @return Returns the current time count
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*/
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uint32_t(timer_print_elapsed_time)(); |
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#endif /* __TIMER_H */ |