File content as of revision 5:bb04c4a3b5ba:

/*
 * mbed Library / Frequency Counter with GPS 1PPS Compensation
 *      Frequency Counter Hardware relataed program
 *      Only for ST Nucleo-F746ZG
 *
 * Copyright (c) 2014,'15,'16 Kenji Arai / JH1PJL
 *  http://www.page.sannet.ne.jp/kenjia/index.html
 *  http://mbed.org/users/kenjiArai/
 *      Started:    October   18th, 2014
 *      Revised:    January    1st, 2015
 *      Re-started: June      25th, 2016    ported from F411 board
 *      Revised:    Novemeber 23rd, 2016
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef         MBED_FRQ_CUNTR
#define         MBED_FRQ_CUNTR

#include "mbed.h"

#define DEBUG   0  // use Communication with PC(UART)

typedef union
{
    struct {
        uint64_t    f_1sec_dt;
    };
    struct {
        uint32_t    freq_dt;
        uint16_t    f_sw_dt;
        uint16_t    t_cnt;
    };
} freq_one;

namespace Frequency_counter
{

/** Frequency Counter program
 *  Only for ST Nucleo-F746ZG Board
 *
 * @code
 * #include "mbed.h"
 * #include "frq_cuntr_f746.h"
 *
 * using namespace Frequency_counter;
 *
 * // frequency input  -> PC_6 & PA_3
 * // 50MHz base clock -> PA_5, GPS 1PPS -> PA_1
 * // Connect -> three ports,PA_7,PB_10 and PC_7 connected together
 * // CAUTION!!: SB13 & SB181 must remove from Nucleo-F746ZG board
 *
 * FRQ_CUNTR    fc(49.999992f); // External base clock freq.
 *
 * int main() {
 *   double   cntr_1pps = 0;
 *   double   frequency = 0;
 *   while(true) {
 *      while (fc.status_1pps() == 0) {;}
 *      cntr_1pps = fc.read_avarage_1pps();
 *      while (fc.status_freq_update() == 0) {;}
 *      frequency = fc.read_compensated_freq_data_w_gt(1); // 1sec gate
 *      printf("1PPS/ave = %%11.3f, FREQ. = %11.1f\r\n", cntr_1pps, frequency);
 *   }
 * }
 * @endcode
 */

class FRQ_CUNTR
{

public:

    /** Configure counter
      * @param Base clock Frequency [MHz]
      */
    FRQ_CUNTR(double ex_clock);

    /** Read new frequency data (gate time = 1sec)
      * @param none
      * @return frequency data
      */
    double read_freq_data(void);

    /** Read new frequency data with specific gate time
      * @param gate time [sec] (1 sec to over 1 hour)
      * @return frequency data
      */
    double read_compensated_freq_data_w_gt(uint16_t gt);
    // get raw data
    double read_freq_w_gate_time(uint16_t gt);

    /** Read status (new frequency data is available or not)
      * @param none
      * @return !=0: new data is avairable, 0: not yet
      */
    uint32_t status_freq_update(void);
    
    /** Read avarage measured data GPS 1PPS
      * @param none
      * @return Base clock frequency(average 1(not ave!), 10, 100 & 1000)
      */
    double read_avarage_1pps(void);

    /** Read number of buffered data
      * @param none
      * @return number of data in the buffer
      */
    uint32_t read_num_in_buffer(void);

    /** Read newest measured data GPS 1PPS
      * @param none
      * @return Base clock frequency (newest(no avaraging value))
      */
    uint32_t read_newest_1pps(void);

    /** Read status (new 1PPS data is available or not)
      * @param none
      * @return !=0: new data is avairable, 0: not yet
      */
    uint32_t status_1pps(void);

    /** Read GPS status
      * @param none
      * @return     0: GPS is NOT ready
      *         not 0: 1PPS data is avairable & show gate_time for avarage
      */
    uint32_t status_gps(void);

    /** Reciprocal measurement
      * preparation for Reciprocal measurement -> recipro_start_measure
      * check frequency input as IC trigger -> recipro_check_trigger
      * read IC data -> recipro_read_data
      */
    void     recipro_start_measure(void);
    uint32_t recipro_check_trigger(void);
    uint32_t recipro_read_data(void);

    /** This is a "DEBUG PURPOSE" function
      * Check Base clock frequency on TIM2 or/and TIM8+4
      * print internal data (need to define "DEBUG")
      * @param gate time e.g. 1sec = 1.0f
      * @return Frequency
      *     read_base_clock_frequency -> TIM2 data
      *     read_input_frequency      -> TIM8+4 data
      */
    uint32_t read_base_clock_frequency(double gatetime);
    uint32_t read_input_frequency(double gatetime);

    /** This is a "DEBUG PURPOSE" function
      * print internal data (No need to define "DEBUG")
      * @param none
      * @return none (just print tha data)
      */
    void debug_printf_internal_data(void);      
    void debug_printf_all_buffer(void);

protected:
    void     initialize_Freq_counter(void); // Initialize timers
    void     initialize_TIM2(void);         // Initialize Timer2 (32bit)
    void     initialize_TIM8P4(void);       // Initialize Timer8 + 4 (16+16bit)
    void     set_external_clock(double ex_clock); // Set OC data
    uint32_t calc_1PPS_newest(void);        // Calculate GPS 1PPS newest data
    uint32_t read_ic2_counter_TIM2(void);   // Read TIM2 captured counter data
    uint32_t check_ic2_status_TIM2(void);   // Check TIM2 IC2 status
    uint32_t read_counter_TIM8P4(void);     // Read TIM8+4 captured counter data
    uint32_t check_ic1_status_TIM8P4(void); // Check TIM8 IC2 & TIM4 IC1 status
    uint8_t  read_oc_port_status(void);     // Check TIM2 OC port
    void     set_1sec_gate_time(void);      // Set one second gate time
    uint64_t get_diff(uint64_t new_dt, uint64_t old_dt);

private:
    double   newest_frequency;
    double   ex_clock_freq;
    uint32_t gate_time;
    uint32_t ex_clk_base;
    uint32_t clk_hi_const;
    uint32_t clk_upper_limit;
    uint32_t clk_lower_limit;
    uint32_t  gps_ready;
    // TIM2
    uint32_t counter_tim2;
    uint32_t old_cntr_tim2;
    // TIM8+4
    uint32_t counter_tim8p4;
    uint32_t old_cntr_tim8p4;
    uint16_t sw_ovrflw_tim8p4;
    // 1PPS data
    uint32_t onepps_newest;
    uint8_t  onepps_ready_flg;

};

/*
    Interrupt handler does NOT work following code
    NVIC_SetVector(TIM2_IRQn, (uint32_t)FRQ_CUNTR::irq_ic2_TIM2);
    From this reason, I wrote below code and set interrupt handler
    out side "FRQ_CUNTR" class
    NVIC_SetVector(TIM2_IRQn, (uint32_t)irq_ic2_TIM2);
 */
void irq_ic2_TIM2(void);    // TIM2 IC2 Interrupt control
void irq_ic1_TIM8P4(void);  // TIM4 IC1 Interrupt control (also TIM8 IC2)

}   // Frequency_counter

#endif  // MBED_FRQ_CUNTR