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root / proj / libs / timer / src / timer.c @ 293

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#include <lcom/lcf.h>
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#include "timer.h"
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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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/* 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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int (subscribe_timer_interrupt)(uint8_t interrupt_bit, int *interrupt_id) {
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    if (interrupt_id == NULL) return 1;
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    *interrupt_id = interrupt_bit;
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    return (sys_irqsetpolicy(TIMER0_IRQ, IRQ_REENABLE, interrupt_id));
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}
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uint32_t no_interrupts = 0;
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void (timer_int_handler)() {
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    no_interrupts++;
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}